Loudspeaker Design Project
Kyle Persohn Fall 2007 Transducer Theory Michigan Technological University
Loudspeaker Design Project Project Design Loudspeaker
–
Kyle Persohn Kyle
Table of Contents
Datasheet
Design Statement
Initial Design
Revised Design
Final Design
Cabinet Design
Crossover Design
Accounting
Drafting
Construction
As-Built Plans
Initial Listening Evaluations
Testing and Tuning
Final Listening Evaluations
Final Report
Gallery ThankYou
I owevery big thanks to MadisoundSpeaker Components for providingdrivers and crossover parts at educationalrates to makethis projectpossible on a strictbudget. In particular,thank to AdamJohnson who took time out of hisafternoon to helpinspire this final design. I highlyrecommend Madisound to anyspeaker builder looking for an onlineretailer who providesa vastproduct range, competitive pricing,and excellent customer support.
?r' fu-nunaot tladlsound Foi/rr(-totd.€fu,n Scan-spek - LPG Speaker Peerless-Seas-Keiga Gomponents,lnc. HhVi-Audax-Hovland Founhk - Accubn Distributorof Loudspeakers& ComponentsWorldwide Mr. Adam Johnson P.O,Box 1l28g Tcl:008{11-3433 Mafion, YU537ll4 USA F.x:C0E-E31€771 www.firdaound.oofvl *mQmeOlound.cofn
WinSpeakerz Modeled Plots 450 Watts Input Power
Frequency Response Impedence Linear Excursion
Features Specifications
• High SPL ouput Dimensions 12.50” X 61.00” X 13.00” • Deep low-frequency extension W X H X D • Affordable user replaceable Connectors NL-4 Speakon voice coil on tweeters • Horn-loaded directivity Frequency Response 38 Hz – 19.5 KHz (est.) • Dome tweeter clarity Max SPL Output 119 dB (modeled) • Even frequency response • Robust finish Power Handling Up to 450 Watts (est.) • Excellent mechanical grounding • Solid construction Woofers Peerless 10” 830668 Tweeter Morel MDT37
Copyright © 2007 Kyle Persohn, All rights reserved. Other brand names are trademarks or registered trademarks of their respective owners.
Transducer Theory [FA4740] Fall 2007
These HiFi PA speakers are designed for use in the Ensemble Room (209) in the Michigan Tech Rozsa Center. This acoustical system provides a unique balance between volume capability and audio quality bringing you hard hitting bass and elegant treble at impressive volume levels.
Featured in this system are two Peerless 830668 10” Woofers and a Morel MDT37 per cabinet arranged in a “woofer-tweeter-woofer” configuration. The WTW arrangement allows the high and low frequencies to blend on the listening plane (tweeter height). The listening plane is conveniently located at ear level when sitting at the computer workstation in Room 209. The use of two woofers utilizes the combined audio power of two lower sensitivity but higher quality drivers to blast low frequency extension at high volumes. The mini horn-loaded MDT37 boasts the directivity and high SPL of a compression driver while still maintaining the smoothness and lower distortion characteristics of a dome tweeter.
A passive 4th order Linkwitz-Riley crossover network provides the frequency separation between the high frequency tweeter and the low frequency woofers. The L-R design is favorable over the traditional Butterworth design because there is a flat 0db response at the 2 KHz crossover point instead of the normal 3db peak.
This 4th order vented box in constructed primarily of MDF with A/C plywood reinforced baffles and cross-bracing. The dual baffle design keeps cabinet resonance to a minimum because the varying density materials discourage standing waves. Internal dampening features Black Hole acoustic foam to reduce unwanted reflections. The 2” ABS port is located well below listening plane where airflow will not disturb performance. A coating of black truck bed liner gives the outside finish a robust look and feel. Adjustable floor spikes provide cabinet balancing and additional mechanical grounding on carpeted surfaces resulting in tight, punchy bass.
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Designed & Built By: Kyle Persohn
Transducer Theory Loudspeaker Design Statement
Kyle Persohn FA4740 Christopher Plummer Michigan Technological University
Design Statement Persohn
Introduction
The speakers to be built are being designed for the Visual and Performing Arts Department of
Michigan Technological University. They are intended for use in the Hagen Practice (Rozsa 209) also
known as the Ensemble Room. The design will borrow concepts from PA speakers in efforts to achieve
high volumes, however a higher emphasis will be put in fidelity and bass response than one would find
in a traditional PA cabinet. The completed set is expected to meet these requirements:
• Reasonably sized, but well mechanically grounded • Directed coverage • Bass response below 60Hz • High sensitivity/SPL at least 93dB • Driver selections and crossover design that keep audible breakup modes to a minimum • Robustness for a college environment • Strict budget of $600
Budgeting
I started my driver hunt with budget as the primary limiting factor. Using the general guideline of
40% drivers, 35% crossover, 25% cabinet, I allocated a reasonable amount of resources and used that to
limit the overwhelming choices of drivers. Preliminary searches yielded some promising options from
Selenium, Eminence, Peerless, and B&C. I originally disregarding Peerless for not having enough
sensitivity and the Seleniums were negated for their questionable quality. After examining a few
specification sheets, I came to the quick realization there is a heavy tradeoff between cost, sensitivity,
and bass response (and enclosure size; however, I decided I could be the most flexible with this
variable). It is extremely difficult to find economically priced drivers that have a pro-sound level SPL
output without sacrificing low end response.
Drivers
Originally, I was open to 2-way and 3-way designs. With hopes of having better bass response I
looked briefly into 3-way designs. With the additional driver and doubling of crossover parts these
systems met the physical specification requirements the best; however they didn’t quite make the
Page 2 of 9
Design Statement Persohn
budget cutoff. I then focused mainly on 2-way designs primarily for budgetary reasons with hopes of
maximizing whatever bass response I could get out of them. My first potential system had an Eminence
Alpha-8A woofer paired with a B&C DE-10 compression tweeter. I came across the Eminence drivers on
cost based searches and I sought out the B&C tweeters from a review on the Loudspeaker Designer’s
Selection Guide. In contrast to the suspiciously smoothed looking frequency response graphs of the
Selenium drivers, the B&C plots resembled measurements taken by a third party (Stout, 2007). This
system had high sensitivity while still making the budgetary cutoff. Unfortunately when following the
manufactures recommended tweeter crossover point, much of the driver top end break up would be
audible. I chose to replace the B&C with an Eminence PSD2002 which features a 2” voice coil allowing it
to crossover slightly lower and eliminating more of the woofer’s breakup. Upon modeling this design in
WinSpeakerz I was disappointed to discover the design was only going to get a response down to 80Hz
at -3dB (See Figure 1).
Figure 1: Eminence Alpha-8A
Page 3 of 9
Design Statement Persohn
Woofer Selection
A reasonable compromise is to add a second driver to a 2-way system. Having a second driver
expands the possibilities to woofers that might not necessarily have a high enough sensitive by
themselves. By combining two high fidelity drivers their combined SPL output can reach that of pro-
sound drivers. This opened up a realm of drivers I had discounted before due to their inadequate
sensitivity. The Peerless SLS 830668 10” woofer, for example, has an SPL of 88.7dB, but combined with a
second can approach 95dB. This particular driver also has a suitable response down to 38 Hz which is
considerably better than the previously mentioned 2-way design (See Figure 2). This compromise adds
some additional expense to the traditional 2-way design by adding an extra driver; nonetheless, with
half of the crossover parts necessary as a 3-way design this revised 2-way has bass response at a
reasonable cost (Electus, 2001). Although a bit on the pricey side, dual woofers in a 2-way configuration
seem to be the best balance between SPL, bass response, and cost-effectiveness.
Figure 2: Peerless 830668
Page 4 of 9
Design Statement Persohn
Tweeter Selection
With the initial 2-way design it seemed necessary to use a compression driver as a tweeter to get
the high sensitivity required by the system. I looked at many compression drivers that were easily horn-
loadable to obtain some directivity and additional SPL. In my readings, I discovered some of the
negative effects that keep horn-loaded designs out of most studios and are limited to PA systems where
quality isn’t so much of an issue (Newell, 2007). A horn provides additional SPL through directivy but at
the cost of negative diffraction effects in comparison to a flush-mounted dome tweeter. To combat
these issues, I then looked at waveguides which balance the directivity of a horn while exhibiting less
horn-like distortion. A waveguided tweeter probably would work for this application; however,
compression drivers still have a “harsh” reputation that makes them less suitable for high fidelity
applications. The Morel MDT 37 turns out to be an affordable dome
tweeter set back in self contained horn-loaded enclosure (See Figure 3).
This tweeter has SPL capabilities of a PA tweeter with the aural reputation
of a hi-fi transducer (Johnson, 2007). As an added bonus, the MDT 37 has
an affordable and easily replaceable voice coil making it ideal for situations Figure 3: Morel MDT37 where some forgiveness is necessary.
Crossover
With a fairly large woofer and a tweeter that doesn’t extend too far into the midrange, picking a
crossover point was simply a matter of keeping the audible breakup to a minimum. With a 2-way
system there really doesn’t seem to be a good solution to avoiding a crossover around 2 KHz. This is also
another reason I was in favor of a 3-way system at one point. Having two crossovers would allow more
flexibility to avoid 2 KHz, the ear’s most sensitive region. Rather than waste money trying to move the
crossover one way or another it seems most logical to use physics and the behavior of the electronic
crossover components to financial advantage. By keeping the crossover at 2 KHz the capacitors and
Page 5 of 9
Design Statement Persohn
inductors should be more affordable, therefore allowing money to be spent on quality and order instead
of nominal value (Electus, 2001). With the crossover budget dedicated to more components of a higher
quality, I hope to create a fourth order crossover that has a narrower frequency bandwidth around the
ear’s sensitive range instead of a wider band at an alternate frequency. This narrows the problem
directly at the source and overall seems more economically efficient. Again, the 2 KHz crossover is
threading the needle between the breakup points of my drivers therefore not leaving much flexibility to keep my goal of minimizing the audible breakup.
Enclosure
The ideal enclosure design for this system would be a 2nd order sealed box. While the Winspeakerz plot of this arrangement is very appealing, the required volume of 15 cubic feet is quite oversized for this application. An isobaric design using double the drivers was considered, however the extra cost involved cannot be accounted for in the budget. Having the additional drivers would have allowed for a more reasonable enclosure size and still maintain the desirable sealed box response curve.
The next best option turns out to be a 4th order vented design. This enclosure has a reasonable volume around three cubic feet and still has excellent bass response when modeled with an estimate of the room gain. While studying the driver design at Madisound, I got to see how Peerless constructed this particular driver with lots of space for airflow and additional linear displacement for maximum excursion without damaging the driver. When modeled in Winspeakerz, this design reaches down to 38 KHz, well under my target low frequency goal. To handle diffraction I have the smooth channel of the horn working to my advantage moreover I additionally plan to round the front corners of the box with a router to mitigate high frequency diffractions. For easy routing, the enclosure will be constructed mostly out of MDF. Plywood will be added to the front and back panels to provide additional support as well as some dampening from the change in resonant material.
Page 6 of 9
Design Statement Persohn
I would have liked to experiment with some of the internal lattice designs for additional support;
however the complexity and construction tools required make lattices a bit beyond the scope of this
design project (B&W Group Ltd). The B&W bracing methods often employ lots of circles that are cut out
from the main bracing piece. This is ideal because the brace can be one solid unit that is more ridged
than multiple braces joined together. The circle cut outs provide the necessary airflow and volume
reduction while maintaining a strong architectural structure that dates back to usage in Egyptian
aquaducts.
Considering I don’t have the necessary resources to experiment with B&W’s approach, cross-
braces will be added as the North Creek method suggests minimizing standing waves in the cabinet
walls. With one brace placed at just over half-way between the unsupported panels, two different
resonant frequencies are created within the same chamber. The first common wavelength between
these two frequencies doesn’t occur until many multiples beyond the cabinet’s fundamental frequency.
This helps mitigate standing waves within the enclosure. These braces will be constructed out of
plywood and implemented to support the sides not reinforced by the double baffle.
While volume wasn’t a huge consideration of mine from the start, the end result seems reasonable
and I’m comfortable with building a speaker with that volume in a tower configuration. The drivers will
be laid out in a “woofer tweeter woofer” configuration. This will centralize the high frequencies within
the woofers and avoid the undesirable sound of the tweeter
off by itself (Cal Poly AES, 2005). I really like the sound of the
CM-7 towers and I would like to model the character of this
system after their design (See Figure 4). The CM-7 tower is an
MTM speaker designed by North Creek that is a common
benchmark for Loudspeaker comparison around Michigan
Tech. By implementing the North Creek bracing strategy and
Figure 4: CM7 MTM Towers Page 7 of 9
Design Statement Persohn
the WTW design I hope to achieve similar character to the CM-7’s. Lastly, the finished cabinet will be
coated with truck bed liner to provide a durable finish suitable for the college environment.
Application Notes
To raise the cabinet to the desired listening plane, some extra volume will be necessary in a
separate compartment from the loudspeaker itself. This will appear as one integral cabinet; however
the additional space under the cabinet will give the overall system increased height so the tweeter is
level with the listener’s ear. Furthermore, an additional plane should be placed between the speakers to
create one smooth baffle across the stereo image. This space could be expanded to act as a bass trap
once the system is tuned, however will not be included in the scope of this project. Measurements
specific to the acoustical space and system will be necessary to optimize this design.
Summary
This system will serve as a high fidelity PA system. The chosen dual 10” Peerless SLS woofers in
conjunction with a Morel MDT 37 dome tweeter provide the best compromise between cost, frequency
bandwidth, and sensitivity. The horn-loaded dome tweeter is the best example of how this design
bridges the gap between sounding good and sounding loud. This design runs down a hard fault between
PA systems and high fidelity speakers. In doing so tradeoffs had to be made, nonetheless informed
decisions were made to attempt to minimize negative effects on the system as a whole.
