-> sound card for multiple cards

I’m setting up asterisk 1.4.4 with two soundcards, each hooked up to one overhead paging system. I have tied each to an extension for paging. I can get dsp (alsa card 0) working just fine, but can’t get dsp1 to output any sound.

In the /etc/asterisk/alsa.conf I see settings for input_device and output_device, but is there a way to specify 2 different cards?


Do you have to drive them from two different extensions? If not, a little wiring (and alsamixer) is much easier.

Can I get some more detail on what you are suggesting?

I do need some way to differenciate different zones, I have to plug in to two amps, one for one part of the building and another for the second.


Obviously your cards have line-out; they generally have line-in. What I’m thinking is to tap the line-out of card0 and connect to line-in of card1. In alsamixer, allow card1’s audio to pass from line-in directly to line-out. I assume you amplify from line-out, so the tapping require little consideration for balancing. If the cards do not have line-out, you can ask a good electronics store to help come up with a small balancer.

So card1 is just cascading signal to second amplifier. I’m not sure why is it necessary to use a second card to drive the second amplifier if the audio is going to be identical, but I’m almost certain whatever the concerns, a little electric circuit could address.

Thanks, that’s a solution. Not quite what I needed, but perhaps passable.

The audio on each line is separate, for different zones of the facility. I wanted them on different extensions. But if I can’t get that, I’ll have to settle for powering both amps (currently in place) on one extension. Your solution would let me do that.

Does anyone know how to use each soundcard for a separate extension?


I would simply set up another box with the second card as console.

does anybody know if there will be support for multiple alsa soundcards?