Loudspeaker Basics
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And Passive Speakers?
To be active or not to be active – that is the question... To be active or not to be active – that is the question... 1. Active, passive – the situation 2. Active and passive loudspeaker – the basic difference 3. Passive loudspeaker 4. Active loudspeaker 5. The ADAM loudspeaker: passive option, active optimum 1. Active versus Passive – the Situation In any hifi-system, the loudspeakers are the pivotal component concerning sound quality. That is not to say that the other components do not matter. Nevertheless, it is indisputable that the loudspeaker is decisive for the sound of a hifi-system. It is – besides the acoustical properties of the listening room and the recording itself – the core of any music reproduction. The history of loudspeaker development has produced a great variety of very different systems and designs. The circuit technology of the frequency-separating filter that separates the audio signal into different frequency ranges is determining the design of a loudspeaker. In this respect we distinguish between active and passive systems. Usually, this is a topic that is often underestimated in its importance for sound quality. Active-passive is much more than just a technical negligibility: In fact, the impact of the dividing network on the overall sound of a loudspeaker is substantial. Active or passive – which system is preferable? Considering the aspects mentioned before, it may become a little more comprehensive why the very question comes up over and over again in the hifi-world. For decades it has been spooking as a debate on principles in the journals and magazines and for some time, now, in the web forums. -
Loudspeakers and Headphones 21 –24 August 2013 Helsinki, Finland
CONFERENCE REPORT AES 51 st International Conference Loudspeakers and Headphones 21 –24 August 2013 Helsinki, Finland CONFERENCE REPORT elsinki, Finland is known for having two sea - An unexpectedly large turnout of 130 people almost sons: August and winter (adapted from Con - overwhelmed the organizers as over 75% of them Hnolly). However, despite some torrential rain in registered around the time of the “early bird” cut-off the previous week, the weather during the conference date. Twenty countries were represented with most of was excellent. The conference was held at the Helsinki the participants coming from Europe, but some came Congress Paasitorni, which was built in the first from as far away as Los Angeles, San Francisco, Lima, decades of the twentieth century. The recently restored Rio de Janeiro, Tokyo, and Guangzhou. Companies building is made of granite that was dug from the such Apple, Beats, Comsol, Bose, Genelec, Harman, ground where the building now stands. The location KEF, Neumann, Nokia, Samsung, Sennheiser, Skype, near the city center and right by the harbor proved to and Sony were represented by their employees. be an excellent location both for transportation and Universities represented included Aalto (in Helsinki), the social program. Aalborg, Budapest, and Kyushu. 790 J. Audio Eng. Soc., Vol. 61, No. 10, 2013 October CONFERENCE REPORT A packed House of Science and Letters for the Tutorial Day Sponsors Juha Backmann insists that “Reproduced audio WILL be better in the future.” J. Audio Eng. Soc., Vol. 61, No. 10, 2013 October 791 CONFERENCE REPORT low-frequency performance can still be designed using Thiele- Small parameters in a simulation, and the effect of individual parameters (such as voice coil length and pole piece size) on the system performance can be seen directly. -
Voip V2 Loudspeaker Amplifier (Wireless) Operations Guide
VoIP V2 Loudspeaker Amplifier (Wireless) Operations Guide Part #011096 Document Part #930361E for Firmware Version 6.0.0 CyberData Corporation 3 Justin Court Monterey, CA 93940 (831) 373-2601 VoIP V2 Paging Amplifier Operations Guide 930361E Part # 011096 COPYRIGHT NOTICE: © 2011, CyberData Corporation, ALL RIGHTS RESERVED. This manual and related materials are the copyrighted property of CyberData Corporation. No part of this manual or related materials may be reproduced or transmitted, in any form or by any means (except for internal use by licensed customers), without prior express written permission of CyberData Corporation. This manual, and the products, software, firmware, and/or hardware described in this manual are the property of CyberData Corporation, provided under the terms of an agreement between CyberData Corporation and recipient of this manual, and their use is subject to that agreement and its terms. DISCLAIMER: Except as expressly and specifically stated in a written agreement executed by CyberData Corporation, CyberData Corporation makes no representation or warranty, express or implied, including any warranty or merchantability or fitness for any purpose, with respect to this manual or the products, software, firmware, and/or hardware described herein, and CyberData Corporation assumes no liability for damages or claims resulting from any use of this manual or such products, software, firmware, and/or hardware. CyberData Corporation reserves the right to make changes, without notice, to this manual and to any such product, software, firmware, and/or hardware. OPEN SOURCE STATEMENT: Certain software components included in CyberData products are subject to the GNU General Public License (GPL) and Lesser GNU General Public License (LGPL) “open source” or “free software” licenses. -