Page 8 of 9
Design Statement Persohn
Works Cited
B&W Bowers & Wilikins [Motion picture]. (n.d.). England: B&W Group Ltd.
Dickenson, V. (1991). The Loudspeaker Cookbook (4th ed.). Petersbourogh, NH: Old Colony Sound Lab.
Electus Distribution. (2001). Design Your Own HiFi Speaker Crossovers [Data file].
Jeremy. (2005). Loudspeaker Enclosures [Data file]. Cal Poly AES.
Johnson, Adam. [Interview] Middleton, WI: 2007.
Newell, P. (1995). Studio Monitoring Design. Woburn, MA: Focal Press.
Newell, P., & Holland, K. (2007). Loudspeakers for Music and Reproduction. Burlington, MA: Focal Press.
Stout, B. (2007). Compression Drivers. In LDSG. Retrieved September 29, 2007, from http://ldsg.snippets.org/sect-6.php#DRVRS
Page 9 of 9
Initial Design
My initial design for this project was very budget driven. Not knowing where else to start, I allocated some money for drivers and started hunting on PartsExpress.com. The following pages are specification sheets of eventually rejected drivers. These drivers are 8” woofers and horn ready compression drivers. The 8” woofers were failed attempts at trying to squeeze bass response out of an inexpensive two say system. The choice to use horn-loaded compression drivers for the high end was influenced by their capability to direct sound for high SPL and their wide use in commercial PA speakers.
Shortly after researching these drivers I was granted a much larger budget and quickly moved on to other brand names. The frequency responses of the woofers worried me the most and I knew I would be disappointed with their bass response the most. The horn research I did while investigating this design turned out to be the most valuable information that still had an influence in my final design. PROFESSIONALLINE-Woofer LOUDSPEAKERS 8PW3 Professional8”wooferdesignedtomeetavarietyof PAneedsforsmallandmedium-sizedrooms,withexcellent performanceinthemidandlowfrequencyranges. Forsoundreinforcementinnightclubs,dancinghalls, auditoriums,bandsandalsoforstudiomonitors. Itsgreatefficiencyinsoundreproductionisduetothe excellentcombinationofthedifferentcomponents: -Thelightconemanufacturedwithlongfiberpulp togetherwithasurroundofimpregnatedfabricgivethe arraygreatstability,highyieldandlowdistortion. -Thevoicecoilismadeofhightemperaturewire, woundonKapton® former. -Theepoxypainted reinforcedsteelframeprovides thearraywithhighmechanicalresistance. -Theuseofhighlyresistantadhesivesguarantees optimalcohesionanddurabilityofcomponents.
SPECIFICATIONS Nominaldiameter...... 205(8)mm(in) Nominalimpedance...... 8 W Minimumimpedance@280Hz...... 7.0 W Powerhandling MusicalProgram1 ...... 250W AES2 ...... 125W Sensitivity(1W/1m)averagedfrom100to6,000Hz...... 92dBSPL Powercompression@0dB(Nom.power)...... 3.9dB Powercompression@-3dB(Nom.power)/2...... 2.6dB Powercompression@-10dB(Nom.power)/10...... 0.3dB Frequencyresponse@-10dB...... 70to8,000Hz
1 Specificationstohandlenormalspeechandmusicprogrammaterialwith5%maximum ADDITIONALINFORMATION acceptabledistortiononamplifier.PoweriscalculatedtakingintoaccountthetrueRMS Magnetmaterial...... Bariumferrite voltageatamplifieroutputalongwithtransducernominalimpedance. Magnetweight...... 560(20)g(oz) 2 AESStandard(100-1,000Hz). Magnetdiameterxdepth...... 115x14(4.53x0.55)mm(in) Magneticassemblyweight...... 1,520(3.35)g(lb) THIELE-SMALLPARAMETERS Framematerial...... Steel Fs...... 72Hz Framefinish...... Blackepoxy Vas...... 29(1.02)l(ft)3 Magneticassemblysteelfinish...... Zinc-plated Qts...... 0.81 Voicecoilmaterial...... Copper Qes...... 0.88 Voicecoilformermaterial...... Polyimide(Kapton)® Qms...... 9.64 Conematerial...... Longfiberpulp ho(halfspace)...... 1.22% Volumedisplacedbywoofer...... 0.6(0.021)l(ft)3 Sd...... 0.0250(38.8)m2 (in)2 Netweight...... 1,780(3.92)g(lb) Vd(SdxXmax)...... 58.75(3.59)cm33(in) Grossweight...... 2,000(4.41)g(lb) Xmax(max.excursion(peak)with10%distortion)..2.35(0.09)mm(in) Cartondimensions(WxDxH).20.5x20.5x9(8.07x8.07x3.54)cm(in) Xlim(max.excursion(peak)beforephysicaldamage).8.0(0.32)mm(in) MOUNTINGINFORMATION AtmosphericconditionsatTSparametermeasurements: Numberofbolt-holes...... 4 Temperature...... 25(77)°C(°F) Bolt-holediameter...... 5.0(0.20)mm(in) Atmosphericpressure...... 1,002mb Bolt-circlediameter...... 194(7.64)mm(in) Humidity...... 53% Bafflecutoutdiameter(frontmount)...... 180(7.09)mm(in) Bafflecutoutdiameter(rearmount)...... 185(7.28)mm(in) Thiele-Smallparametersaremeasuredaftera2-hourpowertestusinghalfAESpower. Connectors...... Pushonterminals Avariationof±15%isallowed. Polarity...... Positivevoltageappliedtothepositive (+)terminalgivesforwardconemotion ADDITIONALPARAMETERS Minimumclearancebetweenthebackofthemagneticassemblyandthe bL...... 6.9Tm enclosurewall...... 75(3)mm(in) Fluxdensity...... 1.10T Voicecoildiameter...... 32(1.3)mm(in) Voicecoilwindinglength...... 9.5(31.2)m(ft) ø204 4xø5,0 86 Wiretemperaturecoefficientofresistance(a25).....0.003421/°C Maximumvoicecoiloperationtemperature...... 250(482)°C(°F) qvc(max.voicecoiloperationtemp./max.power)..2.00(3.86)°C/W(°F/W) Hvc(voicecoilwindingdepth)...... 11.0(0.43)mm(in) Hag(airgapheight)...... 6.3(0.25)mm(in) Re...... 6.4 W Mms...... 11.1(0.0245)g(lb) Cms...... 337.2mm/N Rms...... 0.7kg/s
NON-LINEARPARAMETERS Le@Fs(voicecoilinductance@Fs)...... 1.277mH Le@1kHz(voicecoilinductance@1kHz)...... 0.606mH Le@20kHz(voicecoilinductance@20kHz)...... 0.259mH Red@Fs...... 0.14 W 9 50 27 Red@1kHz...... 1.50 W Red@20kHz...... 22.39 W Krm...... 0.563mW Kxm...... 7.261mH Erm...... 0.902 Exm...... 0.716 Dimensionsinmm.
Page:1/2Ed.:00-04/01 PROFESSIONALLINE-Woofer LOUDSPEAKERS 8PW3 RESPONSECURVES(0° AND45°)INATESTENCLOSUREINSIDEAN POLAR RESPONSECURVES ANECHOICCHAMBER,1W/1m 110 50Hz 100Hz 250Hz 0 0 0 30° 330° 30° 330° 30° 330° -6 -6 -6
100 60° -10 300° 60° -10 300° 60° -10 300° -20 -20 -20 90° dB 270° 90° dB 270° 90° dB 270°
90 120° 240° 120° 240° 120° 240°
150° 210° 150° 210° 150° 210° 180° 180° 180° 80
500Hz 800Hz 1.25kHz 0 0 0 30° 330° 30° 330° 30° 330° 70 -6 -6 -6
60° -10 300° 60° -10 300° 60° -10 300°
-20 -20 -20 60 90° dB 270° 90° dB 270° 90° dB 270° 20 200 2k 20k Hz ResponseCurveat0°. 120° 240° 120° 240° 120° 240° ResponseCurveat45°. 150° 210° 150° 210° 150° 210° 180° 180° 180°
IMPEDANCEANDPHASECURVESMEASUREDINFREE-AIR 2kHz 3.15kHz 4kHz 80 90 0 0 0 30° 330° 30° 330° 30° 330° -6 -6 -6
60° -10 300° 60° -10 300° 60° -10 300°
-20 -20 -20 60 45 90° dB 270° 90° dB 270° 90° dB 270°
120° 240° 120° 240° 120° 240°
150° 210° 150° 210° 150° 210° 40 0 180° 180° 180°
PolarResponseCurve.
20 -45
HOWTOCHOOSETHERIGHTAMPLIFIER ThepoweramplifiermustbeabletosupplytwicetheRMSdriverpower.This 0 -90 3dBheadroomisnecessarytohandlethepeaksthatarecommonto 20 200 2k 20k Hz musicalprograms.Whentheamplifierclipsthosepeaks,highdistortion ImpedanceCurve. arisesandthismaydamagethetransducerduetoexcessiveheat.Theuse PhaseCurve. ofcompressorsisagoodpracticetoreducemusicdynamicstosafelevels.
FINDINGVOICECOILTEMPERATURE HARMONICDISTORTIONCURVESMEASUREDAT10%AESINPUT Itisveryimportanttoavoidmaximumvoicecoiltemperature.Sincemoving POWER,1m coilresistance(R)E varieswithtemperatureaccordingtoawellknownlaw, wecancalculatethetemperatureinsidethevoicecoilbymeasuringthe 140 voicecoilDCresistance:
æ R öæ 1 ö ç B ÷ç ÷ B TT A ç -+= 1÷çTA 25 +- ÷ è R A øè a25 ø 120 TAB,T=voicecoiltemperaturesin°C.
RA,R=BvoicecoilresistancesattemperaturesTABandT,respectively.
a25=voicecoilwiretemperaturecoefficientat25°C.
100 POWERCOMPRESSION Voicecoilresistanceriseswithtemperature,whichleadstoefficiency reduction.Therefore,ifafterdoublingtheappliedelectricpowertothedriver wegeta2dBriseinSPLinsteadoftheexpected3dB,wecansaythat 80 powercompressionequals1dB.Anefficientcoolingsystemtodissipate voicecoilheatisveryimportanttoreducepowercompression.
NON-LINEARVOICECOILPARAMETERS 60 Duetoitsclosecouplingwiththemagneticassembly,thevoicecoilin 20 200 20k electrodynamicloudspeakersisaverynon-linearcircuit.Usingthenon- Hz linearmodelingparametersKrm,Kxm,Erm,Exmfromanempiricalmodel, ResponseCurve. wecancalculatevoicecoilimpedancewithgoodaccuracy. DistortionCurve,2ndharmonic. DistortionCurve,3rdharmonic. SUGGESTEDPROJECTS
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TESTENCLOSURE 19-litervolumewithaductø3”by2”length.
Kapton® :DuPonttrademark. EUROPE Address: USAAddress: BRAZIL Address: SELENIUMEUROPE SELENIUM LOUDSPEAKERUSA ELETRÔNICA SELENIUM S.A. Rohrbergstrasse 23B 1701 South Park Court, Bldg 102 BR 386 Km 435 / 92.480-000 D-65343 Eltville - Germany Chesapeake, VA23320 - USA Nova Santa Rita - RS - Brazil Phone: +(49) 6123 601570 Phone: (757) 424-7516/ (800) 562-0510 Fax: +(55) 51 479-1120 Specificationssubjectto Fax: +(49) 6123 601587 Fax: (757) 424-5246 URL: www.selenium.com.br changewithoutpriornotice. E-mail: [email protected] E-mail: [email protected] Page:2/2Ed.:00-04/01 URL: www.seleniumloud speakers.com URL: www.seleniumloudspeakers.com WOOFER 8W4P 8” Woofer with excellent performance in the mid frequency ranges. Its great efficiency in sound reproduction is due excellent combination of different components. This new design is capable of handling up to 300 Watts Continous Music. For sound reinforcement in nightclubs, dancing halls, auditoriums, bands and also for studio monitors. Its great efficiency in sound reproduction is due to the excellent combination of the different components. The epoxy painted reinforced steel frame provides the array with high mechanical resistance, an impregnated fabric surround, impregnated long fiber paper cone, give the array great stability, high yield and low distortion. The 8W4P woofer incorporates a magnetic assembly, of 147mm, of high density of magnetic flux combined with the characteristics above its check to the product high sensibility.
