Hi,
has anyone had any (successful!) experience using multiple soundcards in PD under OSX? I am trying to use several devices (I can see them using pd -listdev from the command line) by adding the command -audiodev 2,3,5 to the startup and I am only getting the first device.
Just to make things more complicated, the first two devices are Bluetooth headsets (both have been tested alone and work) and the third device is the virtual device Soundflower. I have tried to use Jack but the Jack manual explicitly says that Jack will only support one hardware device at a time!
Have I managed to corner myself into an impossible situation where the OSX version of Pd can only deal with one hardware device at a time, regardless of what it seems to be saying on the command line help? Or is there a way forward?
I hope someone can help,
cheers,
tim
----- Tim Boykett TIME'S UP::Research Department \ / Industriezeile 33b A-4020 Linz Austria X +43-732-787804(ph) +43-732-7878043(fx) / \ tim@timesup.org http://www.timesup.org
Hi Tim,
it's quite difficult to get any application to use multiple soundcards at the same time for output. Or to use multiple input devices as well. You can even choose a different device for input and output, that usually isn't an issue. The reason being that, even though the output devices might all run at the same sample rate, they have different timing crystals and they will eventually drift out of synch just enough that the application won't know what to do anymore and will crash. That's why JACK and most every other sound driver only support one interface at a time.
The only way this could really work is if the audio devices are hard-synced somehow. That means one is the Master and gives the sample timing to all the others. Expensive soundcards can do this via digital connections, but not normal laptop/bluetooth/etc chipsets. If you Google up "ALSA + el cheapo", you'll find some hacker-types that wanted to do this with Linux ALSA drivers and a bunch of $25 Soundblasters to make a budget multitrack system. The only way they succeeded was by removing the clock crystal from all the cards except one, and soldering connections from that crystal to all the others. An "el cheapo" solution, but not one that would work in your case with Bluetooth devices. Maybe this gives you ideas, maybe not...
best, d.
Ti Bo wrote:
Hi,
has anyone had any (successful!) experience using multiple soundcards in PD under OSX? I am trying to use several devices (I can see them using pd -listdev from the command line) by adding the command -audiodev 2,3,5 to the startup and I am only getting the first device.
Just to make things more complicated, the first two devices are Bluetooth headsets (both have been tested alone and work) and the third device is the virtual device Soundflower. I have tried to use Jack but the Jack manual explicitly says that Jack will only support one hardware device at a time!
Have I managed to corner myself into an impossible situation where the OSX version of Pd can only deal with one hardware device at a time, regardless of what it seems to be saying on the command line help? Or is there a way forward?
I hope someone can help,
cheers,
tim
----- Tim Boykett TIME'S UP::Research Department \ / Industriezeile 33b A-4020 Linz Austria X +43-732-787804(ph) +43-732-7878043(fx) / \ tim@timesup.org http://www.timesup.org
http://www.timesup.org/fieldresearch/setups/index.html
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derek holzer -
Ti Bo