Introduction to the Digital Snake
TABLE OF CONTENTS What’s an Audio Snake ........................................4 The Benefits of the Digital Snake .........................5 Digital Snake Components ..................................6 Improved Intelligibility ...........................................8 Immunity from Hums & Buzzes .............................9 Lightweight & Portable .......................................10 Low Installation Cost ...........................................11 Additional Benefits ..............................................12 Digital Snake Comparison Chart .......................14 Conclusion ...........................................................15 All rights reserved. No part of this publication may be reproduced in any form without the written permission of Roland System Solutions. All trade- marks are the property of their respective owners. Roland System Solutions © 2005 Introduction Digital is the technology of our world today. It’s all around us in the form of CDs, DVDs, MP3 players, digital cameras, and computers. Digital offers great benefits to all of us, and makes our lives easier and better. Such benefits would have been impossible using analog technology. Who would go back to the world of cassette tapes, for example, after experiencing the ease of access and clean sound quality of a CD? Until recently, analog sound systems have been the standard for sound reinforcement and PA applications. However, recent technological advances have brought the benefits of digital audio to the live sound arena. Digital audio is superior -
Audio Interface User's Manual
Audio Interface User’s Manual Eurorack Synthesizer Modules 14 HP TABLE OF CONTENTS 1.INTRODUCTION 2.WARRANTY 3.INSTALLATION 4.FUNCTION OF PANEL COMPONENTS 5.SIGNALFLOW & ROUTING 6.SPECIFICATIONS 2 1. INTRODUCTION Audiophile Circuits League. -The main purpose of the ACL Audio Interface module is to interface modular synthesizer systems with professional audio recording and stage equipment. The combination of studio quality signal path, �lexible routing possibilities and a headphoneheadphones ampli�ier, with low capabledistortion, of drivingmakes theboth connection high and low between impedance these different environments effortless and sonically transparent. The ACL Audio Interface offers balanced to unbalanced and unbalanced to balanced stereo lines with level controls. The stereo signal from the auxiliary input,either alsowith with balanced level tocontrol, unbalanced, can be oroptionally unbalanced routed to balanced to and mixed line signals,together or can be muted. The headphone ampli�ier can also get its signal from one or the other line after the level control and mixing stage, or can be muted. Since the ampli�ier is AC coupled only at the input, but not at the output, there is an on-board DC protection circuit included. In case the headphone ampli�ier is driven into clipping, the protection can also be tripped. The module has a soft start function* and one overload indicator for every line. *With the soft start function, the interface switch is turned on after a while after turning on the Eurorack main unit. This function can prevent output of unexpecteddamage to the sound speaker. that another module will emit at startup, which will cause 3 2. -
The Future of Audio
The Future of Audio ■Audio is a cultural treasure nurtured over many years Ever since the dawn of audio technology, there is an ongoing debate whether the sound of audio equipment should be as transparent as possible or display a characteristic of its own, much like a musical instrument. Whichever side of this argument one favors, it is a fact that the reproduction chain from the microphone to the loudspeaker has come a long way. The accumulation of technology has made it possible to increasingly eliminate colorization, resulting in the sound that we have today. But this fact notwithstanding, there is practically no speaker that sounds exactly like another, nor is one amplifier exactly the same as another. Even products using digital technology have their own particular sonic characteristics. Audio technology has evolved to a very sophisticated level. However, the sound of two pieces of equipment may differ, even if their measurement data are the same. This indicates that measurement technology has not yet advanced to duplicate the full depth of human sensory perception. This uncharted territory is where the joy and creativity of audio is born. Paradoxically, the ideal state of audio equipment is one where the equipment itself disappears, allowing listeners to fully immerse themselves in the music. With regard to an amplifier, this means stepping up the level of the recorded signal and correctly delivering it to the loudspeakers without introducing distortion. However, this is easier said than done, and so far the only means of determining whether the speakers are being correctly driven by the amplifier is a subjective evaluation by listening to the sound. -