SPECIFICATIONS Nominal diameter...... 205 (8) mm (in) Nominal impedance...... 8 W Minimum impedance @ 325 Hz...... 6.5 W Power handling Peak ...... 600 W Continous Music...... 3001 W NBR...... 1502 W AES...... 1503 W Sensitivity (2.83V@1m) averaged from 100 to 6,500 Hz . . . 96 dB SPL Power compression @ 0 dB (nom. power)...... 3.7 dB Power compression @ -3 dB (nom. power)/2...... 2.6 dB Power compression @ -10 dB (nom. power)/10...... 1.1 dB Frequency response @ -10 dB ...... 100 to 6,500 Hz
1 Power handling specifications refer to normal speech and/or music program material, ADDITIONAL INFORMATION reproduced by an amplifier producing no more than 5% distortion. Power is calculated as Magnet material...... Barium ferrite true RMS voltage squared divided by the nominal impedance of the loudspeaker. 2 Magnet weight...... 1,240 (44) g (oz) NBR Standard (10,303 Brasilian Standard). 3 Magnet diameter x depth...... 147 x 18 (5.78 x 0.71) mm (in) AES Standard (100 - 1000 Hz). Magnetic assembly weight ...... 3,200 (7.05) g (lb) THIELE-SMALL PARAMETERS Frame material...... Steel Frame finish...... Black epoxy Fs...... 107 Hz 3 Voice coil material...... Copper Vas...... 9.2 (0.32) l (ft) Voice coil former material...... Polyimide Qts...... 0.70 Cone material...... Long fiber pulp Qes...... 0.74 Volume displaced by woofer...... 2 (0.07) l (ft3 ) Qms...... 13.2 Net weight...... 3,600 (7.93) g (lb) ho (half space)...... 1.50 % Gross weight...... 3,800 (8.37) g (lb) 2 2 Sd...... 0.025 (38.75) m (in) Carton dimensions (W x D x H) . . . . . 22.5 x 23 x 13.5 (8.85 x 9 x 5.3) cm (in) Vd (Sd x Xmax)...... 50 (3.05) cm(in)3 3 Xmax (max. excursion (peak) with 10% distortion) . . . 2.0 (0.08) mm (in) MOUNTING INFORMATION Xlim (max.excursion (peak) before physical damage) . 16 (0.63) mm (in) Number of bolt-holes...... 4 Bolt-hole diameter ...... 5 x 7 (0.19 x 0.27) mm (in) Atmospheric conditions at TS parameter measurements: Bolt-circle diameter...... 195 (7.67) mm (in) Temperature...... 24 (75) °C (°F) Baffle cutout diameter (front mount)...... 183 (7.2) mm (in) Atmospheric pressure...... 1,020 mb Baffle cutout diameter (rear mount)...... 177 (6.96) mm (in) Humidity...... 56 % Connectors...... Push on terminals Polarity ...... Positive voltage applied to the positive Thiele-Small parameters are measured after a 2-hour power test using half AES power . terminal (red) gives forward cone motion A variation of ± 15% is allowed. Minimum clearance between the back of the magnetic assembly and the enclosure wall...... 75 (3) mm (in) ADDITIONAL PARAMETERS bL ...... 9.88 Tm Flux density...... 1.08 T ø 205 Voice coil diameter...... 46 (1.81) mm (in) 93 Voice coil winding length ...... 14.1 (46.25) m (ft) Wire temperature coefficient of resistance (a25). . . . . 0.00342 1/°C Maximum voice coil operation temperature...... 200 (392) °C (°F) 4x ø 5 x 7 qvc (max.voice coil operation temp./max.power) . . 1.33 (2.61) °C/W(°F/W) Hvc (voice coil winding depth) ...... 12 (0.47) mm (in) Hag (air gap height)...... 8 (0.31) mm (in) Re...... 5.2 W Mms...... 20.2 (0.045) g (lb) Cms...... 325 mm/N ø 183 Rms...... 1.008 kg/s ø 147
NON-LINEAR PARAMETERS Le @ Fs (voice coil inductance @ Fs) ...... 1.186 mH Le @ 1 kHz (voice coil inductance @ 1 kHz)...... 0.787 mH Le @ 20 kHz (voice coil inductance @ 20 kHz)...... 0.459 mH Red @ Fs...... 0.269 W Red @ 1 kHz...... 1.861 W Red @ 20 kHz...... 23.753 W 34 50 8 Krm...... 1.1 mW ø 195 Kxm...... 3.8 mH Erm...... 0.85 Exm...... 0.82 Dimensions in mm. WOOFER 8W4P RESPONSE CURVES (0° AND 45°) IN A TEST ENCLOSURE INSIDE AN POLAR RESPONSE CURVES ANECHOIC CHAMBER, 1 W / 1 m 110 50 Hz 100 Hz 250 Hz 0 0 0 30° 330° 30° 330° 30° 330° 105 -6 -6 -6 60° -10 300° 60° -10 300° 60° -10 300° 100 -20 -20 -20 95 90° dB 270° 90° dB 270° 90° dB 270°
90 120° 240° 120° 240° 120° 240° 85
dB 150° 210° 150° 210° 150° 210° 180° 180° 180° 80
75 500 Hz 800 Hz 1,25 kHz 0 0 0 30° 330° 30° 330° 30° 330° 70 -6 -6 -6 60° -10 300° 60° -10 300° 60° -10 300° 65 -20 -20 -20 60 90° dB 270° 90° dB 270° 90° dB 270° 50 100 200 500 1k 2k 5k 10k Hz 120° 240° 120° 240° 120° 240° Response Curve at 0°. 150° 210° 150° 210° 150° 210° Response Curve at 45°. 180° 180° 180°
IMPEDANCE AND PHASE CURVES MEASURED IN FREE-AIR 2 kHz 3,15 kHz 4 kHz 0 0 0 30° 330° 30° 330° 30° 330° 90 60 -6 -6 -6 60° -10 300° 60° -10 300° 60° -10 300° 80 -20 -20 -20 90° dB 270° 90° dB 270° 90° dB 270° 70 30
60 120° 240° 120° 240° 120° 240°
150° 210° 150° 210° 150° 210° 50 0 180° 180° 180° ohms
40 degrees Polar Response Curve.
30
20 HOW TO CHOOSE THE RIGHT AMPLIFIER 10 The power amplifier must be able to supply twice the RMS driver power. This 3 dB headroom is necessary to handle the peaks that are common to 50 100 200 500 1k 2k musical programs. When the amplifier clips those peaks, high distortion Hz arises and this may damage the transducer due to excessive heat. The use Impedance Curve. of compressors is a good practice to reduce music dynamics to safe levels. Phase Curve. FINDING VOICE COIL TEMPERATURE HARMONIC DISTORTION CURVES MEASURED AT 10% AES INPUT It is very important to avoid maximum voice coil temperature. Since moving POWER, 1 m coil resistance (RE ) varies with temperature according to a well known law, we can calculate the temperature inside the voice coil by measuring the voice coil DC resistance: 110 æ R öæ 1 ö ç B ÷ç ÷ B = TT A + ç - ÷ç A - 25T1 + ÷ 100 è R A øè a25 ø
TAB , T = voice coil temperatures in °C. 90 RAB , R = voice coil resistances at temperatures TAB and T , respectively. a= voice coil wire temperature coefficient at 25 °C. 80 25 POWER COMPRESSION dB 70 Voice coil resistance rises with temperature, which leads to efficiency reduction. Therefore, if after doubling the applied electric power to the driver 60 we get a 2 dB rise in SPL instead of the expected 3 dB, we can say that power compression equals 1 dB. An efficient cooling system to dissipate 50 voice coil heat is very important to reduce power compression.
40 NON-LINEAR VOICE COIL PARAMETERS Due to its close coupling with the magnetic assembly, the voice coil in 30 electrodynamic loudspeakers is a very non-linear circuit. Using the non- linear modeling parameters Krm, Kxm, Erm and Exm from an empirical 2 3 10 Hz 10 model, we can calculate voice coil impedance with good accuracy. Response Curve. Distortion Curve, 2nd harmonic. Distortion Curve, 3rd harmonic. SUGGESTED PROJECTS
For additional project suggestions, please access our website.
TEST ENCLOSURE Closed box, with volume of 455 liters.
www.selenium.com.br Devido aos avanços tecnológicos, reservamo-nos o direito de inserir modificações sem prévio aviso. www.seleniumloudspeakers.com Cód.: 28011062 Rev.: 00 - 01 / 06 PROFESSIONAL LINE - Compression Driver
LOUDSPEAKERS D210Ti
A high quality full range compression driver, is the driver of choice for high performance, high value professional systems. The titanium diaphragm assures high sensitivity, low distortion and smooth, extended frequency response. It is highly recommended for use in monitor speakers, stage monitors and surround speakers in movie theaters. The following highlights the exceptional features of the D210Ti: - titanium dome diaphragm combining a stable structure for mid-frequency reproduction with a low mass, enabling outstanding high frequency reproduction up to 20 kHz; - voice coil is made of high temperature wire wound on Kapton® former to withstand high operating temperatures; - precisely engineered diaphragm structure and alignment mechanism allows for easy, reliable and cost effective repair in case of diaphragm failure.
DRIVER x HORN CONNECTION
SPECIFICATIONS Nominal impedance...... 8 Ω Minimum impedance @ 2,900 Hz...... 7.3 Ω HL14-25 Power handling Musical Program(w/ xover 1,500 Hz 12 dB / oct)1...120 W Musical Program(w/ xover 2,000 Hz 12 dB / oct)1...160 W Sensitivity On horn, 2.83V@1m, on axis2 ...... 107 dBSPL Frequency response @ -06 dB ...... 800to20,000 Hz Throat diameter...... 25(1) mm(in) Diaphragm material ...... Titanium HM25-25 Voice coil diameter...... 44(1.7) mm (in) Re...... 6.0 Ω Flux density ...... 1.6 T Minimum recommended crossover (12 dB / oct)...... 2,000 Hz D210Ti 1 Power handling specifications refer to normal speech and/or music program material, reproduced by an amplifier producing no more than 5% distortion. Power is calculated as true RMS voltage squared divided by the nominal impedance of the loudspeaker. This voltage is measured at the input of the recommended passive crossover when placed between the power amplifier and loudspeaker. HM17-25 MusicalProgram=2xWRMS. 2 Measured with HL14-25 horn, 1,200 - 15,000 Hz average.
ADDITIONAL INFORMATION Magnet material ...... Barium ferrite Magnet weight ...... 666(23.5) g(oz) Magnet diameter x depth...... 115x15(4.52 x 0.59) mm (in) Magnetic assembly weight ...... 1666 (3.67) g (lb) HM11-25 Housing material ...... Plastic Housing finish...... Black Magnetic assembly steel finish ...... E-Coating Voice coil material ...... CCAW Voice coil former material ...... Polyimide(Kapton® ) Voice coil winding length...... 3.5(11.48) m (ft) Voice coil winding depth...... 3.6(0.14) mm(in) Wire temperature coefficient of resistance (α25 ).....0.00435 1/°C Volume displaced by driver...... 0.5()0.017 l(ft)3 Net weight...... 1,727 (3.80) g (lb) Gross weight...... 1,812 (3.99) g (lb) Ø115,0 53 19
MOUNTING INFORMATION Screw W - Ø 1 3 3 18 TPI. Horn connection...... Screw-on1/”-18TPI8 Connectors...... Pushterminals Polarity ...... Positive voltage applied to the positive terminal (red) gives diaphragm motion toward the throat
Ø25
72 Dimensions in mm.
Page: 1/1 Rev.: 00 - 12/02 PROFESSIONAL LINE - Compression Driver
LOUDSPEAKERS D210Ti
RESPONSE AND IMPEDANCE CURVES W/ HL14-25HORN INSIDE AN HARMONIC DISTORTION CURVES W/ HL14-25HORN , 5 W / 1 m. ANECHOIC CHAMBER, 1 W / 1 m
120 25 140
110 20 120
100 15 100
90 10
80 80 5
70 0 60 200 500 1k 2k 5k 10k 20k 200 500 1k 2k 5k 10k 20k Hz Hz Response Curve. Response Curve. Impedance Curve. Distortion Curve, 2nd harmonic. Distortion Curve, 3rd harmonic. RESPONSE AND IMPEDANCE CURVES W/ PLANE-WAVE TUBE, 1 mW
1W 1mW 150 120 25
140 110 20
130 100 15
120 90 10
110 80 5
100 70 0 200 500 1k 2k 5k 10k 20k Hz Response Curve. Impedance Curve. Frequency response and impedance curves measured with 25 mm terminated plane-wave tube.
HARMONIC DISTORTION CURVES W/ HL14-25HORN , 1 W / 1 m.
120
HOW TO CHOOSE THE RIGHT AMPLIFIER The power amplifier must be able to supply twice the RMS driver power. This 100 3 dB headroom is necessary to handle the peaks that are common to musical programs. When the amplifier clips those peaks, high distortion arises and this may damage the transducer due to excessive heat. The use of compressors is a good practice to reduce music dynamics to safe levels. 80 FINDING VOICE COIL TEMPERATURE It is very important to avoid maximum voice coil temperature. Since moving
coil resistance (RE ) varies with temperature according to a well known law, 60 we can calculate the temperature inside the voice coil by measuring the voice coil DC resistance:
R 1 TT B −+= T1 25 +− B A A α R A 25 40 200 500 1k 2k 5k 10k 20k TAB , T = voice coil temperatures in °C. Hz R , R = voice coil resistances at temperatures T and T , respectively. Response Curve. AB AB α25= voice coil wire temperature coefficient at 25 °C. Distortion Curve, 2nd harmonic. Distortion Curve, 3rd harmonic.
Kapton® : Du Pont trademark. Ferrosound® : Ferrofluidics Corporation trademark. BRAZIL Address: ELETRÔNICA SELENIUM S.A. EUROPE Adress: USA Adress: BR 386 Km 435 / 92.480-000 Specifications subject to SELENIUM EUROPE SELENIUM USA Nova Santa Rita - RS - Brazil change without prior notice. Germany USA Fax: +(55) 51 479-1120 Page: 2/2 Rev.: 00 - 12/02 www.seleniumloudspeakers.com www.seleniumloudspeakers.com www.selenium.com.br PROFESSIONALLINE-Driver LOUDSPEAKERS DH200E TheDH200Edriverhasatitaniumdiaphragmcarefully designedtocoverthefrequencyrangefrommidrangeto treblewithhighefficiencyandlowdistortion. Thisastonishingperformancewasachievedusing titanium,alightandstrongspaceagematerialthatallows frequencyreproductionfrom1.5to20kHz.Thisway, compacttwo-waysystemscanbedesignedforuseas stagemonitors,movietheatresystemsandhometheatre soundreproduction. Thedrivermustbeusedwithactiveorpassive crossoverwithcrossoverfrequenciesof2kHzorhigher andaslopeofatleast12dB/oct.WesuggesttheSelenium passivecrossoverLC12M2K8(2,000Hz-12dB/oct). Thevoicecoilismadeofhightemperaturewire woundonKapton® formertowithstandhighoperating temperatures. Apreciselyengineereddiaphragmstructureand alignmentmechanismallowsforeasy,reliableandcost effectiverepairincaseofdiaphragmfailure.
