AES Technical Committee

Automotive Audio

Chair:	Richard S Stroud	(Send Email)
Vice Chair:	Tim Nind	(Send Email)

Areas of Concentration

- Automotive Transducers

- Vehicular System Design

- Objective System Evaluation

- Subjective System Evaluation

- New Audio Sources

- Automotive Mulitchannel Sound

- Noise production and cancellation

Recent/Planned Activities

Latest Activities:

137th AES Convention in Los Angeles: Meeting of AES Technical Committee for Automotive Audio

Automotive Audio Conference in California being considered

Automotive Audio Trends

1. Vehicles with built-in Internet capability (via high speed phone connection, etc.) could present numerous music and talk selections at higher quality than most other data-reduced sources. At least one OEM is working on personal audio to allow people to have the same data & source material they have at home in the car. Connectivity may be based on the user's mobile phone. Some OEM's are considering using a dedicated server to control quality.

The current mobile phone system would be burdened to near unusablilty by a high percentage of customers using a large number of music channels, so minimizing station selection, data reduction and speeds beyond 4G will likely be necessary. This is especially true in urban areas at current cell tower density levels.

There is, however, a growing number of people that are using this kind of service with little difficulty. The though that this will replace FM, AM, Satellite and CD has occurred to some persons and others see this is unlikely and at least premature.

2. Premium receivers are beginning to appear that do not include CD players. Increasingly larger USB drives are becoming a primary music storage medium, along with bluetooth-connected smart phones with their often large music libraries.

3. There is an interest in providing sounds for very quiet cars such as electric vehicles. These include "engine start" and "engine running" sounds for inside the vehicle and pedestrian safety sounds for outside the vehicle. This was a major discussion topic at the Munich AA Conference.

4. SSD's are replacing mechanical hard drives as preferred storage when cost permits.

5. Objective measurement is still battling subjective listening tests as a final authority for OEMs. SPL vs. distortion measurements are quite good now, and directionally correct frequency response measurements are improving. Spatial measurement capability has been developed and evaluated.

6. Trends towards higher performance audio systems is in direct conflict with recent trends of cost and weight reduction of components in automobiles. Increased application of neodymium magnets may help.

7. Neodymium metal costs are still high and are variable. As of this writing, they are falling. Current price is around $55/kg (China). It is risky for a supplier to quote neodymium speakers because of price variability.

With high neo prices, speaker customers need a strong set of specifications to insure that suppliers maintain speaker sensitivity and Xmax.

8. Planar style speakers are now found in vehicles. These are not totally flat, but have profiles of 10 mm or less. Some examples have shown very low sensitivity.

9. HD radio components are now for sale. In the US, AM HD radio offers much higher fidelity and FM HD offers additional program sources. Because of the fidelity difference on AM, rapid switching in fringe areas must be carefully managed. Spectral compression artifacts are mentioned with HD AM.

10. "Surround sound" is almost mandatory in high-end automotive systems, even when the source is limited to two-channel (via upmix algorithms). Some listeners sense that some surround systems provide limited envelopment on both stereo and most "surround" source material.

11. There is almost universal branding of audio systems in luxury cars. Newer brands are emerging. The maximum number of speakers used in luxury vehicle systems seems to be leveling out at 18 ± 2.

12. Voice recognition systems for telephone and navigation functions are now quite sophisticated and enjoy wide application.

13. Active noise cancellation by the audio system is being used for exhaust drone under condition of cylinder deactivation.

14. Active road noise bass and/or level compensation now enjoy a widespread market presence. Basic versions are available in many OEM head units while some high-end premium systems have more sophisticated implementations.

Simple systems use the speedometer signal to apply predefined loudness curves. Others use microphones to measure the current cabin noise, after separating the music, allowing more targeted equalization or bass/level compression to be applied.

15. Switching audio is now common in automotive amplifiers. Switching audio cost are becoming comparable with older AB amplifiers, as the heat sink requirement is minimized. Important for electric vehicles is the low current draw under most all audio power output conditions.

16. Aftermarket audio now represents a very small part of the automotive audio market. OEM head unit and speaker reliability is comparatively good, and performance of OEM systems is often quite good enough for most listeners.

17. Rear seat audio performance may be important in China and other countries, as some who can afford automobiles can also afford drivers.

18. There are still parts of the world where 5.1 and high-level premium audio are not featured in most vehicle's audio lineups. These systems can take advantage of inexpensive, powerful audio DSP systems to improve performance.

19. Audio system designers are frustrated by performance differences between concept vehicles and production implementations. Reasons for differences include sealing issues, material changes, structure differences, etc. Even 1-2 dB differences in side to side acoustic balance can degrade spatial performance.

Strategies to address this issue include tightening specification, but this is unlikely to completely solve this problem. Post-manufacturing re-equalization could also help, if a good way to do this can be found. This issue was discussed in Munich.

20. Modern surround sound encoding algorithms use metadata to send 5.1 information in about the same bandwidth as stereo information. Offerings include Dolby Digital Plus, DTS Neural Surround and MPEG Surround (MPEG-2 TS. I think), This could kindle more interest in surround sound. One hopes that surround offerings become somewhat standardized, but production standards may not exist.

