Bass Reproduction. for Jazz Recordings That Spotlight the Dynamic and Tonal Range of the Trumpet

EQUIPMENT REPORT

ELECTRONICALLY REPRINTED FROM september 2011

Pioneer SP-BS41-LR

robert j. reina loudspeaker

DESCRIPTION Two-way, reflex- loaded, stand-mounted loudspeaker. Drive-units: 1" soft-dome tweeter, 5.25" woofer. Crossover frequency: 2.5kHz. Frequency range: 55Hz– 20kHz. Nominal impedance: 6 ohms. Sensitivity: 85dB/2.83V/m. Maximum input power: 130W. DIMENSIONS 7.9" (200mm) W by 13.75" (350mm) H by 8.7" (220mm) D. Weight: 10.25 lbs (4.7kg). FINISHES Black vinyl. he buzz was all over the audiophile ’net. “Pioneer has a new bookshelf speaker that’s killer SERIAL NUMBERS OF UNITS for the money!” REVIEWED JFNV00015BUC (both). Hmm, I thought. Pioneer. Speakers? PRICE $149.99/pair. Approximate To be fair, I’ve had the Pioneer brand on my mind for well over 30 years. The company number of dealers: >20 (a limited set was my brand of choice for car-stereo electronics in the 1970s, for Dolby S cassette decks of overall Pioneer dealers). in the ’80s, for DVD players in the ’90s, and for plasma TVs in the ’00s and ’10s. I felt a bit MANUFACTURER Pioneer Electronics guilty that I hadn’t focused on the fact that Andrew Jones, the very same design guru who (USA) Inc., PO Box 1540, Long Beach, came up with Pioneer’s TAD Reference One loudspeaker ($70,000/pair), had had a hand in designing Ta few two-channel speaker models starting at $99.99/pair. The audio gossip was all about the second CA 90801-1540. Tel: (800) 421-1404. model from the bottom of Pioneer’s speaker line, the SP-BS41-LR ($149.99/pair). I thought I’d better Web: www.pioneerelectronics.com. get a pair and review them.

www.Stereophile.com, September 2011 Pioneer SP-BS41-LR

Description manufacturing process. Although he and his dynamic articulation made me want to listen This two-way, rear-ported SP-BS41-LR, a team designed the SP-BS41-LR in the US and to piano recordings. Pianist Marilyn Crispell black bookshelf model, has an attractively produced its first prototype here, he sent his uses quite a bit of silence, space, and decay in curved cabinet designed to increase stiff- team to Pioneer’s factory in China to closely her music, which fits in nicely with the am- ness and reduce internal standing waves. The supervise the first production run, to ensure bient sound Manfred Eicher likes to create in drive-units are a 1" soft-dome tweeter and a that the production units matched his final all recordings for his label, ECM. In the title 5.25" cone woofer. I discussed with Andrew prototype. track of Crispell’s Amaryllis (CD, ECM 1742), Jones what he’d tried to accomplish with the I sat the SP-BS41-LRs on my usual Celes- I could hear every little detail of her phrasing, SP-BS41-LR. He told me he’d surveyed most tion Si stands, loaded with lead shot and sand. presented cleanly and with plenty of air—the of the $150/pair speakers on the market and The speaker’s attractive grilles of metal mesh, rich sonority of her instrument shone through. had concluded that most were designed with which separately protect the tweeter and Recordings of more challenging piano works, cosmetics as a design criterion, but with little woofer, are not removable. such as the Allegro moderato of Rachmaninoff’s attention paid to sound quality. The biggest Sonata 1, in Robert Silverman’s recording (CD, shortcoming he found was in the competi- Listening Stereophile STPH019-2), were reproduced tion’s crossovers. Most had a crossover consist- I was immediately taken with the subtle with perfect clarity—Silverman’s crisp phrasing ing of either a single capacitor, or a capacitor low-level articulation and lack of midrange on his Steinway was very easy to follow. and an inductor. Jones believes that it’s impos- coloration in all recordings of voices. George John Medeski’s frantic upper-register im- sible to create a seamless integration of mid/ Harrison’s lead vocal in his “Something,” from provising on Lee Morgan’s “Afrique,” from woofer and tweeter with a crossover compris- the 2009 remastering of the Beatles’ Abbey Medeski, Martin & Wood’s Tonic (CD, Blue ing only one or two elements. He was able Road (CD, Apple 3 82468 2), was rich and Note 5 25272), was reproduced without a to design a six-element crossover using quality silky, with every subtle nuance of his phrasing trace of smearing or harshness, and the sense parts, without exceeding his considerable con- intact. Higher up the audioband, the Pioneer of air in Tonic, the large club where this album straints of low manufacturing cost. rendered Jonatha Brooke’s voice in “Linger,” was recorded, was quite evident. Before the Jones also designed the SP-BS41-LR’s drive- from her Steady Pull (CD, Bad Dog BDR SP-BS41-LRs appeared in my house, I’d never units, paying special attention to the cone pro- 60801-2), with an airy and biting but elegant heard so inexpensive a loudspeaker reproduce file, voice-coil winding, and magnet structure, quality, and perfectly captured this singer’s complex high-frequency transients with such and felt fortunate in finding a cabinet supplier tendency to develop a “howly” quality in loud- realism. I therefore began to mine my jazz who was able to execute his curved design er passages, as I’ve heard her do in concert. collection for percussion recordings, specifi- within his cost parameters. The final step was The ability of the SP-BS41-LR to reproduce cally those featuring drummer Paul Motian. the integration of Jones’s design into Pioneer’s layers of midrange detail with lifelike low-level In addition to Crispell’s Amaryllis, I cued up

