Re: [gentoo-user] Switch between sound cards?

[Mark Knecht]

On Sun, Feb 24, 2008 at 3:21 PM, Grant <emailgrant@×××××.com> wrote:
> > Grant,
>  >    If you want to do a complete switch then you would change your USB
>  >  card to index 0 and restart Als which would make the USB card the
>  >  default since card 0 is always the default for Alsa. On the other
>  >  hand, if you wanted to just leave the onboard card as default and send
>  >  audio from a specific application to the USB card you would tell the
>  >  application to use hw:1 explicity, either in the command line when you
>  >  start the app or in an application's config file. On my system I let
>  >  all my web/browest audio go to the onboard sound card but I send all
>  >  my CD audio directly to my good card using Aqualung and configuring it
>  >  from the command line. (Actually in my launcher.)
>  >
>  >    to the best of my knowledge there has never been a way to simply
>  >  switch sound cards on the fly in Alsa. I've requested this sometime
>  >  back but the developers haven't shown any interest.
>  >
>  >  Hope this helps,
>  >  Mark
>
>  Hi Mark,
>
>  Changing the index and restarting alsasound would be a great switching
>  method but I can't get that to work.  No matter which one I set to
>  index=0 and which to index=1 the sound always comes out of the USB
>  card.
>
>  BTW, what sound card are you using?  Here's mine, it's great:
>
>  http://diyparadise.com/shop/index.php?main_page=product_info&cPath=2&products_id=82
>
>  - Grant
>
>
>
>
>  >  > >  > I have a USB sound card and an internal sound card in my laptop.  Is
>  >  >  >  >  there a way to switch between them while the system is booted?  Is
>  >  >  >  >  module loading/unloading via modprobe the best way to do it?
>  >  >  >  >
>  >  >  >  >  - Grant
>  >  >  >  >  --

Grant,
   On the previous machine where I gave you the modules.d/alsa file I
use the onboard sound chip for most sound but my main card is a 26
input, 26 output RME HDSP 9652 card.

   On my wife's machine, and out MythTV backend server, we use the
intel-hda oinboard sound chip for most audio but we also have an
external usb sound card that converts from USB to TOS link which I use
to drive our home theater receiver. I'm putting the alsa file at the
end of this post.

   Note that on this machine when we want to play audio using Aqualung
through the onboard device this is the command in the Gnome launcher:

/usr/bin/aqualung -o alsa -d hw:0,0

while if we want to play through the USB device we use this:

/usr/bin/aqualung -o alsa -d hw:1,0

Not sure why you'd be having trouble. We use this technique on
Aqualung, mplayer, xine and MythTV. The basic idea works once you get
it under control.

Good luck,
Mark

mark@dragonfly ~ $ cat /etc/modules.d/alsa
# Alsa 0.9.X kernel modules' configuration file.
# $Header: /var/cvsroot/gentoo-x86/media-sound/alsa-utils/files/alsa-modules.conf-rc,v
1.4 2004/11/16 01:31:22 eradicator Exp $

# ALSA portion
alias char-major-116 snd
# OSS/Free portion
alias char-major-14 soundcore

##
## IMPORTANT:
## You need to customise this section for your specific sound card(s)
## and then run `update-modules' command.
## Read alsa-driver's INSTALL file in /usr/share/doc for more info.
##
##  ALSA portion
alias snd-card-0 snd-intel8x0
options snd-intel8x0 index=0

alias snd-card-1 snd-usb-audio
options snd-usb-audio index=1

##  OSS/Free portion
alias sound-slot-0 snd-card-0
alias sound-slot-1 snd-card-1
##

# OSS/Free portion - card #1
alias sound-service-0-0 snd-mixer-oss
alias sound-service-0-1 snd-seq-oss
alias sound-service-0-3 snd-pcm-oss
alias sound-service-0-8 snd-seq-oss
alias sound-service-0-12 snd-pcm-oss
##  OSS/Free portion - card #2
alias sound-service-1-0 snd-mixer-oss
alias sound-service-1-3 snd-pcm-oss
alias sound-service-1-12 snd-pcm-oss

alias /dev/mixer snd-mixer-oss
alias /dev/dsp snd-pcm-oss
alias /dev/midi snd-seq-oss

# Set this to the correct number of cards.
options snd cards_limit=2
mark@dragonfly ~ $
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