Meeting Report:

These documents do not necessarily express the official position of the AES on the issues discussed at these meetings, and only represent the views of committee members participating in the discussion. Any unauthorized use of these publications is prohibited. Authorization must be obtained from the Executive Director of the AES: Email, Tel: +1 212 661 8528, Address: 551 Fifth Ave., Suite 1225, New York, New York 10176, USA.

2005-5-23     Meeting Minutes AATC 117th
Description: Technical Committee Meeting on Automotive Audio 28 Oct 2004

2004-6-22     Minutes of Automotive Audio TC, 116th
Description: This document contains minutes of the Automotive Audio Technical Committee meeting at the 116th Convention in Berlin.

2004-4-17     Minutes of Automotive Audio TC, 115th
Description: Minutes of the 115th Automotive Audio Technical Committee in New York

Committee Members

Allan Phillips	Angelo Farina	Arndt Hensgens
Dave Baehr	David Clark	David Dage
David Navone	Earl Geddes	Eric Benjamin
Floyd Toole	Garry Feeley	Jayant Datta
Jim Hunter	Jim Stratman	John Busenitz
John Stewart	Jyri Huopaniemi	Karlheinz Brandenburg
Mark Ziemba	Marshall Buck	Mike Harris
Peter Mapp	Richard S Stroud	Richard Small
Robert Franks	Robert Schulein	Ryan Mihelich
Scott Orth	Sean Olive	Soren Bech
Spiro Iraclianos	Stan Smith	Steve Hutt
Thomas Sporer	Tim Nind	Tom Heed
Tom Nousaine	W.A. Deutsch	Kenneth Deetz
Kevin Heber	Stel Anthony	Wolfram Jaehn
Jonathan Lane	Tim Richardson	Steve Hoshaw
K. C. Furge	Alan Trevena	Nigel Fletcher
Siegmund Schreiber	Timo Esser	Bradley Eid
Hebert Etzel	Wolfgang Klippel	Tyrone Hunter
Edgar Kirk	Brian Sterling	Michael Noll
Brent Karley	Wontak Kim	Doug Hunley
Raymond Seymour	Mark Kalman	Lin Lin
Joe D'Angelo	Martin Lindsay	Viv Railton
Dave Wilson	Tom Breithaupt	Hans-Juergen Nitzpon
William L Martens	Natanya Ford	Rafael Kassier
Kim Rishoej	Matthias von Saint-George	Gerhard Pfaffinger
David Carlstrom	Matthew Watson	Bernard Fox
Varuni Witana	Josh King	Laurie Fincham
Jean-Philippe Dupire	Phil Muzio	Robert Sloan
Todd Welti	Phil Simpkins	John Yungman
Jason Kemmerer	Brett Hanes	Timothy Jackson
Jeff Koch	Steve Swanson	Todd Rockwell
Michael Truman	Jay Krusac	Reinhard Gretzki
Brian Knauss	Philipp Krejci	Ruediger Fleischer
Kristina Busenitz	Phil May	Tom Conlin
Glenn Cass	Richard Clark	Roy Delgado
Jon Zenor	Roger Kessler	Ken Kantor
Mae Nutley	Morten Lydolf	Armin Hoh
Jonathan Pierce	Andreas Suess	Vitor Soares
Roger Shively	Peter Perzlmaier	Volker Hochwald
Markus Christoph	Niyati Desai	Ed Maniet
Kelvin Griffiths	Thomas Gmeiner	Marcus Koch
Sergio Liberman	Christopher Matthews	Sean Thomson
Christophe Macours	Jeff Bailey	Rob Barnicoat
Toby Newman	Tyler Walker	Robert Hewitt
Wolfgang Hess	Guy A. Torio	Hans Lahti
Michael Cozza	Armin Prommersberger	Michael Strauss
Shinichi Sato	Stefan Holzhäuser	Arnold Knott
Tadeo Spraggon-Hernandez	Jurgen Gach	Christian Schmidberger
Chen Chienhao	Tom Ammermann	George Weaver
Peter Primo	Leonard Kreitmeier	Hans Juergen Regl
Adrian Cartllidge	Matt Jones	Robert Klacza
Krestian Pedersen	Marco Castro	Matt Ruhlen
Steffen Bergweiler	Shinji Koyano	Barry Moskowitz
Pat Dennis	Carsten Schulz	Andreas Fritsch
Benedetto Altieri	Michael Adenauer	Piergiovanni Bazzana
Tobias Warmbrunn	Christian Tasch	Thomas Beer
Imre Csonka	Dirk Thomschke	Christopher Herold
Stefan Behr	Ronald Schulz	Paul Beckmann
john Feng	Alfred Svobodnik	Kevin Bastyr
Rifky Cahyadi	Jan Pedersen	Toni Treichel
Deersheet Mehta	Luke Blaszczynski	Neil Pedinoff
Tom Morrow	Soonkwon Paik	Sachin Karajagi
Frederico Conte	Juliano Medeiros	Nazrizal A. Tajuddin
Seno Adi Wibowo	Fré Jorritsma	Emanuele Ugolotti
Gregory Sikora	Toy Zhang	Jakub Honkisz
Martin Berg	Thomas Guignard	Oliver Alic
Kai Inha	Patrick James Hegarty	Simon Woolard
Lena Schell-Majoor	Florian Rill	Stefan Varga
Thomas Bachmann	Jeff Tackett	Sandra Brix
Robert Hartman	Patrick Putzolu

To request membership in this Technical Committee please email the Chair by using the link above.