[linux-audio-user] How can i set this up?

Mark Williams (MWP) mwp at internode.on.net
Tue Mar 16 10:11:53 EST 2004

> > Im still trying to work out how JACK works... the end-user docs for its
> > operation are almost non-existant. All i seem to find are devel docs and
> > simple
> > FAQ's like those on the JACK website.
> >
> > I dont have X installed, so all these nice X windows JACK utils are useless
> > to
> > me. And no... im not going to install X either.
> No problem here. Just use "jack_lsp" to list the available ports
> and "jack_connect portX portY" to create connections between ports
> rsp. "jack_disconnect portX portY" to delete them again. All these are
> command line programs. I use X, but I don't like graphical jack patchers
> generally either.

Ok, thanks, i know about jack_lsp and jack_connect & disconnect.
But i wasnt sure if there were other setup type utils i would miss by not
having X.

> > If im going to use JACK to tie all this together, my first problem is getting
> > it
> > working with a multichannel ALSA device.
> >
> > The output card is a Envy24HT... i have asound.conf setup for a PCM per
> > stereo
> > output (evny_1, envy_2, etc).
> >
> > How do i tie these channels together to make a single 10 channel device that
> > JACK can then output to?
> You probably don't need to fiddle with asoundrc at all. Just starting jack as
> $ jackd -d alsa -d hw:0
> should work. (Later you would do the the next steps, that include getting
> jackstart to work and using realtime mode.)
> It will simple use up all the in- and outchannels your card has to offer.
> "man jackd" will show you some more options to jackd, some of which will let
> you specify the number of channels to use or if do do playback only and such.

Ok... that was too simple :)
It picks up the 2 input channels and the 8 output channels.
Its missing the SPDIF output channels though, but im not sure if ill need to use
those as yet... so ill forget about it for the moment.

And after a bit of playing, ive got BruteFIR working correctly too using the

input "left-in", "right-in" {
        device: "jack" { ports: "", ""; };
        sample: "AUTO";
        channels: 2;

output "left-high-out", "right-high-out", "left-low-out", "right-low-out",
"sub-out" {
        device: "jack" {
                ports: "alsa_pcm:playback_1", "alsa_pcm:playback_2",
                        "alsa_pcm:playback_3", "alsa_pcm:playback_4",
        sample: "AUTO";
        channels: 5;

Thanks Frank, everyone!

More information about the Linux-audio-user mailing list