This page is now largely redundant, as hardware and software technology has progressively embraced multi-channel audio.

There may still be issues with some legacy software, e.g. old Linux applications that have never been updated e.g. to use libsndfile.

I have kept it active as the soundfile examples are still of use.

Last modified: 7th November 2016

What can I do with a multi-channel device?

• play a m/c file (WAVE, AIFF, etc) with MediaPlayer (or equivalent system-provided program), locally, or from a network
• get guaranteed synchronization - vital for panning, ambience, matrix-encoded audio, etc
• save a m/c mix directly to a CD-ROM as a WAVE file, and play it back (cheaper than ADAT!)
• play them on other platforms, such as Linux, or even the Mac
• perform direct sound synthesis, reverb, spatialization and other effects over all available channels (with appropriate software!). It is MUCH easier for an application to write to one device, than to  several  (hopefully synchronised!).
• demonstrate surround-sound audio from CD  without any special hardware or software beyond the m/c card.

A paper (Word 97 format)  by Dave Rossum (Creative Labs), 'An Integrated Approach to Multi-Channel Audio', presented at WinHEC 99, is well worth reading, for a broad perspective on the many multi-channel paradigms, argued from the perspective of a 'virtual' recording studio, as might be implemented in a modern Audio Workstation. It includes a reference to the new WAVE-FORMAT-EXTENSIBLE ('WAVE_EX') multi-channel file format, which is supported in Windows2000, and also in Windows98 Second Edition, recently announced.

All the floatsam and 16bit soundfiles (except the first two, which are kept as 'minimum-header' examples, but including the Michael McNabb examples) contain the newly defined PEAK chunk. This gives information on the position and amplitude of the absolute peak sample in each channel (in the range  +- 1.0). It can be used for all WAVE, AIFF (including AIF-C), and WAVE_EX  formats. As the PEAK chunk is 64bit aligned, it is fairly future-proof (it could be used in a SDIF file, for example). However, to allow for later enhancements, it includes a version field. This is version 1. Detailed information for programmers can be found at Tom Erbe's website. The PEAK chunk is supported in the CDP Multi-Channel Toolkit.

Test WAVE files.

Mono and stereo files:

Soundfile 1:  a basic minimum-header standard mono WAVE file.  Should be safe.
 22050Hz, 16bit, 2.58 secs, 113,748bytes.
Zipfile    99,216 bytes

Soundfile 2: the same, except in TYPE-3 32bit floats.
22050Hz,  16bit, 2.58 secs, 32bit floats, 227,452 bytes
Zipfile   209,316 bytes

Soundfile 3: a standard 16bit stereo WAVE file, but with a long header. Should be safe.
22050hz, 16bit, 1.32 secs, 118,168 bytes
Zipfile   79,796 bytes

Soundfile 4: the same, but in TYPE-3 32bit floats.
22050hz, 32bit floats, 1.32 secs, 234,246 bytes
Zipfile   99,914 bytes

Soundfile 5:  a basic enveloped sinewave, 440 Hz, TYPE-3 floats
44100 Hz, 32bits,1.85 secs, 328,458 bytes.
Zipfile 299,546 bytes

Soundfile 6:  a minimum-header mono 24bit WAVE file.
22050hz, 24bit PCM, 2 secs, 131,682 bytes (created with Cool Edit Pro)
Zipfile   112,303 bytes
 

An AIFF-C Example:

Soundfile 7: same as Soundfile 4, but PEAK chunk only
Zip File (95K)
(NB: the Quicktime plugin seems not to like this file!)
 

Multi-channel files (all with long header) (created with CDP):

Soundfile 8: a quad (4-channel) file. Three channels have boring sounds.
22050Hz, 16bit, 1.98 secs, 352,288 bytes
Zipfile   165,108 bytes

Soundfile 9: a six-channel file. A mono sound, reverberated into 6 channels.
(The direct sound is written to channels 1 and 2 only)
22050Hz, 16bit, 2.36 secs, 626,812 bytes
Zipfile   351,869 bytes
 

Soundcards.

All modern soundcards now support multi-channel audio. Even purely stereo ones may offer support for Dolby 5.1 streams.
 

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