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:

Automotive Audio Conference in Munich

135th AES Convention in New York: Meeting of AES Technical Committee for Automotive Audio, Workshop on 3D applications for AA.

Planned Automotive Audio Conference for West Coast of US

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 offering 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.

2. 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.

3. SSD's will replace hard drives as preferred storage when cost permits. Which vehicles now have SSD's?

4. 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. This may be the most likely way cell phones will bring music to the car, not streaming signals from towers.

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 but falling. Current price is around $120/kg (China). With high neo prices, speaker customers need a strong set of specifications to insure that suppliers maintain 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. Download of MP3 files into vehicles by home-based r.f. links has been introduced.

10. HD radio components are now for sale. 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.

11. There are an increasing number of center speakers appearing in prestige class automotive system designs. Speakers have also appeared in the tops of front seats. "Surround sound" is becoming mandatory in high-end automotive systems even when source is limited to two-channel (via upmix algorithms). Some listeners sense that some surround systems provide limited envelopment on both stereo and much "surround" source material.

12. 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.

13. Voice recognition systems for telephone and navigation functions are becoming more sophisticated and enjoy wider application.

14. Automatic Equalization is being offered for audio system tuning. Use of such automatic systems can significantly speed the tuning process, but may not soon completely replace final tuning for on-road performance by trained listeners.

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

16. 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.

17. Switching audio is now commonly seen 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 all audio power output conditions.

19. 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.

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

21. 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.

22. 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.

23. 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: 60 East 42nd Street, Room 2520, New York, New York 10165-2520, 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
Dan Field	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	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	Sheila McFarland	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

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