using two sounddevices?

Richard Dobson rwd at
Mon Dec 6 23:27:46 CET 1999

Yes, syncing separate soundcards is pretty well impossible unless one of
them can be slaved to the word clock of the other (as some cards do
offer, indeed).

However, the best solution for this task is a true multi-channel card,
such as the Sonorus STUDI/O, which can be addressed as, for example, one
eight-channel device. The Sonorus does have Linux support, including the
8-channel mode (through the ADAT lightpipe, so you would need a
converter). There are several such cards
available for Windows, of course (see my Soundcard Attrition Page for
details - URL below).

The consequence of this is that only one device needs to be opened; you
would then write a quad stream just as easily as one writes a stereo
one. Needless to say, support for such a device would need to be
incorporated into the PD code. It's on my list of "things I want to do"
for PD under Windows - in my case, driving the Creamware Pulsar running
its '16-channel Interleaved' mode. Creamware are promising Linux support
sometime, but certainly not soon, and Very Unlikely to be Open Source. 

Richard Dobson

Karl MacMillan wrote:
> Marius
> I think that there are some sync issues when using two sound cards in
> this way that may only show up when trying to do real time processing
> like PD.  As far as I know there is no provision for this in PD at the
> moment but I have written the beginnings of this into the ALSA driver
> code that is in the latest release.  One of the questions is how to
> specify which devices to open on the command line.  Any thoughts
> anyone?  The -soundoutdev and -soundindev only apply to the RME
> Hammerfall card.
> Karl
> s_medge wrote:
> >
> > hi,
> >
> > some programs (w95) can handle two soundcards simultanously. i actually
> > run pd with different devices for soundin and soundout. (no full duplex
> > cards). my question is, if it would be possible to use both sounddevices
> > for output (four channels)? is there an argument like soundoutdev 1+2???
> >
> > marius.

Test your DAW with my Soundcard Attrition Page! (LU: 17th September 1999)
CDP: (LU: 4th November 1999)

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