MINIDISC MANUAL V3.0E Table of Contents
MINIDISC MANUAL V3.0E Table of Contents Introduction . 1 1. The MiniDisc System 1.1. The Features . 2 1.2. What it is and How it Works . 3 1.3. Serial Copy Management System . 8 1.4. Additional Features of the Premastered MD . 8 2. The production process of the premastered MD 2.1. MD Production . 9 2.2. MD Components . 10 3. Input components specification 3.1. Sound Carrier Specifications . 12 3.2. Additional TOC Data / Character Information . 17 3.3. Label-, Artwork- and Print Films . 19 3.4. MiniDisc Logo . 23 4. Sony DADC Austria AG 4.1. The Company . 25 5. Appendix Form Sheets Introduction T he quick random access of Compact Disc players has become a necessity for music lovers. The high quality of digital sound is now the norm. The future of personal audio must meet the above criteria and more. That’s why Sony has created the MiniDisc, a revolutionary evolution in the field of digital audio based on an advanced miniature optical disc. The MD offers consumers the quick random access, durability and high sound quality of optical media, as well as superb compactness, shock- resistant portability and recordability. In short, the MD format has been created to meet the needs of personal music entertainment in the future. Based on a dazzling array of new technologies, the MiniDisc offers a new lifestyle in personal audio enjoyment. The Features 1. The MiniDisc System 1.1. The Features With the MiniDisc, Sony has created a revolutionary optical disc. It offers all the features that music fans have been waiting for. -
Chapter 186 NOISE
Chapter 186 NOISE §186-1. Loud and unnecessary noise §186-3. Permits for amplifying devices. prohibited. §186-4. Stationary noise limits; maximum §186-2. Loud and unnecessary noises permissible sound levels. enumerated. §186-5. Violations and penalties. [HISTORY: Adopted by the Village Board of the Village of Albany 5-11-1992 as Sec. 11-2- 7 of the 1992 Code. Amendments noted where applicable.] GENERAL REFERENCES Disorderly conduct -- See Ch. 110. Parks and navigable waters -- See Ch. 198, §198-1B(2). Peace and good order -- See Ch. 202. §186-1. Loud and unnecessary noise prohibited. It shall be unlawful for any person to make, continue or cause to be made or continued any loud and unnecessary noise. It shall be unlawful for any person knowingly or wantonly to use or operate, or to cause to be used or operated, any mechanical device, machine, apparatus or instrument for intensification or amplification of the human voice or any sound or noise in any public or private place in such manner that the peace and good order of the neighborhood is disturbed or that persons owning, using or occupying property in the neighborhood are disturbed or annoyed. §186-2. Loud and unnecessary noises enumerated. The following acts are declared to be loud, disturbing and unnecessary noises in violation of this chapter, but this enumeration shall not be deemed to be exclusive: A. Horns; signaling devices. The sounding of any horn or signaling device on any automobile, motorcycle or other vehicle on any street or public place in the village for longer than three seconds in any period of one minute or less, except as a danger warning; the creation of any unreasonable loud or harsh sound by means of any signaling device and the sounding of any plainly audible device for an unreasonable period of time; the use of any signaling device except one operated by hand or electricity; the use of any horn, whistle or other device operated by engine exhaust and the use of any signaling device when traffic is for any reason held up. -
Application Notes
Measurement of Loudspeaker and Microphone Performance using Dual Channel FFT-Analysis by Henrik Biering M.Sc, Briiel&Kjcer Introduction In general, the components of an audio system have well-defined — mostly electrical — inputs and out puts. This is a great advantage when it comes to objective measurements of the performance of such devices. Loudspeakers and microphones, how ever, being electro-acoustic transduc ers, are the major exceptions to the rule and present us with two impor tant problems to be considered before meaningful evaluation of these devices is possible. Firstly, since measuring instru ments are based on the processing of electrical signals, any measurement of acoustical performance involves the Fig. 1. General set-up for loudspeaker measurements. The Digital Cassette Recorder Type use of both a transmitter and a receiv- 7400 is used for storage of the measurement set-ups in addition to storage of the If we intend to measure the re- measured data. Graphics Recorder Type 2313 is used for reformatting data and for ., „ J, ,, „ plotting results sponse of one of these, the response ol the other must have a "flat" frequency response, or at least one that is known in advance. Secondly, neither the output of a loudspeaker nor the input to a micro phone are well-defined under practical circumstances where the interaction between the transducer and the room cannot be neglected if meaningful re sults — i.e. results correlating with subjective evaluations — are to be ob tained. See Fig. 2. For this reason a single specific measurement type for the character ization of a transducer cannot be de- r.- n T ,-,,-,■ -. -