measurements

measured the Pioneer SP-BS41-LR’s frequency that the specified 6 ohms figure is too pessimistic. response in the farfield with DRA Labs’ MLSSA system The impedance traces have glitches evident at 180, and a calibrated DPA 4006 microphone. For the 470, and 700Hz, which implies the existence of some nearfield measurements I used an Earthworks QTC-40 kind of enclosure resonances at these frequencies. 1 microphone,I whose ⁄4" capsule provides only a minimal Investigating the vibrational behavior of the enclosure obstacle to the flow of air through the port. The Pioneer panels with a simple plastic-tape accelerometer revealed speaker’s B-weighted sensitivity on the tweeter axis was a rather lively cabinet. The side panels (fig.2) have 85.8dB/2.83V/m, which is within experimental error of ridges of resonant energy evident at 570Hz, as antici- the specified 85dB. The electrical impedance remained pated, but also at 470Hz; and while a lower-frequency above 6 ohms at all frequencies (fig.1, solid trace). The ridge is visible, this is just above 200Hz, rather than at average was closer to 9 ohms, which both means that the the 180Hz I had expected from the impedance plot. SP-BS41-LR—who thought of that name?—will be an easy I would expect some lower-midrange congestion to load for the partnering amplifier to drive, and suggests stem from this behavior.

Fig.1 Pioneer SP-BS41-LR, electrical impedance (solid) and phase Fig.2 Pioneer SP-BS41-LR, cumulative spectral-decay plot calculated from (dashed). (2 ohms/vertical div.) output of accelerometer fastened to center of side panel (MLS driving voltage to speaker, 7.55V; measurement bandwidth, 2kHz).

