configuring speakers for 4.1 channel output on x86, ALSA machine with VT8237
 

hello friends,

I am having an intel machine with linux' redhat 5.4 distro. It's superb when it comes to server making and other admin. kind of stuffs but it fails when it comes to multimedia for i am unable to configure the sound file (asound.rc), i tried various codes but it only gives sound output on 2 front speakers. i want to activate other two rear speakers and the center one as well. this is my card info
Multimedia audio controller: VIA Technologies, Inc. VT8237 AC97 Audio Controller

this is what my sound files have
------- /etc/asound.conf --------
#Generated by system-config-soundcard, do not edit by hand
#SWCONF
#DEV 0
defaults.pcm.card 1
defaults.pcm.device 0
defaults.ctl.card 1
pcm.51to41
{
type route
slave.pcm surround41
slave.channels 4

# Front and rear, at 50% of original signal strength
ttable.0.0 0.5
ttable.1.1 0.5
ttable.2.2 0.5
ttable.3.3 0.5

# Center channel routing (routed to front-left and front-right),
# 6dB gaindrop (gain half of main channels) per channel
ttable.4.0 0.25
ttable.4.1 0.25

# LFE channel routing (routed to front-left and front-right),


------- aplay -l --------
**** List of PLAYBACK Hardware Devices ****
card 0: V8237 [VIA 8237], device 0: VIA 8237 [VIA 8237]
Subdevices: 4/4
Subdevice #0: subdevice #0
Subdevice #1: subdevice #1
Subdevice #2: subdevice #2
Subdevice #3: subdevice #3
card 0: V8237 [VIA 8237], device 1: VIA 8237 [VIA 8237]
Subdevices: 1/1
Subdevice #0: subdevice #0

------- amixer --------


------- /proc/asound/version --------
Advanced Linux Sound Architecture Driver Version 1.0.23.
Compiled on Dec 26 2010 for kernel 2.6.18-164.el5 (SMP).

------- rpm -q alsa-lib --------
alsa-lib-1.0.17-1.el5

------- rpm -q alsa-utils --------
alsa-utils-1.0.17-1.el5

------- /proc/asound/modules --------
0 snd_via82xx

------- /proc/asound/pcm --------
00-00: VIA 8237 : VIA 8237 : playback 4 : capture 1
00-01: VIA 8237 : VIA 8237 : playback 1 : capture 1


the sound quality is also poor.
please show me some way!

I am not a guru with sound devices, however, on my machine it seems like the PCM volume switch controls the volume of the rear speakers. I have had lots of interesting results in regards to sound across the different type of linux out there. Maybe try disabling the default ESD daemon that is used by gnome and use only ALSA, this actually worked before in my case as the daemons created lots of sound latency.