Make alsa default to usb sound device
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Joined: 26 Sep 2003
Posts: 3969
Location: East Coast, West Coast? I know it's one of them.
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As we all will find, pieces of our laptops die. For me, it was the motherboard sound chip. Sadly, as it died, alsa decided my new default was the modem sound device.

But my new default was actually a nice cheap little usb sound device, by (works fine in Linux out of the box by the way)

I found some typically convoluted ideas online about how to fix it, but the final result was a very simple tweak to the file:

/etc/modprobe.d/alsa-base.conf (this is a Debian system, your file name may vary)

:: Code ::
# autoloader aliases
install sound-slot-0 /sbin/modprobe snd-card-0
install sound-slot-1 /sbin/modprobe snd-card-1
install sound-slot-2 /sbin/modprobe snd-card-2
install sound-slot-3 /sbin/modprobe snd-card-3
install sound-slot-4 /sbin/modprobe snd-card-4
install sound-slot-5 /sbin/modprobe snd-card-5
install sound-slot-6 /sbin/modprobe snd-card-6
install sound-slot-7 /sbin/modprobe snd-card-7
# Cause optional modules to be loaded above generic modules
install snd /sbin/modprobe --ignore-install snd && { /sbin/modprobe --quiet snd-ioctl32 ; /sbin/modprobe --quiet snd-seq ; }
install snd-rawmidi /sbin/modprobe --ignore-install snd-rawmidi && { /sbin/modprobe --quiet snd-seq-midi ; : ; }
install snd-emu10k1 /sbin/modprobe --ignore-install snd-emu10k1 && { /sbin/modprobe --quiet snd-emu10k1-synth ; : ; }

# Prevent abnormal drivers from grabbing index 0
options bt87x index=-2
options cx88_alsa index=-2
options snd-atiixp-modem index=-2
options snd-intel8x0m index=-2
options snd-via82xx-modem index=-2
# Keep snd-pcsp from beeing loaded as first soundcard
options snd-pcsp index=-2
# Keep snd-usb-audio from beeing loaded as first soundcard
options snd-usb-audio index=0
options snd-card-0 index=5
options snd-card-1 index=6

All I did was uncomment the item, and change -2 to 0:
options snd-usb-audio index=-2

then I added the two other sound devices alsa could find, and give them an index number higher than the usb audio device.

options snd-card-0 index=5
options snd-card-1 index=6

This took some trial and error, but all the more complicated methods were totally pointless, didn't work, and didn't achieve the simple aim of making the usb device the default one, which is necessary for firefox flash sound to work (firefox always uses index=0 device, but if you haven't explicitly alsa listed your other sound devices, just setting usb sound index to 0 does NOT work.

I figured out how to do this using some reasonably helpful examples from
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Status: Assistant
Joined: 21 Sep 2008
Posts: 358
Location: Australia
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your link might be

hubi created a far better IMHO config file as

:: Quote ::
The content of /etc/asound.conf would be:

options snd-usb-audio index=0

options snd-hda-intel index=1

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