www.Stereophile.com, September 2011 Pioneer SP-BS41-LR

Motian, Joe Lovano, and Bill Frisell’s Time and of times, I found myself ignoring Hendrix’s Requiem, with Timothy Seelig conducting the Time Again (CD, ECM 1992). In “Cambodia,” trademark rhythm guitar and being transfixed Turtle Creek Chorale and the Women’s Cho- Motian’s role is to provide largely arrhythmic by that glockenspiel melody, whose upper rus of Dallas (CD, Reference RR-57CD), the textural colors, and through the Pioneer his harmonics shimmered and decayed without pipe organ’s pedal notes never lost definition, phrasing on ride cymbal was as natural as I’d getting lost in the mix. the ensemble remained clear and crisp with heard from any budget-priced speaker. Part of the reason for the SP-BS41-LR’s transient realism was its ability to reproduce extended and uncolored high frequencies, I was very impressed with both the quantity and the way the highs seamlessly integrated with the midrange. I found myself searching and the quality of the Bass reproduction. for jazz recordings that spotlight the dynamic and tonal range of the trumpet. On the title track of Miles Davis’s ’Round About Midnight I was very impressed with both the quantity no loss of definition even at fairly high volume (CD, Columbia CK 40610), his horn was silky and the quality of the Pioneer’s bass reproduc- levels, and the “air” of the recording venue (a and holographic, with just the right amount of tion even in my large listening room, which church) was quite audible. metallic bite and long decay. On a mellower has proved a challenge for the smallest book- With rock music, the SP-BS41-LR was able note, in the ballad “Tristan’s Way,” from Liam shelf speakers at the low end. In “Aurora,” to produce a good sense of high-level dynamic Sillery’s Priorité (CD, OA2 Records 22082), from Jon Hassell’s Last Night the Moon Came drive and heft, especially for so small a speak- Sillery stretches out the long, slow, soulful Dropping Its Clothes in the Street (CD, ECM er. However, if I pushed the Pioneers too hard, trumpet melody before moving on to an im- 2077), there is an interlude between Peter the limitations of the laws of physics did come provisational passage. Through the Pioneers, Freeman’s thundering electric bass guitar and into play. I cranked up “Vrooom,” from King the lower register of Sillery’s horn bathed the the electronic bass of Jamie Muhoberac that Crimson’s Thrak (CD, Discipline 8 40324 rhythm section in a mellifluous glow. at times drops below the bass guitar’s bottom 2), and although the distinction between the The SP-BS41-LR’s reproduction of the note. Although Pioneer claims a lower limit bass lines of Tony Levin on Chapman Stick highs let me focus on things in rock recordings of 55Hz for the SP-BS41-LR (we’ll see what and Trey Gunn on bass guitar was quite clear, that I’d never noticed before. In the instru- John Atkinson’s measurements tell us), I never when I tried to push the SP-BS41-LR past mental introduction to “Little Wing,” from noticed a lack of bass clarity with this track, or 95dB in my large room I began to lose a bit Jimi Hendrix’s Axis: Bold As Love (CD, MCA any lower-register notes on which the speaker of detail, the speakers sounded a bit squashed MCAD-1601), a track I’ve heard many dozens seemed to peter out. Similarly, in John Rutter’s and compressed, and some smearing emerged.

Turning to the Pioneer’s acoustic behavior, the low- to reach –6dB at the port tuning frequency. frequency saddle in the impedance-magnitude trace Higher in frequency, the Pioneer’s farfield output (fig.3) suggests that the rear-panel port is tuned to 60Hz. The is respectably even before featuring a small peak between red trace in fig.3 shows the output of the port, measured 10 and 15kHz. The plot of the speaker’s horizontal disper- in the nearfield. It peaks between 40 and 90Hz, but its sion (fig.4) shows that the small suckout below the top- smooth upper-frequency rolloff is marred by two high-Q octave peak fills in to the speaker’s sides, but also that the resonances, at 570 and 900Hz. The blue trace in this tweeter’s output above 10kHz falls off rapidly, which will graph is the nearfield output of the woofer. As expected, ameliorate the audibility of that peak. Lower in frequency, it has a sharp notch at the port tuning frequency of the Pioneer’s dispersion is broad and even, with no sign of 60Hz. The black trace below 300Hz in fig.3 is the sum the usual off-axis flare at the bottom of the tweeter’s pass- of the nearfield woofer and port responses. The peak band. In the vertical plane (fig.5), suckouts in the crossover apparent in the upper bass is actually an artifact of the region develop more than 5° above and below the tweeter nearfield measurement technique; the SP-BS41-LR’s low axis, which suggests that the stands used be tall enough frequencies will actually be close to flat before rolling off to place the listener’s ears close to the tweeter axis.

