Re: Setting sound card for full duplex

I have been unable to find out if my card supports
full duplex. Assuming that it does, how do I set
it for full duplex?

If you're using alsa drivers.

cat /proc/asound/devices

It should by default. Software for full duplex recording
on the otherhand might be difficult. Most sound cards,
even el cheapo integrated ones have at least two input
channels and two output channels. Granted that that's
just stereo capabilities, stereo in, stereo out.


For me, I have a few options.

-----

jackd + ardour

jackd -d alsa -d hw:0 -S -s -r 48000
&&
ardour

(ardour can be a little difficult to use.)

-----

jackd + audacity

jackd -d alsa -d hw:0,0 -S -s -r 48000
&&
audacity

(however there's some bugs in audacity.)
- without jackd, the recording sounds like
things went through a metalic filter.
- with jackd, after the first playback it
will no longer playback. At least not
with sound coming out the speakers.

-----

Now there's some issues with regards to
mixer settings that makes things either
work or not. i.e. for the above apps you
need to set your record device to the
microphone. And push the setting for the
mic and gain to about 70% in my case.

aumix -m R -m 70 -i 70

-----

Now if you want to capture your /dev/dsp
output, there's a different quirk.

aumix -v R -i 1
&&
arecord -t wav -f dat -D default test.wav

(aka set your record device to master volume
and gain to 1)

-----

At least this is what's worked for me.
Mileage may vary.

Almost all of the above assume you're not running
a sound mixing daemon like artsd or esd. Since
jackd is one of those daemons. If you are, you're
sound device will appear to already be in use by
anything that doesn't use that method for generating
sound. The end result of which is most times NO SOUND.

Shadow_7

.

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