DRIVERxHORNCONNECTION
HM17-25E
HM11-25 SPECIFICATIONS Nominalimpedance...... 8 W Minimumimpedance@4,250Hz...... 6.9 W Powerhandling 1 MusicalProgram(w/xover2,000Hz12dB/oct)...200W DH200E Sensitivity Onhorn,1W@1m,onaxis2 ...... 105dBSPL Frequencyresponse@-10dB...... 1,500to20,000Hz Throatdiameter...... 25(1)mm(in) HM25-25 Diaphragmmaterial...... Titanium Voicecoildiameter...... 46(1.8)mm(in) Re...... 5.8 W Fluxdensity...... 1.55T Minimumrecommendedcrossover(12dB/oct)...... 2,000Hz
1 Specificationstohandlenormalspeechandmusicprogrammaterialwith5%maximum acceptabledistortiononamplifier,withtherecommendedpassivecrossoverconnected. PoweriscalculatedtakingintoaccountthetrueRMSvoltageatamplifieroutputalong withtransducernominalimpedance. HL14-25 MusicalProgram=2xWRMS. 2 MeasuredwithHM17-25Ehorn,1,500-8,000Hzaverage.
ADDITIONALINFORMATION Magnetmaterial...... Bariumferrite Magnetweight...... 429(15)g(oz) Magnetdiameterxdepth...... 102x14(4.02x0.55)mm(in) ø102 70 Magneticassemblyweight...... 1,200(2.65)g(lb) Housingmaterial...... Plastic Housingfinish...... Black W13/8"-18TPI Magneticassemblysteelfinish...... Zinc-plated Voicecoilmaterial...... Copper Voicecoilformermaterial...... Polyimide(Kapton)® Voicecoilwindinglength...... 2.8(9.19)m(ft) Voicecoilwindingdepth...... 2.2(0.09)mm(in) Wiretemperaturecoefficientofresistance(a25).....0.003801/°C Volumedisplacedbydriver...... 0.4(0.014)l(ft)3 Netweight(1piece)...... 1,350(2.98)g(lb) Grossweight(6piecespercarton)...... 8,400(18.52)g(lb) Cartondimensions(WxDxH)...... 35.5x24x9(14x9.5x3.5)cm(in) ø25 55 15 MOUNTINGINFORMATION 3 Hornconnection...... Screw-on1/”-8 18TPI Connectors...... Pushterminals Polarity...... Positivevoltageappliedtothepositiveterminal (red)givesdiaphragmmotiontowardthethroat Dimensionsinmm.
Page:1/2Ed.:00-04/01 PROFESSIONALLINE-Driver LOUDSPEAKERS DH200E
RESPONSECURVEW/HM17-25EHORN INSIDEANANECHOIC HARMONICDISTORTIONCURVESW/HM17-25EHORN,10W/1m. CHAMBER,1W/1m 120 140
110 120
100
100
90
80 80
70 60 200 500 1k 2k 5k 10k 20k 200 500 1k 2k 5k 10k 20k Hz Hz ResponseCurve. ResponseCurve. DistortionCurve,2ndharmonic. DistortionCurve,3rdharmonic. IMPEDANCEANDPHASECURVESMEASUREDW/HM17-25E HORN INFREE-AIR. 15 30 POLARRESPONSECURVES
1kHz 2kHz 4kHz 0 0 0 30° 330° 30° 330° 30° 330° -6 -6 -6
10 15 60° -10 300° 60° -10 300° 60° -10 300°
-20 -20 -20 90° dB 270° 90° dB 270° 90° dB 270°
120° 240° 120° 240° 120° 240° 5 0 150° 210° 150° 210° 150° 210° 180° 180° 180°
8kHz 0 30° 330° 0 -15 -6 200 500 1k 2k 5k 10k 20k 60° -10 300° Hz ImpedanceCurve. -20 DH200Edriver dB PhaseCurve. 90° 270° coupledtoa HM17-25Ehorn.
120° 240°
150° 210° HARMONICDISTORTIONCURVESW/HM17-25EHORN,1W/1m. 180°
120 PolarResponseCurve,Horizontal. PolarResponseCurve,Vertical.
100
HOWTOCHOOSETHERIGHTAMPLIFIER ThepoweramplifiermustbeabletosupplytwicetheRMSdriverpower.This 3dBheadroomisnecessarytohandlethepeaksthatarecommonto 80 musicalprograms.Whentheamplifierclipsthosepeaks,highdistortion arisesandthismaydamagethetransducerduetoexcessiveheat.Theuse ofcompressorsisagoodpracticetoreducemusicdynamicstosafelevels.
60 FINDINGVOICECOILTEMPERATURE Itisveryimportanttoavoidmaximumvoicecoiltemperature.Sincemoving
coilresistance(R)E varieswithtemperatureaccordingtoawellknownlaw, wecancalculatethetemperatureinsidethevoicecoilbymeasuringthe 40 voicecoilDCresistance: 200 500 1k 2k 5k 10k 20k Hz æ R öæ 1 ö ç B ÷ç ÷ ResponseCurve. B TT A ç -+= 1÷çTA 25 +- ÷ è R A øè a25 ø DistortionCurve,2ndharmonic. DistortionCurve,3rdharmonic. TAB,T=voicecoiltemperaturesin°C.
RA,R=BvoicecoilresistancesattemperaturesTABandT,respectively.
a25=voicecoilwiretemperaturecoefficientat25°C.
® Kapton:DuPonttrademark. EUROPE Address: USA Address: BRAZIL Address: SELENIUM EUROPE SELENIUM LOUDSPEAKER USA ELETRÔNICA SELENIUM S.A. Rohrbergstrasse 23B 1701 South Park Court, Bldg 102 BR 386 Km 435 / 92.480-000 D-65343 Eltville - Germany Chesapeake, VA 23320 - USA Nova Santa Rita - RS - Brazil Phone: +(49) 6123 601570 Phone: (757) 424-7516 / (800) 562-0510 Fax: +(55) 51 479-1120 Specificationssubjectto Fax: +(49) 6123 601587 Fax: (757) 424-5246 URL: www.selenium.com.br changewithoutpriornotice. E-mail: [email protected] E-mail: [email protected] Page:2/2Ed.:00-04/01 URL: www.seleniumloudspeakers.com URL: www.seleniumloudspeakers.com Pro Sound Speakers, Drivers & Horns
B&C High Frequency Horns B&C Speakers produces a series of horns for compression drivers ranging from constant directivity models— known for their great consistency in angular coverage—to exponential models, which optimize acoustical loading and sound energy transfer. Standardized driver mounting fl anges give the designer the freedom to choose the best horn/driver combination for each project.
#294-618 #294-620 #294-622 #294-624 #294-626
Min Nominal Throat Mounting Dimensions Price Price Part # Mfg. # Horn Type Freq Dispersion Dia. Type (W x H x D) (1-3) (4-UP) 294-618 ME10 Hyperbolic Cosine ABS 1.5 kHz 90º H x 60º V 1" 2 bolt 5.1" x 5.1" x 3.5" $15.25 $13.80 294-620 ME15 Exponential Cast Aluminum 1.5 kHz 90º H x 60º V 1" 2 bolt 5.4" x 5.9" x 3.5" 26.84 24.65 294-622 ME45 Exponential Cast Aluminum 1 kHz 90º H x 40º V 1" 2 bolt 5.6" x 12.2" x 4.9" 44.15 41.80 294-624 ME60 Constant Directivity Cast Aluminum 800 Hz 90º H x 40º V 2" 4 bolt 9.3" x 10.6" x 7.9" 82.88 77.25 294-626 ME90 Constant Directivity Cast Aluminum 900 Hz 80º H x 60º V 1.4" 4 bolt 10.6" x 10.6" x 5.5" 71.48 66.90
Eminence Professional Horns All Eminence horns are constructed of a high-density, heavy-duty, injection molded ABS. The TI2000 was designed to support even the largest 4-bolt horn driver without the need for extra support brackets.
#290-558 #290-556 #290-550 #290-552 #290-554 #290-560
Min Nominal Throat Mounting Dimensions List Price Part # Mfg. # Horn Type Freq Dispersion Dia. Type (W x H x D) Price Each 290-558 LT250 Constant Directivity 1 kHz 80º H x 60º V 1" 2 bolt/3 bolt 6.7" x 6.4" x 3.8" $29.99 $24.97 290-556 SST1 Constant Directivity 1 kHz 90º H x 40º V 1" 2 bolt/3 bolt 9.8" x 7.7" x 5.2" 34.99 29.97 290-550 H295 Constant Directivity 1 kHz 90v H x 40º V 1" 2 bolt/3 bolt 12.1" x 6" x 4" 34.99 29.97 290-552 H395 Constant Directivity 1 kHz 90º H x 40º V 1" 2 bolt/3 bolt 15.6" x 7.3" x 6.1" 39.99 34.97 290-554 H290 Bi-radial 1 kHz 90º H x 40º V 1" 2 bolt/3 bolt 11.4" x 6.5" x 5.9" 39.99 34.97 290-560 TI2000 Directivity, Radial 500 Hz 60º H x 40º V 2" 4 bolt 11.1" x 9.6" x 10" 69.99 64.97
Mounting type notes: 2 hole- For 2 x 1/4"-20; 3" o.c. mount drivers, 3 hole- For 3 x M6, 2.25" o.c. mount drivers; 4 hole- For 4 x 1/4"-20, 4" o.c. mount drivers.
Metallized Polypropylene Capacitors Dimensions Price Price Part # Value Dia x L (mm) (1-9) (10-99) • 250 VDC Approximate 8 027-420 3.3 uF 17.5 x 31 $1.69 $1.61 • 10% tolerance ohm/6 dB per octave 027-421 4.0 uF 17.8 x 31 1.92 1.83 • High purity blocking caps 027-422 4.7 uF 21 x 32 2.13 2.03 • High current capacity 027-425 5.6 uF 21.5 x 31 2.27 2.16 • Specially designed for Frequency Value 027-424 6.8 uF 19.5 x 46 2.53 2.41 crossovers 027-426 8.2 uF 21.5 x 46 2.93 2.79 800 Hz 25 uF 027-428 10.0 uF 22 x 46 3.75 3.57 The Dayton metallized polypropylene capacitors are 1,000 Hz 20 uF ideal for use in loudspeaker crossover networks. 027-430 12.0 uF 22.5 x 56 4.34 4.14 1,600 Hz 12 uF 027-432 15.0 uF 25 x 56 5.23 4.98 When using them as blocking caps in multi-amped 2,000 Hz 10 uF 027-434 18.0 uF 28 x 56 5.37 5.12 systems, select a cap value that provides a 6 dB/ 3,000 Hz 6 uF 027-436 20.0 uF 28.5 x 56 5.77 5.50 octave crossover about one octave below the actual 5,000 Hz 4 uF 027-438 25.0 uF 30 x 61 6.58 6.27 active crossover point. 027-440 30.0 uF 32 x 61 8.52 8.11 Double capacitance 027-442 40.0 uF 40.5 x 61 10.24 9.75 for 4 ohm loads, halve for 16 ohm Complete list of capacitors on pages 161-163 loads
parts-express.com 235 Pro Sound
Speakers, Drivers & Horns See page 228-233 for our selection of compatible horn drivers. Horn Lenses These molded horn lenses are constructed of high-impact ABS and feature the standard 1-3/8"-18 TPI screw-on driver mounting threads. Some models feature a metal thread insert for added durability. Note: The depth listed in dimensions is mounting depth, without driver, and not necessarily the overall depth of the lens. Horn drivers sold separately.
#270-096 #270-095 #270-099 #270-092 #260-090
Dimensions Hole Cutout Metal Price Price Price Part # Width Height Depth Width Height Threads (1-3) (4-19) (20-UP) 270-092 7-11/16" 6-1/8" 4-3/8" 6-1/4" 4-5/8" No $3.90 $3.50 $2.90 270-095 10-7/16" 4-7/8" 6-3/4" 9-1/4" 3-1/4" No 5.50 5.10 4.80 270-096 12" 4-1/2" 5" 10-3/4" 3-1/4" No 5.50 5.10 4.80 260-090 13-7/8" 6-15/16" 7-15/16" 12-3/4" 5-5/8" Yes 12.94 11.65 10.15 270-099 15-3/16" 5-1/8" 6" 13-5/8" 3-3/4" Yes 10.35 8.90 7.10
Dayton Professional High Frequency Horns Dayton Professional horns are engineered to operate smoothly down to the lowest possible crossover frequency, while maintaining consistent and predictable dispersion throughout their intended range. The medium- #270-304 format constant directivity H110 is intended for large PA cabinets, and its symmetrical mouth permits easy rotation when used in multi-application #270-302 enclosures. The small-format constant directivity H612 will give great performance in short-throw, wide dispersion situations, while the slightly larger H812 employs a traditional exponential flare which provides improved throw and better HF response, but with narrowing dispersion at the highest frequencies. All three horns are precision molded from glass-reinforced polycarbonate. The H812 is designed for two-bolt 1" exit #270-300 drivers, while the H110 and H812 have threaded brass 1-3/8" x 18 TPI throats for screw-on style drivers.