Class D Audio Amplifier Basics
Application Note AN-1071 Class D Audio Amplifier Basics By Jun Honda & Jonathan Adams Table of Contents Page What is a Class D Audio Amplifier? – Theory of Operation..................2 Topology Comparison – Linear vs. Class D .........................................4 Analogy to a Synchronous Buck Converter..........................................5 Power Losses in the MOSFETs ...........................................................6 Half Bridge vs. Full Bridge....................................................................7 Major Cause of Imperfection ................................................................8 THD and Dead Time ............................................................................9 Audio Performance Measurement........................................................10 Shoot Through and Dead Time ............................................................11 Power Supply Pumping........................................................................12 EMI Consideration: Qrr in Body Diode .................................................13 Conclusion ...........................................................................................14 A Class D audio amplifier is basically a switching amplifier or PWM amplifier. There are a number of different classes of amplifiers. This application note takes a look at the definitions for the main classifications. www.irf.com AN-1071 1 AN-1071 What is a Class D Audio Amplifier - non-linearity of Class B designs is overcome, Theory of Operation without the inefficiencies -
Loudspeaker Parameters
Loudspeaker Parameters D. G. Meyer School of Electrical & Computer Engineering Outline • Review of How Loudspeakers Work • Small Signal Loudspeaker Parameters • Effect of Loudspeaker Cable • Sample Loudspeaker • Electrical Power Needed • Sealed Box Design Example How Loudspeakers Work How Loudspeakers Are Made Fundamental Small Signal Mechanical Parameters 2 • Sd – projected area of driver diaphragm (m ) • Mms – mass of diaphragm (kg) • Cms – compliance of driver’s suspension (m/N) • Rms – mechanical resistance of driver’s suspension (N•s/m) • Le – voice coil inductance (mH) • Re – DC resistance of voice coil ( Ω) • Bl – product of magnetic field strength in voice coil gap and length of wire in magnetic field (T•m) Small Signal Parameters These values can be determined by measuring the input impedance of the driver, near the resonance frequency, at small input levels for which the mechanical behavior of the driver is effectively linear. • Fs – (free air) resonance frequency of driver (Hz) – frequency at which the combination of the energy stored in the moving mass and suspension compliance is maximum, which results in maximum cone velocity – usually it is less efficient to produce output frequencies below F s – input signals significantly below F s can result in large excursions – typical factory tolerance for F s spec is ±15% Measurement of Loudspeaker Free-Air Resonance Small Signal Parameters These values can be determined by measuring the input impedance of the driver, near the resonance frequency, at small input levels for which the -
Audio Signals Amplitude and Loudness Sound
Intro to Audio Signals Amplitude and Loudness Sound I Sound: vibration transmitted through a medium (gas, liquid, Audio DSP solid and plasma) composed of frequencies capable of being detected by ears. I Note: sound cannot travel through a vacuum. Dr. Deepa Kundur I Human detectable sound is often characterized by air pressure University of Toronto variations detected by the human ear. I The amplitude, frequency and relative phase of the air pressure signal components determine (in part) the way the sound is perceived. Dr. Deepa Kundur (University of Toronto) Audio DSP 1 / 56 Dr. Deepa Kundur (University of Toronto) Audio DSP 2 / 56 Intro to Audio Signals Amplitude and Loudness Intro to Audio Signals Amplitude and Loudness Sinusoids and Sound: Amplitude Sound Volume I Volume = Amplitude of sound waves/audio signals I A fundamental unit of sound is the sinusoidal signal. 2 I quoted in dB, which is a logarithmic measure; 10 log(A ) I no sound/null is −∞ dB xa(t) = A cos(2πF0t + θ); t 2 R I Loudness is a subjective measure of sound psychologically correlating to the strength of the sound signal. I A ≡ volume I the volume is an objective measure and does not have a I F0 ≡ pitch (more on this . ) one-to-one correspondence with loudness I θ ≡ phase (more on this . ) I perceived loudness varies from person-to-person and depends on frequency and duration of the sound Dr. Deepa Kundur (University of Toronto) Audio DSP 3 / 56 Dr. Deepa Kundur (University of Toronto) Audio DSP 4 / 56 Intro to Audio Signals Amplitude and Loudness Intro to Audio Signals Frequency and Pitch Music Volume Dynamic Range Sinusoids and Sound: Frequency Tests conducted for the musical note: C6 (F0 = 1046:502 Hz).