Hi all,

in my PC (which runs Sidux Linux, a fork of Debian Unstable) I have 2 soundcards active, an ALC850 on board (featuring VIA 8237 chipset and via82xx ALSA AC97 drivers) and a Soundblaster Live 5.1 PCI (with emu10k1 chipset and same ALSA driver). You can see it yourself here:

**** List of PLAYBACK Hardware Devices ****
card 0: Live [SB Live 5.1], device 0: emu10k1 [ADC Capture/Standard PCM Playback]
Subdevices: 32/32
Subdevice #0: subdevice #0
Subdevice #1: subdevice #1
Subdevice #2: subdevice #2
Subdevice #3: subdevice #3
Subdevice #4: subdevice #4
Subdevice #5: subdevice #5
Subdevice #6: subdevice #6
Subdevice #7: subdevice #7
Subdevice #8: subdevice #8
Subdevice #9: subdevice #9
Subdevice #10: subdevice #10
Subdevice #11: subdevice #11
Subdevice #12: subdevice #12
Subdevice #13: subdevice #13
Subdevice #14: subdevice #14
Subdevice #15: subdevice #15
Subdevice #16: subdevice #16
Subdevice #17: subdevice #17
Subdevice #18: subdevice #18
Subdevice #19: subdevice #19
Subdevice #20: subdevice #20
Subdevice #21: subdevice #21
Subdevice #22: subdevice #22
Subdevice #23: subdevice #23
Subdevice #24: subdevice #24
Subdevice #25: subdevice #25
Subdevice #26: subdevice #26
Subdevice #27: subdevice #27
Subdevice #28: subdevice #28
Subdevice #29: subdevice #29
Subdevice #30: subdevice #30
Subdevice #31: subdevice #31
card 0: Live [SB Live 5.1], device 2: emu10k1 efx [Multichannel Capture/PT Playback]
Subdevices: 8/8
Subdevice #0: subdevice #0
Subdevice #1: subdevice #1
Subdevice #2: subdevice #2
Subdevice #3: subdevice #3
Subdevice #4: subdevice #4
Subdevice #5: subdevice #5
Subdevice #6: subdevice #6
Subdevice #7: subdevice #7
card 0: Live [SB Live 5.1], device 3: emu10k1 [Multichannel Playback]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: V8237 [VIA 8237], device 0: VIA 8237 [VIA 8237]
Subdevices: 4/4
Subdevice #0: subdevice #0
Subdevice #1: subdevice #1
Subdevice #2: subdevice #2
Subdevice #3: subdevice #3
card 1: V8237 [VIA 8237], device 1: VIA 8237 [VIA 8237]
Subdevices: 1/1
Subdevice #0: subdevice #0

Currently ALSA identifies the SBLive as hw:0 and the VIA as hw:1. This is fine and how is my ~/.asoundrc file:

# Soundblaster Live 5.1
pcm.emu10k1 { type hw card 0 }
ctl.emu10k1 { type hw card 0 }

# ALC850 onboard
pcm.via82xx { type hw card 1 }
ctl.via82xx { type hw card 1 }

NOW, I understood, from endless browsing of ALSA and ALSA Wiki pages that, in order to make the two soundcards play together the same input (e.g. music from xmms), I have to create a virtual device in .asoundrc which enables ALSA to do so. *Unfortunately* there's no indication on how to do so on the whole internet!!!! And this seems to me something that every owner of multiple soundcard would like to be enable to do!

So, the *question* is: is there anybody here who can suggest me how to tune the .asoundrc file in order to obtain this multisoundcard virtual device?

Thanks a lot in advance!

i wouldn't go as far as to say that the whole internet.

http://www.alsa-project.org/alsa-doc...c.php#virmulti

i did this long ago when there wasnt such thing as 4 independant channel sound cards where nowhere to be seen.


Theres no reason you cant change the config from 4 unique channels to 2x2 matching channels

Hi carl0ski,

first, thanks for your quick reply. I had already hit on that page but that config is confusing to me , even because I don't need a virtual 4 channels card out of 2 different ones.

More, while for one card (the sblive that I use with skype) a reduction to 2 channels could be acceptable (even if I'd like to preserve it's digital output for future needs), I use the other one (the via ALC850) through S/PDIF with IEC958 on to feed directly digital output to my external Onkyo amplifier.

So the point is just about making the two soundcards play simultaneously the same stuff without any modification of channels whatsoever , i.e. with their full characteristics. From an IT viewpoint this shouldn't be complicated, it must be only matter of right config.

So do you think that it would be possible (and how?) to modify that script in order to get this result with a proper virtual device or how should I do?

Thanks a lot