Driver Lowest Rec. Nominal Dimensions List Price Price Part# Mfg. # Mounting Xover Freq. Conversion (H x W x D) Price (1-3) (4-UP) 270-300 H110 1-3/8" x 18 TPI 700 Hz 90º H x 40º V 11-1/2" x 11-1/2" x 9-5/8" $24.99 $19.29 $17.53 270-302 H612 1-3/8" x 18 TPI 1,200 Hz 100º H x 50º V 6-1/4" x 12-3/4" x 4-1/8" 13.99 10.56 9.60 270-304 H812 1" bolt-on 800 Hz 100º H x 60º V 7-7/8" x 12-1/2" x 8-1/8" 24.99 19.21 17.47
Dayton Professional High Frequency Waveguides A waveguide couples the high frequency driver to the listening space without the harmful distortion artifacts of marginally designed and implemented horn loading. It achieves this through the use of non-traditional geometries and lower expansion rates. The resultant #270-306 sound has less distortion, with an “open” characteristic not often #270-308 associated with typical “pinched” or “honky” compression driver/ #270-310 horn combinations. Dayton Professional waveguides reveal all of the articulate, accurate sound reproduction that your HF drivers are capable of delivering, whether the application is live sound, critical studio monitoring, or demanding home audio playback. Two #270-312 versions are available, round or elliptical. Both are precision molded from high-performance plastic, and have industry-standard 1-3/8" x 18 TPI throats for screw-on style drivers. #270-316 #270-314
Lowest Rec. Nominal Dimensions List Price Price Part# Mfg. # Shape Xover Freq. Conversion (H x W x D) Price (1-3) (4-UP) 270-306 H06RW Round 2,500 Hz 75º conical 5-7/8" round x 4" D $5.99 $4.37 $3.97 270-308 H08RW Round 2,200 Hz 75º conical 8" round x 4-3/4" D 6.99 4.77 4.34 270-310 H10RW Round 1,600 Hz 75º conical 10" round x 5" D 9.99 7.60 6.91 270-312 H12RW Round 1,200 Hz 75º conical 11-1/2" round x 5-1/4" D 13.99 9.47 8.61 270-314 H45E Elliptical 3,500 Hz 80º H x 50˚ V 4-11/16" x 4-5/8" x 3-1/8" 5.99 4.40 4.00 270-316 H07E Elliptical 2,200 Hz 80º H x 50˚ V 7" x 7-1/8" x 3-5/8" 8.99 6.23 5.67
236 1-800-338-0531 Revised Design
After researching more reputable driver manufactures’ online and reading a number of reviews I developed a revised design with hopes of better reaching my initial goals. The Eminence woofers are very appealing because of their decent reputation and high sensitivity. Interestingly enough the 8” and the 10” have similar high end compatibles and the 10” even has a more even response overall. Even at a
10” size, the woofer was only recommended for “mid-bass” and couldn’t extend very far below 70Hz. I really felt the pull from all directions in an economic battle between cost, sensitivity, and frequency
response. At this point I thought I was doing very well in terms of SPL capability and my budget was still
healthy however I still wasn’t truly satisfied with the low end response. This design probably would
have done a sufficient job of meeting the majority of the requirements especially with the option if
introducing a stand-alone subwoofer had the bass response been really terrible. Nonetheless, I’m
grateful I was able to develop an even better design that would make this proposal obsolete.
Em inence ALPHA -10A | 4th Order Vented Enclosure
Eminence ALPHA -10A | 2 nd Order Sealed Enclosure (Manufacturer Recommended) Specification
Nominal Basket Diameter 10”, 254mm Nominal Impedance* 8 ohms Power Rating** 150W Resonance 50Hz Usable Frequency Range 57Hz-4.5kHz The Art and Science of Sound Sensitivity*** 95.6 Magnet Weight 20 oz. Gap Height 0.25”, 6.35mm Voice Coil Diameter 1.5”, 38.1mm
Thiele & Small Parameters
Resonant Frequency (fs) 50Hz DC Resistance (Re) 5.31 Coil Inductance (Le) 0.66mH Mechanical Q (Qms) 5.21 Electromagnetic Q (Qes) 0.66 Total Q (Qts) 0.59 Compliance Equivalent Volume (Vas) 82.2 liters / 2.9 cu. ft. ALPHA-10A American Standard Series Peak Diaphragm Displacement Volume (Vd) 114cc Mechanical Compliance of Suspension (Cms) 0.46mm/N Recommended for professional audio mid-bass applications in a small sealed cabinet. BL Product (BL) 7.5 T-M Diaphragm Mass inc. Airload (Mms) 22 grams Efficiency Bandwidth Product (EBP) 76 Maximum Linear Excursion (Xmax) 3.2mm Surface Area of Cone (Sd) 355.4 cm2 Maximum Mechanical Limit (Xlim) 9.1mm
Mounting Information
Recommended Enclosure Volume Sealed 8.5-11.3 liters/0.3-0.4 cu.ft. Vented 28.3-53.8 liters/1.0-1.9 cu.ft. Overall Diameter 10.11”, 256.8mm Baffle Hole Diameter 9.13”, 231.8mm Front Sealing Gasket fitted as standard Rear Sealing Gasket fitted as standard Mounting Holes Diameter 0.23”, 5.7mm Mounting Holes B.C.D. 9.6”, 243.8mm Depth 3.90”, 99mm Net Weight 4.5 lbs., 2 kg Shipping Weight 5.6 lbs., 2.5 kg
Materials of Construction
Copper voice coil Polyimide former Ferrite magnet Vented and extended core Pressed steel basket * Please inquire about alternative impedances. Paper Cone ** Multiple units exceed published rating evaluated under EIA 426A noise source and test standard while in a free-air, non-temperature controlled environment. *** The average output across the usable frequency range when applying 1W/1M into the nominal impedance. Ie: 2.83V/8ohms, 4V/16ohms. Cloth cone edge Eminence response curves are measured under the following conditions: All speakers are tested at 1w/1m using a variety of test set-ups for the appropriate impedance | LMS using 0.25” supplied microphone (software Solid composition paper dust cap calibrated) mounted 1m from wall/baffle | 2ft. X 2ft. baffle is built into the wall with the speaker mounted flush against a steel ring for minimum fractiondif | Hafler P1500Trans-Nova amplifier | 2700 cu.ft. chamber with fiberglass on all six surfaces (three with custom-made wedges) Specification
Nominal Basket Diameter 8”, 203.2mm Nominal Impedance* 8 ohms Power Rating** 125W Resonance 73Hz Usable Frequency Range 58Hz-5kHz The Art and Science of Sound Sensitivity*** 94 Magnet Weight 20 oz. Gap Height 0.25”, 6.35mm Voice Coil Diameter 1.5”, 38.1mm
Thiele & Small Parameters
Resonant Frequency (fs) 73Hz DC Resistance (Re) 5.3 Coil Inductance (Le) 0.44mH Mechanical Q (Qms) 4.6 Electromagnetic Q (Qes) 0.68 Total Q (Qts) 0.59 Compliance Equivalent Volume (Vas) 17.7 liters / 0.6 cu.ft. ALPHA-8A American Standard Series Peak Diaphragm Displacement Volume (Vd) 67cc Mechanical Compliance of Suspension (Cms) 0.28mm/N Recommended for professional audio mid-range applications in a sealed cabinet, or as a mid-bass in a vented BL Product (BL) 7.8 T-M satellite enclosure. Diaphragm Mass inc. Airload (Mms) 17 grams Efficiency Bandwidth Product (EBP) 107 Maximum Linear Excursion (Xmax) 3.2mm Surface Area of Cone (Sd) 210.0 cm2 Maximum Mechanical Limit (Xlim) 7.1mm
Mounting Information
Recommended Enclosure Volume Sealed 5-7 liters/0.18-0.25 cu.ft. Vented 16.7-25.5 liters/0.59-0.90 cu.ft. Overall Diameter 8.24”, 209.2mm Baffle Hole Diameter 7.13”, 181mm Front Sealing Gasket fitted as standard Rear Sealing Gasket fitted as standard Mounting Holes Diameter 0.22”, 5.5mm Mounting Holes B.C.D. 7.75”, 196.9mm Depth 3.25”, 83mm Net Weight 4.3 lbs., 1.9 kg Shipping Weight 5.1 lbs., 2.3 kg
Materials of Construction
Copper voice coil Polyimide former Ferrite magnet Vented core Pressed steel basket * Please inquire about alternative impedances. Paper Cone ** Multiple units exceed published rating evaluated under EIA 426A noise source and test standard while in a free-air, non-temperature controlled environment. *** The average output across the usable frequency range when applying 1W/1M into the nominal impedance. Ie: 2.83V/8ohms, 4V/16ohms. Cloth cone edge Eminence response curves are measured under the following conditions: All speakers are tested at 1w/1m using a variety of test set-ups for the appropriate impedance | LMS using 0.25” supplied microphone (software Solid composition paper dust cap calibrated) mounted 1m from wall/baffle | 2ft. X 2ft. baffle is built into the wall with the speaker mounted flush against a steel ring for minimum fractiondif | Hafler P1500Trans-Nova amplifier | 2700 cu.ft. chamber with fiberglass on all six surfaces (three with custom-made wedges)
COMPRESSION DRIVER PSD:2002 For all bass applications. oooooooooooooooooo Throat Size 1", 25.4mm Impedance 8Ω or 16Ω Power Ratings: (EIA426B specification, 1.6kHz @ 18dB) 80Wrms Resonance 550Hz Usable Frequency Range 1.5Hz - 20kHz Sensitivity (1W @1m on axis on horn) 105dB Magnet Weight 34oz. Voice Coil Diameter 2", 51mm Voice Coil Former DuPont Kapton Diaphragm Material Titanium
Mounting Information
The 1" throat Eminence compression drivers are available in either a bolt-on (PSD:2002) or screw-on (PSD:2002S) format.
Overall Diameter 5.25", 133mm Depth 2.2", 56mm Mounting Holes Diameter (PSD:2002) 2X 1/4-20 on 3" BHC Mounting Holes B.C.D. 3X M6 on 2.25" BHC Mounting Thread (PSD:2002S) 1 3/8" 18 NEF ext.
COMPRESSION DRIVER PSD:2002S
file:///C|/Documents%20and%20Settings/charlotte.b.../Eminence/pages/products02/specsheets/psd2002.htm (2 of 2) [5/30/2002 9:42:48 AM] DE 10 | Hf Compression drivers diaphragm and optimized ceramic magnet assembly allows 1" high frequency compression driver. Low mass mylar high sensitivity and low distortion up to 18 kHz.
Speakers HPL Coaxials HF Compression drivers Horns SPL from 2000 to 18000 Hz. 5 4 3 2 1 Shipping Box (8 units) Shipping Weight (8 units) Net weight (1 unit) Depth Overall Diameter Two M5 holes 180° on 76 mm (3 in) diameter Mounting and Shipping Information Flux Density Diaphragm Material Voice Coil Diameter Recommended crossover Frequency Range Sensitivity (1W/1m) Continuous Program Nominal (2500 –20000 Hz) Power Handling Minimum Impedance Nominal Impedance Throat Diameter Specifications the specified range. Power calculated on rated minimum impedance. Power on Continuous Program is defined as 3 dB greater than the Nominal rating. 12 dB/oct. or higher slope high-pass filter. Driver mounted on B&C ME 10 horn. 2 hours test made with continuous pink noise signal (6 dB crest factor) within factor) crest dB (6 signal noise pink continuous with made test hours 2 Applied RMS Voltage is set to 2.83V for 8 ohms Nominal Impedance. Average Impedance. Nominal ohms 8 for 2.83V to set is Voltage RMS Applied Inductance Winding Material 2 4 3 1 5 220x220x150 mm (8.7x8.7x5.9 in) 6.7 kg (14.7 lb) 90 mm (4.4 in) 53 mm (2.1 in) 0.8 kg (1.8 lb) 25 mm (1 in) 25 mm (1 in) 1.5 – 18 kHz Aluminium 2.5 kHz 0.1 mH 107 dB 1.55 T Mylar 6.3 Ω 40 W 20 W 8 Ω Final Design
In terms of design innovation, perhaps the best class period I had all semester was the one and only I didn’t attend. On a road trip through Madison, Wisconsin I had the privilege of meeting Adam
Johnson of Madisound Speaker Components who inspired my final design. The high sensitivity woofers I had considered in past designs lacked the fidelity that was really desired for this system. At the budget given, a three-way system was quite out of the question although it would work nicely for the SPL and bass desired. To resolve this issue the “woofer-tweeter-woofer” configuration was suggested. The summing of two high quality (but less sensitive) woofers bridges the gap between sensitivity and frequency response. Although there is an additional driver to contribute to the cost the system is still a
2-way so there aren’t any additional crossover parts to increase the overall as in a 3-way system. The driver budget was now being pushed to the limit; moreover, I had a design that boasted high SPL outputs, excellent low end extension down to around 40 Hz at F(-3dB), and drivers from very reputable manufacturers. Having the true feeling of innovation and a unique design that best met the given requirements, I knew I was ready move forward with this design.
MDT 37 Soft Dome Horn Tweeter · Large diameter Hexatech aluminium voice coil · Ferro fluid cooled · High power handling · High max. SPL of 116dB nom. · Replaceable dome/coil assembly · Sturdy gold-plated input tags · Injected polymer faceplate
SPECIFICATIONS Overall Dimensions OD 94mm (3.7") x 58mm (2.28") Nominal Power Handling (DIN) P 200 W (116dB) Transient Power 10ms 1000 W Nominal Impedance Z 8 Ohms Sensitivity 1W/1M 93 dB Frequency Response 1800 - 22000 Hz Resonant Frequency FS 700 Hz VOICE COIL Voice Coil Diameter 28mm (1.1") Voice Coil Height 2.7mm (0.106") Voice Coil Former Aluminium Voice Coil Wire Hexatech Aluminium Number of Layers 2 DC Resistance RE 5.2 Ohms Voice Coil Inductance @ 1KHz LBM 0.09 mH MAGNET SYSTEM Magnet System Type Ferrite Vented HE - Magnetic Gap Height HE 2.5mm (0.098") B Flux density B 1.5T BL Product BXL 3.5 tm Max. Linear Excursion X OPERATIONAL PARAMETERS Moving Mass MMS 0.44 gm. Cone / Dome Material Hand Treated Selected Fabric Effective Piston Area S 6.0 cm² Net Weight Kg. 0.56 Kg.
