Using two Soundcards in Parallel (11 Channels needed)

Hello everybody,

Is there a way to use two soundcards at the same time using psychportaudio on Windows? For a study we would like to play back mono sound from 11 separate speakers and we would need very low latency.

The soundcards we are using are RME HDSP 9632 with AO4S-192 AIO extension boards, and they support 6 channels each. So to operate all of the speakers we would have to use both soundcards at the same time.

So far I only found information (and a demo) on setting up a virtual slave device on one master soundcard (that has enough channels), but is there a way to do the same connecting to two physical soundcards to get access to all available channels?

Should trivially work when opening the two soundcards as separate devices via PsychPortAudio(`Open`, deviceIndex, ...) specifying the correct deviceIndex parameters for the two separate cards. Atm. PsychPortAudio’s (PPA) compiled in limit is 1024 separate sound cards.

If it doesn’t work then that would be a MS-Windows or 3rd party software bug or limitation, not really a Psychtoolbox problem.

Ofc. audio timing will not be hardware synchronized between the audio channels of those two sound cards, and PPA will treat them separately. You’d need to use PPA’s timing mechanism to get them roughly into ~millisecond accurate sync. Or maybe those cards have some builtin functionality to hardware synchronize them and/or treat them as one virtual soundcard with more channels.

Thank you very much for your reply, that was really helpful!