here is the advice on this Alsa "multiple sound devices" subject
http://www.linuxquestions.org/questions/linux-software-2/how-to-configure-flash-9-in-firefox-to-use-a-specific-alsa-device-629183/Basically, my laptop is like most laptops and contains an internal sound chip.
Like many other people, i don't want to use that internal chip because
i want to use an
external USB soundcard instead.
Firstly i checked the bios and there was no way to disable the internal
sound chip. Newer laptop BIOS settings may offer the ability to disable the
internal sound chip.
For similar tcl user situations, where people have "multiple sound devices" but only want to use ONE device with Alsa, then disabling the internal sound chip is the easiest way for most people to get alsa working with a single
external USB soundcard. They can disable the internal sound chip, thus, they typically no longer have "multiple sound devices" and so Alsa should have no trouble in finding the single
external USB soundcard.if, like me, you can't disable the laptops internal sound chip and yet
you still want to use an
external USB soundcard via Alsa, then you are in the territory of "multiple sound devices". Alsa is not very good at automatically setting up multiple sound devices. (You must do this manually)
1) i Worked with a virgin boot of TCL from CD disc. i Plugged in the USB soundcard "before" powering on the laptop and booting into tcl.
2) i Reached the tcl desktop and installed Alsa.tcz extension and Alsaplugins.tcz extension and Alsaconf.tcz extension and Alsamodules2.3.6.tcz extension.
3) i ran the terminal command below to show what sound devices tcl sees in my system....
aplay -l
which resulted in the output below...
tc@box:~$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: I440MX [Intel 440MX], device 0: Intel ICH [Intel 440MX]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: Modem [Intel 440MX Modem], device 0: Intel ICH - Modem [Intel 440MX Modem - Modem]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 2: Set [USB Headphone Set], device 0: USB Audio [USB Audio]
Subdevices: 1/1
Subdevice #0: subdevice #0
tc@box:~$
4) As you can see, tcl knows about 3 sound devices. The first 2 of those devices are the internal sound chip. Alsa and tcl, infact, see 2 devices corresponding to the internal sound chip because 1 of them is some modem
hardware.
The 3rd device, device number 2, is my
external USB soundcard.5) Sometimes you may not initially see the
external USB soundcard as listed. Different laptop BIOS chips behave in different ways and some
may give priority to usb devices first, over-riding internal sound chips.
(i am not 100 percent certain here)
6) Anyway, i now unplug the
external USB soundcard.7) i Run the following terminal command to start Alsa driver.
sudo /usr/local/etc/init.d/alsasound start
8. The step 7) results in the following output for me.... below
Starting sound driver: snd-intel8x0
Starting sound driver: snd-intel8x0m
tc@box:~$
9) As you can see in 8, alsa and tcl have not initialized the
external
USB soundcard because it's not plugged into the laptop. But Alsa has
initialzed the 2 internal laptop sound devices. (it appears so).
10) Now i run the command below....
$ sudo alsaconf
11) Then i step through the Automatic configuration windows of Alsaconf ignoring doing any configuring but just probing ISA cards (non available) so as to complete the script.
12) Now i run this terminal command below..... again.
$ aplay -l
13) The result of step 12) is NO sound devices are found. (see output below)
aplay: device_list:235: no soundcards found...
tc@box:~$
14) Now i plug in the external USB soundcard and run the same command
as in step 12) The USB soundcard is detected as the "only" sound device presented to Alsa.
**** List of PLAYBACK Hardware Devices ****
card 0: Set [USB Headphone Set], device 0: USB Audio [USB Audio]
Subdevices: 1/1
Subdevice #0: subdevice #0
tc@box:~$
15) Play some music with a musicplayer and test that Alsa is correctly
driving your
external USB soundcard.--------------------------------------------------------------------------------------
i intend to try the advice given in the link at the start of this message
just to see if it works. It's pretty easy to alter his situation for your own
sound devices situation ....and see if his ideas work.
thanks
V.