This very high efficiency and rigid built tweeter is an improved version of the well-established and highly regarded MDT 27. A new horn facia, less deep and optimised for his purpose make this one even better. A better off axis response, improved dispersion and 3dB higher sensitivity above 5kHz are the results as well as a very flat frequency response curve. The damped rear chamber lowers the resonant frequency and smoothens the impedance curve. The ferro fluid, Hexatech aluminium voice coil let this special tweeter handle a tremendous power and provides high efficiency systems with a crystal clear and clean, dynamic sound. Quick service by self-centring dome assembly and very high SPL make this tweeter a perfect match for very high quality PA-systems as well as for high efficiency horn systems. www.moreleurope.com Peerless Data Sheet - ID: 830668 http://www.tymphany.com/peerless/data/830668.htm
print close drawing application
Peerless Data Sheet
Type: SLS 263 SWR 39 115 THSX AL 4L 8 OHM - 830668
Electrical data Voice coil and magnet parameters Nominal impedance Zn 8 (ohm) Voice coil diameter 39.0 (mm) Minimum imp./at freq. Zmin 6.3/126 (ohm/Hz) Voice coil length 24.0 (mm) Maximum impedance Zo 53.2 (ohm) Voice coil layers 4 Dc resistance Re 5.6 (ohm) Height of the gap 8.0 (mm) Voice coil inductance Le 3.3 (mH) Linear excursion +/- 8.0 (mm) Max mech. excursion +/- - (mm) TS Parameters Total useful flux 1.3 (mWb) Resonance Frequency fs 33.3 (Hz) Diameter of magnet 115 (mm) Mechanical Q factor Qms 4.85 Height of magnet 22 (mm) Electrical Q factor Qes 0.57 Weight of magnet 0.87 (kg) Total Q factor Qts 0.51 Factors Force factor Bl 10.2 (Tm) Ratio fs/Qts 65 Mechanical resistance Rms 2.2 (Kg/s) Ratio BL/sqrt(Re) 4.3 Moving mass Mms 51.1 (g) Suspens. compliance Cms 0.45 (mm/N) Special remarks Effective cone diam. D 20.7 (cm) - Effective piston area Sd 335 (cm²) Equivalent volume Vas 69.3 (ltrs) SPL 2.83V/1m at fmin 88.7 (dB)
Power handling Remarks on powertest 100h RMS noise test (IEC) - (W) - Longterm Max System Power (IEC) - (W) IEC268-5 noise signal is used for the powertest.
1 of 2 10/03/2005 10:01 AM Peerless Data Sheet - ID: 830668 http://www.tymphany.com/peerless/data/830668.htm
Measuring methods and conditions are stated in Peerless Standard for Acoustic Measurements (PSAM)
2 of 2 10/03/2005 10:01 AM SLS PLATFORM http://www.tymphany.com/papers/sls_intro.htm
SLS PLATFORM
A new class of midbass and subbass drivers from Peerless.
With the new SLS platform design, Peerless have incorporated many of the features from the highly regarded XLS subwoofer platform. A variety of different cone technologies will be available for the SLS platform. Furthermore a PA cone for high SPL is available. The SLS platform is available in sizes 8" and 12".
A. Low profile of basket The low profile front of the basket is chamfered so that no countersinking is necessary. For rear mounting a rigid cardboard gasket can be fitted.
B. Rubber surround For maximum durability and quality, the SLS subwoofer cones are fitted with rubber surrounds. For other applications cloth or foam surrounds are a possibility.
C. Various cones For customization of sound Peerless is able to supply cones in different configurations. The cost effective pressed and coated paper cone with foam surround will give a crisp and forward sound, with a lean dry bass reproduction. The air-dried cone with rubber surround reproduces an even more rich bass sound.
D. Large dustcap The large dustcap results in a "potent" look and leaves a very good printable platform for customization of the product.
E. Soft roll spider The flat soft roll spider supports the cone movement and allows for more than ±18mm ( 0.8" ) of cone travel. For maximum durability and a long lifetime, a carefully blended mix of cotton and Nomex® has been chosen.
F. Aluminum or kapton voice coil The 39 mm aluminum voice coil former ensures a very good heat dissipation of the voice coil during high power loads and reduces power compression. The high temperature wire stays in position even when temperature reaches 250°C ( 482°F). For special applications where high mechanical Q is needed, a Kapton® or Kapton®MTB voice coil former is available.
G. Undercut polepiece The polepiece is undercut to allow for more cone travel without noise. The undercut also improves linearity, resulting in low distortion.
H. Vented pole piece The pole piece has a very large bore leaving just the necessary steel for the magnetic flux. The result of this is very low compression. The bore has flared ends for quiet cooling.
1 of 2 12/15/2007 3:40 PM SLS PLATFORM http://www.tymphany.com/papers/sls_intro.htm
I. Extended backplate The deeply extended backplate allows for more cone movement and Finite Element Magnetic optimization ensures that the magnet flux is used to maximum by controlling the shape of the steel.
J. Strontium ferrite magnet The powerful Strontium ferrite magnet has been manufactured with high precision which results in narrow frequency response tolerances and low batch variation.
K. Low compression basket The design of the basket is an attractive curved shape which has allowed our designers to open up the basket much more than normally seen on a steel frame without loosing the strength. The low compression design also incorporates venting below the spider to further enhance the openness of the sound.
2 of 2 12/15/2007 3:40 PM SLS 10″ Subwoofer Peerless Application Notes http://www.tymphany.com/datasheet/appview.php?id=37
SLS 10″ Subwoofer
Type Number: 830668 Application notes: Driver Highlights: Coated paper cone, 39 mm voice coil, AL shorting ring in magnet system. Go to Data Sheet
1 of 2 12/15/2007 3:39 PM SLS 10″ Subwoofer Peerless Application Notes http://www.tymphany.com/datasheet/appview.php?id=37
Tymphany™ and $brandname™ are trademarks of Tymphany Corporation. © 2006, Tymphany Corporation. All rights reserved. 010506
2 of 2 12/15/2007 3:39 PM Cabinet Design
I was originally seeking a sealed box design based of a recommendation that it would best fit the design of my chosen Peerless driver. After doing some initial modeling in Winspeakerz, I found the required volume to house two 10” woofers in a sealed enclosure to be enormous. Although size wasn’t a huge initial consideration I could recognize that the sealed enclosure wasn’t reasonable for cost, manageability, and application reasons. As an attempt to salvage the sealed design an isobaric design was considered at one point. This would halve the modeled 15+ cubic feet down to a slightly more manageable 7.5 cubic feet. Consequently, the cost of woofers would double an already tight budget.
Once again costs had to be considered and the idea was dropped. It would have been interesting to test that design in application noting the modeled response is well below 20 Hz with estimated parameters for the Ensemble Room factored into the Winspeakerz plot. Falling back on the 4 th order vented box design, the modeled response reaches down to about 38 Hz at F(-3dB). The original port configuration had to be redesigned after construction because of a tuning estimation error. The 4 th order vented box
made the best enclosure choice because of its reasonable 3 cubic foot volume and promising bass
response. 128 30 75 TATATA 126 28 70
124 26 65
122 24 60
120 22 55
118 20 50
116 18 45
114 16 40
112 14 35
110 12 30
108 10 25
106 Linear Exc Limit 8 20
104 6 15
102 4 10
100 2 5
98 0 mm 0 Ohm SPL 20 50 100Hz 200 500 1k 2k Exc Imp
Driver Parameters Box Parameters Driver: System Type: 4th Order Vented Box Nominal Diameter D = 10 in Box Volume V(B) = 3.056 cu ft Nominal Power P = 0 Watts Closed Box Q Q(tc) = 0.8229 Sensitivity (1W/1m) SPL = 88.7 dB SPL Box Frequency F(B) = 35 Hz Free Air Resonance f(s) = 33.3 Hz Min Rec Vent Area S(vMin) = 23.3 sq in Total Q Q(ts) = 0.51 Vent Surface Area S(v) = 9.425 sq in Electrical Q Q(es) = 0.57 Vent Length L(v) = 4.283 in Mechanical Q Q(ms) = 4.85 Compliance Ratio alpha = 1.604 Equivalent Volume V(as) = 2.45 cu ft Box Loss Q Q(B) = 7 Nominal Impedance Z = 0 Ohms DC Resistance R(e) = 5.6 Ohms Max Thermal Power P(t) = 0 Watts Max Linear Excursion X(max) = 8 mm Max Excursion X(lim) = 0 mm System Parameters Voice Coil Diam. D(vc) = 0 mm No. of Drivers N = 2 Driver Notes: Isobaric Factor I = 1 (1=normal, 2=iso) Peerless SLS 830668 10" Woofer Input Power P(in) = 450 Watts SPL Distance D = 1 m
Michigan Tech System Notes: 1400 Townsend Drive With a correctly turned port, the system gains SPL output, B24, EERC a slight bass boost, and exursion falls within the linear Houghton, MI 49931 906.281.1083 limit. System Name:
4th Order Vented Box
Designer: Kyle Persohn Title: Student
Rev Date: Rev: Crossover Design
Crossover design options were quite limited due to the response of the chosen drivers. I needed a crossover point that split the middle between the breakup modes of the Peerless woofer and the
Morel tweeter. 2 KHz turns out to be a common place to do just this. This value is also very friendly for cost because the physical size and material cost of making components to achieve this are relatively inexpensive. While 2 KHz is often not recommended for its interference with response in the vocal range the 4 th order nature of my chosen Linkwitz-Design has a very narrowband because of the steep roll-off
and sums to 0dB at 2 KHz. Included in this section are nominal values generated from a crossover
calculator. With a set budget, I tried to purchase the best quality components that money would allow.
Specifically, I made sure to use high quality parts for the series components C1, C2, L3, and L4. For the
parallel components I allowed some sacrifices in quality to keep a strict budget. Parallel combinations of
capacitors are occasionally used to get closer to calculated values than nominal sales values allowed.
