[linux-audio-user] noisy capture->playback

David dplist at free.fr
Sun Nov 2 14:10:08 EST 2003


On Sun, 2 Nov 2003 13:18:12 -0500
Joe Hartley <jh at brainiac.com> wrote:

> On Sun, 2 Nov 2003 19:07:39 +0100
> David <dplist at free.fr> wrote:
> 
> > On 02 Nov 2003 09:48:44 -0600
> > Jan Depner <eviltwin69 at cableone.net> wrote:
> > 
> > > I'm not sure I'm following this.  How have you got envy24control
> > > set up?
> > 
> > Bad noise comes when I set H/W Out 1/2 to PCM Out 1/2 and connect
> > using jackd the alsa capture port (that map to a H/W In) to the alsa
> > playback port 1/2 (that maps to PCM Out 1/2).
> 
> David, how exactly dows this mapping take place?  Via a command line?
> A jack patchbay?  Routing in a particular program?  or with the
> envy24control GUI?  Detailing the steps you take to set this up may
> prove helpful.

By default, jackd maps its "alsa_pcm:capture_1" port to the "H/W In 1" 
input of the soundcard and its "alsa_pcm:playback_1" port to
the "PCM Out 1" of the soundcard.

I connected these two jack ports using qjackconnect, I guess I could do
the same with jack_connect. 

With envy24control's "Patchbay/Router", I chose "PCM Out 1" to be
heard on "H/W Out1" so that I can hear what jackd is spitting in 
"alsa_pcm:playback_1".

I this a little bit clearer ? Sorry for being confusing.

> I recall having this happen when I had the Omni (long since upgraded
> to a Delta 1010).  I think there was some sort of monitoring or source
> button I had to push on the Onmi box to stop this.  The noise, if it's
> what I'm thinking of, is the digital equivalent of a feedback loop.

On the Omni itself ? I don't think I have such a button.

> -- 
> ======================================================================
>        Joe Hartley - UNIX/network Consultant - jh at brainiac.com
> Without deviation from the norm, "progress" is not possible. - FZappa

Thanks.

-- 
David



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