Fig.3 Pioneer SP-BS41-LR, anechoic response on tweeter axis at 50", Fig.4 Pioneer SP-BS41-LR, lateral response family at 50", normalized to averaged across 30° horizontal window and corrected for microphone response on tweeter axis, from back to front: differences in response response, with nearfield woofer (blue trace) and port (red) responses 90–5° off axis, reference response, differences in response 5–90° off axis. and their complex sum respectively plotted below 300Hz, 1kHz, 300Hz.

www.Stereophile.com, September 2011 Pioneer SP-BS41-LR

Comparisons I compared the Pioneer SP-BS41-LR ASSOCIATED equipment ($149.99/pair) with my trusty entry-level benchmark, the Paradigm Atom v.5 ($250/ ANALOG SOURCES VPI TNT IV, Rega Planar 3 turntables; Immedia, pair), as well as with the Wharfedale Diamond Syrinx PU-3 tonearms; Koetsu Urushi, Clearaudio Virtuoso Wood cartridges. 10.1 ($350/pair), which I reviewed in the July DIGITAL SOURCES Lector CDP-7T, Creek Destiny CD players. 2011 issue. PREAMPLIFICATION Vendetta Research SCP-2D phono stage, Audio Valve The Paradigm Atom v.5 had a midrange Eclipse line stage. richness similar to that of the Pioneer, with POWER AMPLIFIER Audio Research Reference 110. quite good inner detail. However, the Atom’s sound had a darker quality—its highs weren’t INTEGRATED AMPLIFIER Creek Destiny. as extended or as clean as the SP-BS41-LR’s— LOUDSPEAKERS Paradigm Atom v.5, Wharfedale Diamond 10.1. and its transients seemed a bit more blurred. CABLES Interconnect (all MIT): Magnum M3, MI-350 CVTwin Terminator, Finally, the Paradigm’s midbass was a touch MI-330SG Terminator. Speaker: Acarian Systems Black Orpheus. warmer, the Pioneer’s cleaner. ACCESSORIES Various by ASC, Bright Star, Celestion, Echo Busters, Salamander Designs, The Wharfedale Diamond 10.1’s midrange Simply Physics, Sound Anchor, VPI. —Robert J. Reina was as clean as the Pioneer’s and seemed to re- solve even more detail. The 10.1’s highs were more extended, however, as well as more silky, bookshelf speaker in-house, it raises the bar. Sure, spending two or three times as much can airy, and delicate. The Wharfedale’s bass was One would expect the sound of a $149.99/ buy you a number of speakers that will do one as tight and clean as the Pioneer’s, but seemed pair bookshelf model to include some seri- or more things better than the Pioneer. But more extended. Finally, the Diamond 10.1’s ous compromises and tradeoffs, but within Andrew Jones set overall dynamic range seemed wider than ei- its size limitations, the Pioneer SP-BS41-LR himself a very high ther the Pioneer’s or the Paradigm’s. has none. It is a dynamic, coherent, and color- design goal with the less reproducer of music, with quite convinc- SP-BS41-LR, and Summing Up ing bass for its size. It should give lovers of all he has fully attained Over the last few years, I’ve continued to be genres of music hours of convincing realism that goal—and with- impressed by what speaker designers are ac- in the listening room, so long as those listen- out compromise. An complishing at lower and lower price points. ers keep their volume levels within reason and impressive achieve- It seems that every time I get a new affordable don’t attempt to rewrite the laws of physics. ment indeed! nn

measurements, continued

In the time domain, the SP-BS41-LR’s step response on the tweeter axis (fig.6) suggests that both drive-units are connected in positive acoustic polarity. The decay of the tweeter’s step smoothly blends into the start of the woofer’s step, which implies optimal crossover design. The cumulative spectral-decay plot (fig.7) is impressively clean, with only a very slight amount of delayed energy apparent at 1.7kHz. The measured performance of Pioneer’s SP-BS41-LR would not be out of place in a $1000/pair speaker, let alone one costing just $150/pair. Color me impressed. —John Atkinson Fig.6 Pioneer SP-BS41-LR, step response on tweeter axis at 50" (5ms time window, 30kHz bandwidth).

Fig.5 Pioneer SP-BS41-LR, vertical response family at 50", normalized to response on tweeter axis, from back to front: differences in response 45–5° above axis, reference response, differences in response 5–45° Fig.7 Pioneer SP-BS41-LR, cumulative spectral-decay plot on tweeter axis below axis. at 50" (0.15ms risetime).

Posted with permission from the September 2011 issue of Stereophile ® www.stereophile.com. Copyright 2011, Source Interlink Media, Inc. All rights reserved. For more information on use of this content, contact Wright’s Media at 877-652-5295.

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