Source: LaLena DIY Audio Crossover Calculator Capacitor Desired Nominal Value (uF) Brand(s) Value (uF) C1 5.28 4.70 + 0.47 = 5.17 ClarityCap SA C2 10.55 10.00 + 0.47 = 10.47 ClarityCap SA C3 31.66 30.00 + 1.50 = 31.50 ClarityCap SA + Chateauroux Solen C4 7.04 6.80 + 0.22 = 7.02 ClarityCap SA + Chateauroux Solen
Inductor Desired Nominal Brand Value (mH) Value (mH) L1 0.40 0.39 Perfect Winding L2 1.80 1.80 Perfect Winding L3 0.60 0.62 Sidewinder L4 0.30 0.33 Sidewinder
Budget and Accounting
Projected Budget
Drivers Crossover Cabinet Buffer
$50 $100 8% 17% $300 50% $150 25%
Actual Allocations
Drivers Crossover Cabinet Buffer
$30.56 $103.15 5% 17% $305.37 51% $160.92 27%
Note: This budget does not include materials provided already covered by the course fee in addition to materials already carr ied in surplus by the department. An estimated additional $100 was spent on dampening material, wiring, fasteners, floor spikes, finish, etc not accounted for in the buffer amount.. Invoice 284558 Customer PLUMM3
EIN# 39-1954726
Bill To: Ship To:
Christopher Plummer Christopher Plummer Michigan Tech Visual & Perf Michigan Tech Visual & Perf 1400 Townsend Dr, 209 Walker 1400 Townsend Dr, 209 Walker Houghton, MI 49931 Houghton, MI 49931
Date Ship Via F.O.B. Terms 10/15/07 UPS PREPAID Origin Visa Purchase Order Number Order Date Salesperson Our Order Number Verbal 10/15/07 AJ 283930 Quantity Item Number Description Tax Unit Price Amount Required Ship B.O. 4 4 830668 Peerless SLS 10" Paper cone woofer N 47.63 190.52 2 2 MDT37 Morel MDT37 Horn tweeter N 47.37 94.74 1 1 SHIP Shipping Charge N 20.11 20.11
NonTaxable Subtotal 305.37 Taxable Subtotal 0.00 Tax 0.00 Total US Dollars 305.37 Customer Original (Reprinted) Page 1 Invoice 284880 Customer PLUMM3
EIN# 39-1954726
Bill To: Ship To:
Christopher Plummer Christopher Plummer Michigan Tech Visual & Perf Michigan Tech Visual & Perf 1400 Townsend Dr, 209 Walker 1400 Townsend Dr, 209 Walker Houghton, MI 49931 Houghton, MI 49931
Date Ship Via F.O.B. Terms 10/23/07 UPS PREPAID Origin Visa Purchase Order Number Order Date Salesperson Our Order Number Verbal 10/22/07 AJ 284235 Quantity Item Number Description Tax Unit Price Amount Required Ship B.O. 2 2 SA4.7 ClarityCap "SA" 4.7 mfd 630V N 5.38 10.76 4 4 SA.47 ClarityCap "SA" 0.47 mfd 630V N 2.85 11.40 2 2 SA10 ClarityCap "SA" 10.0 mfd 630V N 9.40 18.80 2 2 SA1.5 ClarityCap "SA" 1.5 mfd 630V N 3.40 6.80 2 2 SA.22 ClarityCap "SA" 0.22 mfd 630V N 2.49 4.98 2 2 CP30 30.0mfd Polypropylene Capacitor N 8.13 16.26 2 2 CP6.8 6.8mfd Polypropylene Cap 400V N 2.81 5.62 2 2 SW.39 Sidewinder .39mh #16 AWG N 4.63 9.26 2 2 SW1.8 Sidewinder 1.8 mH N 10.63 21.26 2 2 PL.62 Solen .62MH Air Core #14 Awg N 13.12 26.24 2 2 PL.33 Solen .33MH Air Core #14 Awg N 9.44 18.88 8 8 OX6PAN3/4 6 Pan Head 3/4" Black Ox & Wax N 0.04 0.32 36 36 OX8PAN1 #8 Pan Head 1" Black Ox & Wax N 0.06 2.16 1 1 SHIP Shipping Charge N 8.18 8.18
NonTaxable Subtotal 160.92 Taxable Subtotal 0.00 Tax 0.00 Total US Dollars 160.92 Customer Original (Reprinted) Page 1 I - E- tiwi ft Co- .5!ritt Ti,,,,.tlai rrr Hardu;r;,* tSi Slirld,rtrii"', Hi-,r-rqliiturr.Fll t?!;l +5':-{li.ittr tri F n* r I api ft t3'lI'.rrpt
CUSTOMERNO, JOB NO. PUNCHASEAf8EB|t0. REFERErlCE TEFMS CLERK DATE TIME ?t Ji Fine*rts Ferr*irn H*t SEthF*SX fiane I t-tE-t t4:38
s s o i4iehiu;n l*t'lrn$luurcal tfrriv. H '**+ $+t{.*f 4{ii{'}**ii$t*ir+ !*{!+*n* L bLrl Ltl,, nLi-t . F,aui:Srtrdr'; I Rereiptf,iunb*r': S'i ***{. D l{$tl }6i,1xieilrJX,ri ve P * +**fi lf { *.i+fi{ *'fl *+*.b i${.S* X#ii +iiii& T ilruqhtrn, l'll i?ill T o o 0{t d.rter ig*tfi*07
I r:Ii 1 ;rrflt' OUANI TY SHIPPED ORDERED UM sKtl nEqnPlDTta.ttt Rnt: i UNlTS PRICE/ PER EXTENSION 1,1,:;B F-it ;i,ir(l8i f.'" ;: ,rr1' fil.rii i'ir', r. I i.l 0, f'U'l 6.13[t LIB P F-i:t 5l isr_ill f" jl{15!q111, I l[y, t i i.7! fr -5.:is nrq*d 1:D t *,r if,ilf B.fis
,/ /r' ,l f,l*rchsniiiii' 6.68 // / l;r CI,CIs X {^t.,:.1**-- Total 5;rle S.Ele ' U RECEIVEDBY NO MCGANN BUILDING SUPPLY INC. PAGE 612HANCOCK STREET i HANCOCK MI 49930
MCcA\hlzulLDll.G SLFFLYI PHONE: (906) 4824340 512 FhI.ffi( STREET Xry.nOOKltJ-.l9g30 #-4i8E-'1,3ri0 Dat- !i.D r,ERc s ooo@o1748m Rafas.oca lanr Cl.r}' Loc8 No. 580 L0/23/07 L2249 rq TEF!.IlD: O@e9841 0oO1 rRDR * 382846 CASH/CHECK/BANKCARD
lo 1O/2,/O7 O4r4F DOC# D83013 frrrrr.rrrrr|$Elg MTU FTNE ARTS ************* Vl DELIVER TO ROZSA CENTER TERM*558 EXP: rrrrr * INVOICE * TUESDAY AFTERNOON ************* Sf-E REFtr @32 SLSPR: KM KATRINA MAYNARD BATCHS439 F*JTH$049412 TAX : SCH SCHOOLS, CHURCHESAND AIIS I Z 382846
SUGG UNITS PRICE,/PER EXTENSION TIPPED fl.[f-]ff *91,17 DESCRIPTION 3/4 4X8 MDF 28.49 2 25.64 lPC 51.2B N \I 3/4" 4X8 AC EXTERIOR PLYWOOD 47.99 1 43.t9 /PC 43.L9 APFFIOUED
T}#|.NS Fffi SFTFPI}.IG UIITH I.JSI If,(E A NICE DAVI ct.rsTsERcF/
TA)(ABLE 0 00 94.47 PRIOR DEPOSIT ** NON_TAXABLE 94 47 SUBTOTAL 94 47
TAX AI,IOUNT 0 00 TOTAI A},TOUNT 94 47
Drafting Table of Contents
Drawing Title Page Quantity Material Concept Design 1 - - Three View Plan 2 - - Dimension Plan 3 - - Internal View 4 - - 3D Skeleton 5 - - Outside Front/Back 6 4 MDF Inside Front/Back 7 4 A/C Ply Top/Bottom 8 4 MDF Sides (2 Mirrored) 9 4 MDF False Bottom 10 2 MDF Bracing Sub-Assembly 11 2 A/C Ply Port Sub-Assembly 12 2 ABS Plastic Side Section View 13 - - Top Section View 14 - - Exploded View 15 - -
2 1
B B
A A
TITLE PROJECT Loudspeaker Design
Concept Design SHEET SCALE DRAFTED AND 1 OF 15 1 : 8 DESIGNED BY Kyle Persohn DATE REVISION 10/21/2007 1.0 2 1 2 1
B B
A A
TITLE PROJECT Loudspeaker Design
Three View Plan SHEET SCALE DRAFTED AND 2 OF 15 1 : 10 DESIGNED BY Kyle Persohn DATE REVISION 10/21/2007 1.1 2 1 2 1
.75
11.50
B B
6.25
14.28
22.31
n3.69 n2.84
n10.34 n8.81 61.00 62.50 11.50
n2.88
A n2.41 A 17.00
.75
12.50 13.00
TITLE PROJECT Loudspeaker Design
Dimension Plan SHEET SCALE DRAFTED AND 3 OF 15 1 : 10 DESIGNED BY Kyle Persohn DATE REVISION 10/21/2007 1.5 2 1 2 1
B B
A A
TITLE PROJECT Loudspeaker Design
Internal View SHEET SCALE DRAFTED AND 4 OF 15 1 : 10 DESIGNED BY Kyle Persohn DATE REVISION 10/21/2007 1.1 2 1 2 1
B B
A A
TITLE PROJECT Loudspeaker Design
3D Skeleton SHEET SCALE DRAFTED AND 5 OF 15 1 : 7 DESIGNED BY Kyle Persohn DATE REVISION 10/21/2007 1.1 2 1 2 1
12.50 .75
B B
62.50
A A
TITLE PROJECT Loudspeaker Design
Outside Front/Back SHEET SCALE DRAFTED AND 6 OF 15 1 : 8 DESIGNED BY Kyle Persohn DATE REVISION 10/21/2007 1.1 2 1 2 1
11.00 .75
B B
61.00
A A
TITLE PROJECT Loudspeaker Design
Inside Front/Back SHEET SCALE DRAFTED AND 7 OF 15 1 : 8 DESIGNED BY Kyle Persohn DATE REVISION 10/21/2007 1.1 2 1 2 1
11.50 .75
B B 12.50
A A
TITLE PROJECT Loudspeaker Design
Top/Bottom SHEET SCALE DRAFTED AND 8 OF 15 1 : 4 DESIGNED BY Kyle Persohn DATE REVISION 10/21/2007 1.1 2 1 2 1
.75 5.75
B B
48.00
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TITLE PROJECT Loudspeaker Design
Sides SHEET SCALE DRAFTED AND 9 OF 15 1 : 8 DESIGNED BY Kyle Persohn DATE REVISION 10/21/2007 1.3 2 1 2 1
10.00 .75
B B 11.50
A A
TITLE PROJECT Loudspeaker Design
False Bottom SHEET SCALE DRAFTED AND 10 OF 15 1 : 4 DESIGNED BY Kyle Persohn DATE REVISION 10/31/2007 1.1 2 1 2 1
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9.53 8.50
.75
6.00
39.00
4.00
A A 9.00 4.00
1.00 TITLE PROJECT Loudspeaker Design
Bracing Sub-Assembly SHEET SCALE DRAFTED AND 11 OF 15 1 : 6 DESIGNED BY Kyle Persohn DATE REVISION 10/31/2007 1.2 2 1 2 1
n2.47
B B
13.75
A A
7.75
TITLE PROJECT Loudspeaker Design
Port Sub-Assembly SHEET SCALE DRAFTED AND 12 OF 15 1 : 4 DESIGNED BY Kyle Persohn DATE REVISION 11/4/2007 1.2 2 1 2 1 C .16
1.00
B B
12.25 A A
C SECTION C-C
TITLE PROJECT Loudspeaker Design
Side Section View SHEET SCALE DRAFTED AND 13 OF 15 1 : 8 DESIGNED BY Kyle Persohn DATE REVISION 10/21/2007 1.3 2 1 2 1
SECTION G-G
B B
GG
A A
TITLE PROJECT Loudspeaker Design
Top Section View SHEET SCALE DRAFTED AND 14 OF 15 1 : 10 DESIGNED BY Kyle Persohn DATE REVISION 10/21/2007 1.2 2 1 2 1
B B
A A
TITLE PROJECT Loudspeaker Design
Exploded View SHEET SCALE DRAFTED AND 15 OF 15 1 : 8 DESIGNED BY Kyle Persohn DATE REVISION 10/21/2007 2.1 2 1
Construction Notes
11-01-2007 I’m a little worried about the initial cuts because all of the initial MDF cuts weren’t supposed to fit on two sheets of stock MDF. Somehow they all did. I’ve double and tripled checked the measurements against my AutoCAD cut sheets and the Inventor solid models but all appears to be correct. Something doesn’t add up. Also, I’m extremely disappointed with the A/C plywood. It was not worth the cost at all. I would prefer a standard sheet of B/B over the stock I got any day. It is extremely warped and quite ridged so it splinters easy when cutting.
11-03-2007 I cleaned up all of the panel saw rips with the table saw. All of the main cabinets pieces are cut down to size so I have two complete shells at least. I also made the discovery that MDF comes in 49” stock sheets. This accounts for the mismatch on my cut sheet. The two side panels don’t spill over onto a new sheet anymore so one whole less sheet of MDF has been eliminated. After much fun trying to setup jigs for the router I have started cutting the T-slots in for the false bottom and the cross-bracing joint on the side panels.
11-06-2007 Utilizing a dry assembly with clamps I predrilled the two baffles together to create precision alignment in preparation for the gluing stage. Application of glop between the inner and outer baffles went quite well. The A/C ply is warping a lot, so much that the MDF is bending with it. At least it centered nice because of my pre-assembly. I also cut the majority of the cross-bracing pieces. I may want to adjust the thickness of the vertical runners to provide a larger gluing surface for the cross pieces to stick to.
11-08-2007 Today, I learned that PVC does not come in a nominal 2.5” ID size contrary to what the Autodesk Inventor Standard Parts Library thought. I’ve settled on stepping down to 2” because the 3” modeling doesn’t look like it is going to work very well. I have new numbers from Winspeakers and will need to update the drafting accordingly. I still think this port seems extremely long and suspect something may be wrong with it. I will also be using ABS plastic instead of PVC because it is black and won’t require painting to blend in with my intended truck-bed finish coat.
11-11-2007 I finished all of the T-slotting with the new Makita router. The guide is really great for one-pass routes but isn’t too handy for slots wider than the width of the router bit. If I had a ¾” end-mill bit the one pass fence technique would work wonders. However since the ½” bit is being used to make a wider slot I probably would have been better off with the custom fence approach as used before.
Because the stamped frame of my woofers is so thin, I have made the decision not to recess them. As the gasket tape gets compressed to the MDF there is virtually no thickness offset. I will still continue to recess the tweeter which has a much thicker edge and naturally the high frequencies are more sensitive to diffraction.
Using a “poor man’s caliper” comprised of scrap wood, a square, and a tape measure I’ve successfully estimated the diameter of the drivers and found them to be slightly larger than listed in their PDF’s. The holes sizes will be rounded up to the next nominal size on the circle jig to allow some wiggle room. The router bit isn’t deep enough to make it through both layers of baffle so the driver holes will have to be approached from both sides. While I didn’t want to do this for accuracy sake, it really won’t matter in the end because the mismatch will be on the interior and therefore not visible.
11-13-2007 Finished routing the driver holes. Glue. Glue. Glue. Got two coffins now. Assembly with the drywall screws was a horrible choice because the thread is too fine for MDF.
11-14-2007 Wiring and mounting everything took way longer than expected. The crossover is setup externally and the drivers are wired to the NL-4 Speakon jack so the crossover can be tuned without removing the back. Speaking of the back, the warped nature made it difficult to put on. I’m not looking forward to having to remove it for any reason.
