Support of input multi-channel audio file in Chrome/Firefox

Hi all,

I have some questions regarding the support of multi-channel audio files in Chrome and Firefox and I think that this might be the correct list to talk about them.
(This is my first post here, I am currently doing an internship at IRCAM [ http://www.ircam.fr ] working on audio spatialization client side using Web Audio API.)

My experiment:
I read a multichannel audio file with a BufferNode, then I split it with a SpliterNode, process and convert it into a stereo channel.
The problem is that even if the AudioBuffer returns the right numberOfChannels of my input file, some audio formats don't play well.

I have been searching for web pages about supported multi-channel formats on each Web Audio API browser implementation but I didn't found it.
I found the media formats supported by Firefox and Chrome that specify what are the supported audio files [1] [2] but these explanations don't correspond with the multi-channel files.

I have been testing with a 5-channel wav file in Chrome and it works correctly. When I test it in Firefox, it doesn't work correctly, it sounds like a kind of noise.
I tested a 5-channel ogg file and it works fine in Firefox but not perfect in Chrome. I'm using Mac OS X.
Do you have some information regarding the supported and unsupported file formats for multichannel ?

Thank you,

[1] https://developer.mozilla.org/en-US/docs/HTML/Supported_media_formats
[2] http://www.chromium.org/audio-video