Re: [Alsa-user] Multichannel sound ?

[Florian S. <mis...@gm...>]

On Wed,  2 Mar 2005 15:39:38 +0100
ro...@vo... wrote:

> Hi!
> 
> How does one use the extra channels on a six channel card ?
> I can only hear the 2 front speakers.
> 
> I remember on a es1370 card, that I had an extra /dev/dsp1 for the rear speaker
> pair, but with an on board VIA audio there is only one /dev/dsp.
> 
> I also tried playing a 6 channel sound file with sox, but still only the front
> speakers make sound.
> 
> Any clues ?
> 
> HW is VIA 8235 + Realtek ALC650
> kernel 2.6.8-debian
> driver is OSS via82xxxx ( I'm willing to switch to ALSA, but a quick look says
> it is the same there ).
> 
> Ideally I would want a second stereo /dev/dsp1, that would produce sound on the
> rear speakers.

Ok, when using ALSA you can use stuff like

aplay -D plug:front some_wav_file.wav

or

aplay -D plug:rear some_wav_file.wav

The latter should produce output on the rear speakers. I don't know how
to send sound explicitly to center/lfe (lfe is not really an independent
channel in surround afaik, as it's just a lowpassed version of the mix
of all the other speakers, no?)

Although the specifics depend on the card you have.

Try to play the 6 channel .wav file with 

aplay -D plug:surround51 some_6_channel_wav_file.wav

maybe it works.

Flo

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