Perhaps the most important lesson of the night was on how to properly wire inductors. After much aggravated troubleshooting I found out that the ends of two my inductors didn’t come pre-filed so they weren’t passing current. After re-crimping the terminal ends to the conductive inductor the low frequencies we’re much more prominent. Warped back was interesting
11-15-2007 02:00am They make sound! HF + LF
Drafting Table of Contents
Drawing Title Page Quantity Material Concept Design 1 - - Three View Plan 2 - - Dimension Plan 3 - - Internal View 4 - - 3D Skeleton 5 - - Outside Front/Back 6 4 MDF Inside Front/Back 7 4 A/C Ply Top/Bottom 8 4 MDF Sides (2 Mirrored) 9 4 MDF False Bottom 10 2 MDF Bracing Sub-Assembly 11 2 A/C Ply Port Sub-Assembly 12 2 ABS Plastic Side Section View 13 - - Top Section View 14 - - Exploded View 15 - -
2 1
B B
A A
TITLE PROJECT Loudspeaker Design
Concept Design SHEET SCALE DRAFTED AND 1 OF 15 1 : 8 DESIGNED BY Kyle Persohn DATE REVISION 12/15/2007 1.1 2 1 2 1
B B
A A
TITLE PROJECT Loudspeaker Design
Three View Plan SHEET SCALE DRAFTED AND 2 OF 15 1 : 10 DESIGNED BY Kyle Persohn DATE REVISION 12/15/2007 1.2 2 1 2 1
.75
11.50
B B
6.25
14.28
22.31
n3.69 n2.84
n8.81
61.00 62.50 11.50
n2.38
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.75
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TITLE PROJECT Loudspeaker Design
Dimension Plan SHEET SCALE DRAFTED AND 3 OF 15 1 : 10 DESIGNED BY Kyle Persohn DATE REVISION 12/15/2007 1.6 2 1 2 1
B B
A A
TITLE PROJECT Loudspeaker Design
Internal View SHEET SCALE DRAFTED AND 4 OF 15 1 : 10 DESIGNED BY Kyle Persohn DATE REVISION 12/15/2007 1.2 2 1 2 1
B B
A A
TITLE PROJECT Loudspeaker Design
3D Skeleton SHEET SCALE DRAFTED AND 5 OF 15 1 : 7 DESIGNED BY Kyle Persohn DATE REVISION 12/15/2007 1.2 2 1 2 1
12.50 .75
B B
62.50
A A
TITLE PROJECT Loudspeaker Design
Outside Front/Back SHEET SCALE DRAFTED AND 6 OF 15 1 : 8 DESIGNED BY Kyle Persohn DATE REVISION 12/15/2007 1.2 2 1 2 1
11.00 .75
B B
61.00
A A
TITLE PROJECT Loudspeaker Design
Inside Front/Back SHEET SCALE DRAFTED AND 7 OF 15 1 : 8 DESIGNED BY Kyle Persohn DATE REVISION 12/15/2007 1.2 2 1 2 1
11.50 .75
B B 12.50
A A
TITLE PROJECT Loudspeaker Design
Top/Bottom SHEET SCALE DRAFTED AND 8 OF 15 1 : 4 DESIGNED BY Kyle Persohn DATE REVISION 12/15/2007 1.2 2 1 2 1
.75 5.75
B B
48.00
61.00
.75
.25
A A
11.50 .75
TITLE PROJECT Loudspeaker Design
Sides SHEET SCALE DRAFTED AND 9 OF 15 1 : 8 DESIGNED BY Kyle Persohn DATE REVISION 12/15/2007 1.4 2 1 2 1
10.00 .75
B B 11.50
A A
TITLE PROJECT Loudspeaker Design
False Bottom SHEET SCALE DRAFTED AND 10 OF 15 1 : 4 DESIGNED BY Kyle Persohn DATE REVISION 12/15/2007 1.2 2 1 2 1
1.50
11.00
.75 B B
9.53 8.50
.75
6.00
39.00
4.00
A A 9.00 4.00
1.00 TITLE PROJECT Loudspeaker Design
Bracing Sub-Assembly SHEET SCALE DRAFTED AND 11 OF 15 1 : 6 DESIGNED BY Kyle Persohn DATE REVISION 12/15/2007 1.3 2 1 2 1
B B
n2.38
n2.07 2.00
A A
TITLE PROJECT Loudspeaker Design
Port Sub-Assembly SHEET SCALE DRAFTED AND 12 OF 15 1 : 4 DESIGNED BY Kyle Persohn DATE REVISION 12/15/2007 2.1 2 1 2 1
J .16
1.00
B B
12.25 A A
J SECTION J-J
TITLE PROJECT Loudspeaker Design
Side Section View SHEET SCALE DRAFTED AND 13 OF 15 1 : 8 DESIGNED BY Kyle Persohn DATE REVISION 12/15/2007 1.4 2 1 2 1
SECTION K-K B B
KK
A A
TITLE PROJECT Loudspeaker Design
Top Section View SHEET SCALE DRAFTED AND 14 OF 15 1 : 10 DESIGNED BY Kyle Persohn DATE REVISION 12/15/2007 1.3 2 1 2 1
B B
A A
TITLE PROJECT Loudspeaker Design
Exploded View SHEET SCALE DRAFTED AND 15 OF 15 1 : 8 DESIGNED BY Kyle Persohn DATE REVISION 12/15/2007 2.2 2 1 Initial Listening Evaluation
My very first initial listening evaluation took place at 2am in the morning as described in my testing journal. Because I was so exhausted I did not notice the left channel’s woofers weren’t hooked up. I decided to discard this evaluation in favor of discussing the one that was done as an entire class with consistent tracks for comparison. I like the low end extension thus far compared to other two-way systems but I’m hoping to still get more out of it. John’s 3-way system has been motivation for trying to get the most out of this system. Being able to hear his system next to mine has given me good benchmarks for not accepting my bass response as is and striving to achieve as close to a 3-way’s sound as I can. The stereo image is well contained within the cabinets but isn’t so narrow it sounds mono. This should work out well for a “sitting at desk” application. The upper mid to highs are a bit harsh at this point. While testing I hope to see what dampening can do for this and if that doesn’t solve the problem investigate impedance correction or a pad on the tweeter.
The class’s reviews of my speakers have some mixed results but given we all haven’t had much experiencing loudspeakers I suppose that is to be expected. For example, as a class we can’t seem to agree whether the mid frequencies are too present or not present enough. Either way, the important part is most agree there isn’t uniformity in this region and I will make a point to address it in testing.
Most of my classmates are impressed with the bass response as-is, but a few recognize that there is still room for improvement. Comments about the stereo image and depth are inconsistent. Some feel that the image is narrow for the physical size of the speakers, others feel that the size fits the spacing nicely, and still yet there are also those that believe the image graciously fills the room. Most importantly, no one justified there response in this category as something that detracts from any of my design goals.
We all agree that 212 has some limitations as a test environment so will pay more attention to these comments when the speakers are in there actual home. Included in this section are the actual responses that this summary is based off of. Testing and Tuning Notes
11-15-2007 – Initial Listening It’s 2am and I’m just so thrilled they are making noise ahead of the due date anything sounds glorious coming from these cabinets. I think the system is a little bit right biased at this point and the tweeter is a little hot but other than that I’m quite happy with them for a first run. The punchyness is welcome and they are very capable of loud volumes.
11-16-2007 Now that my brain is functioning again all of the drivers are hooked up for the second run. Having the left woofers unplugged last night explains the bias and tweeters being overpowering. The bass has greatly improved but the upper-mids are a little harsh still.
11-29-2007 - First In-Class Listening I like how these speakers handle loud volumes compared to some of the other systems. I’m not getting the frequency extension that John has but the notes are a lot crisper however. Hopefully dampening will solves some of the upper-mid issues.
11-30-2007 – Initial Testing before ANY modifications [212, <1M, 4010] Key Format: T[Test Number]-[Left|Right]-[Tweeter|Woofer|Full Range]-[Modifications ] Ex. T1-R-FR-T^-1 = Test 1, Right Speaker, Full Range, Tweeter Inverted
Looks like I need to re-tune the port. Back to Winspeakers for reworking the length.
I might have some cancellation issues at the crossover point.
Looks like phase inverting one of the drivers will solve the cancellation issue. There is still some upper- mid boost that will need to be addressed with dampening and impedance correction.
Between tests I added BlackHole, completely re-tuned the port, and coated them in truck bed liner.
12-07-2007 – Testing with Modifications [McArdle, 2M, M30]
Impedance graph is looking much better with the correctly tuned port. There is still a little bit of oddity but I want to listen to the system before making any drastic changes. If anything the port could be slightly shorter to even out the two humps surrounding the tuning frequency.
Phase inverting the woofer makes all the difference between summing and cancellation at the crossover point. There is still an ugly boost slightly above 1K however. Looks like dampening didn’t completely resolve the issue as I had expected.
I added a capacitor and a resistor hooked in series across the positive and negative terminals of the woofers to add impedance correction. Values were calculated based off the formula in the Loudspeaker Cookbook . As shown above, the correction circuit nicely reduces the impact of the rising woofer impedance with frequency.
The correction circuit did an effective job of eliminating the undesired bump above 1K. The frequency response is now pretty stable (within 3dB) overall. Accurate resolution on this test equipment is from about 100 Hz up to 10 KHz. Regions outside this range should be ignored.
The left speaker had some similar issues to start out as well.
All of the corrections were applied and it now looks almost like the right speaker. There is just a slight dip around the crossover that doesn’t seem to be summing quite as well as the right speaker did.
As an interesting side note, here is a comparison between an EarthWorks M30 linear test microphone and a Behringer ECM8000 with all other variables kept identical.
M30 M.S.R.P - $795.00 ECM8000 M.S.R.P - $64.99
After listening to the system again in 212 I have decided that the harshness has subsided with the changes I made in McArdle. The newly tuned port produces acceptable bass so I will not mess with the tuning any further. The addition of floor spikes also improved the transient response. fourier.jpg (JPEG Image, 500x361 pixels) http://imgs.xkcd.com/comics/fourier.jpg
1 of 1 12/17/2007 2:56 PM Final Listening Evaluation
The final listening evaluation took place in 210. Given a number of circumstances I didn’t think my speakers performed as well in this space as they did in others. First, they are specifically designed for a close together, up front, and seated listening place. The off-centered distant evaluation I did in 210 made seemed very spacious and open. Without being such a confined space they suffered from the lack of room gain and didn’t feel quite as bassy as before. I think there were significant improvements from before in spectral uniformity but oddity of the layout made those improvements hard to distinguish. I am confident my speakers are performing better than before from tests in other locations which I will discuss further in my Final Repot. I was, however, displeased with the performance in 210.
Flaws in the standardized testing environmental layout and logistical procedures led to very mixed responses from the audience. For one thing, I made it clear in my design statement that these were designed for rocking out at high SPL levels, but I never got to actually demonstrate this in testing.
While it was important to have a few tracks that each set played for comparison sake there was much need for some builder selected tracks that could exemplify the unique characteristics of the constructed loudspeaker. While everyone didn’t particularly love the way they turned out, the general consensus seemed to be that they were “well fitting of the design goals” and “suiting their purpose well.” Because the comments on stereo image and depth were so varied from reviewers scattered about the room it was hard to determine what comments if any were very legitimate. It is also interesting to note that mine were the first setup and they performed much differently without any of the others present in the room. Once the “wall of sound” was created ,my system seemed to get muddier than it was all by itself.
Again, the raw data collected from my peers is included in this section for reference. Final Report
All things considered I’m very happy with the final product I have produced as an outcome of this project. I set out to make a high fidelity speaker capable of reaching pro-sound levels similar to a PA system. While the constructed system wouldn’t necessarily be good for sound reinforcement in a concert hall space, the speakers perform well in their new home, the Hagen Practice Room in the Rozsa
Center. From a measurement standpoint, the numbers and graphs speak well for this system. Also, and perhaps more importantly, they perform well acoustically and my peers even agree that they fit their intended purpose.
After testing and tuning I was extremely pleased with this system’s performance in Walker 212. I listened extensively to many different tracks including ones from the Transducer Theory Test CD, the
MTU Studio Test CD, and my own personal selections which better represented material most likely to be used on this system in the future. I was particularly pleased with the low end clarity of the upright bass and also how I Know My Love didn’t sound congested and overwhelming like it did on other systems. I wasn’t as impressed with the sound in Walker 210 as previously discussed in my Final
Listening Evaluation. More importantly the speakers fit in quite well in Rozsa 209 where they were intended to live. Most of my objections to the way they sound in that room are from other elements in the signal chain. The class D Sampson amplifier doesn’t quite match up to the Rotel that had been used for prior listening. Additionally, the M-Audio FireWire 410 most likely has the same high frequency shelf as the one in Walker 212 which would explain some upper harshness. I conclude that based on what I know they are capable of from tests in 212 some changes to the signal chain and perhaps a little bit of physical rearrangement could improve their performance in 209.
From a measurement standpoint, my system has impressive plots as well as plots that leave some uncertainty. The measurements taken in McArdle theatre where reflections could easily be isolated show an impressively flat response as shown in Figure 1.
Figure 1: Right Cabinet, McArdle Theatre
In Rozsa 209, the reflections off the walls clutter the frequency response to the point where it looks much uglier. Measurements were taken on the listening plane where a user would sit at the computer workstation. When eliminating the reflections, the low frequency resolution only extends down to 2
KHz making the measurement completely useless. Shown in Figure 2 is an average of both channels in
209 with no reflections isolated.
Figure 2: Average of LR, Rozsa 209
A sense of agreement that I met my design goals well is the most valuable information I got from my peers during evaluations. Without giving reviewers any prior instruction and few of them having much relevant experience to speaker reviewing conflicting and confusing reports are to be expected. From comments beyond the review sheets themselves I got a good sense that this system exceeds the expectations of a typical 2-way system in terms of frequency while being capable of ridiculously high sound pressure level outputs. Given this feedback in conjunction with my budget staying in control, I feel I met my design requirements quit well. The final product balances low- frequency extension, loudness capability, and cost in a highly effective package.
As with any project there were many valuable learning experiences gained from “do it yourself” nature of this construction process. In future designs, I would be certain to hand pick my stock wood
sheets to avoid the bad experience I had with the A/C plywood. I also know how to correctly tune a
vented enclosure so my port could be more proportional and less noisy in the future. While the
aesthetics of this system fit their purpose well, I look forward to producing an eye pleasing professional
looking system that borrows the black baffle on stained enclosure idea. Although it doesn’t show up on
the outside, caulking would have been much easier and neater had I done it before securing the bracing
internally. Lastly, given more flexibility in dimensions the next system I design will have pieces that are more easily manageable on the given construction equipment. Smaller or at least portioned panels were much easier to produce accurately which would seem to directly impact the visual and acoustic turnout of the final product.
I am also proud of many cunning ideas whether intentional or not that worked out to make my building process more sucessful. Planning cut sheets to keep similar sized edges on the same pass through the saw or at least during the same fence set made all the difference when matching up joints for assembly. Additionally, the T-slotted fittings made for a rock solid cross-bracing and appeared to be less of a headache than the “box in a box” design that was employed by many of my peers. A 4-pole connector is a must for testing and tuning. Even with an easily removable back having the option to initially run the crossover externally without hassle made adjustments much simpler.
In the end, I’m proud to present a unique set of speakers to the Michigan Tech Visual and
Performing Arts Department. I’m a bit disappointed I can’t take them home, but they will perform well in their new home. Along the way I’ve learned some valuable lessons about what worked and what didn’t so I can make improvements when it comes time to build a set my own.