controlling audio front and back ports

[kyuso]

My system:
Fedora 14 x86_64
kernel 2.6.35.9-64.fc14.x86_64
built-in audio ATI HDA-Intel SB in ASUS AM3VM2-HDMI MB
Two sets of speakers, one in back audio port (call it BS), one in front audio jack (call it FS)

My problem:
No sound from left of BS (BS_L), and no sound from right of FS (FS_R).
Only BS_R and FS_L have sound, and they are in stereo, so correct sound from the appropriate sides, but not in same pair.

Observation:
BIOS setting has front panel audio set as AC97, not HD-Audio. I tried both and no difference.

I tested both speakers in other PCs and other speakers on this PC, so no problem with speakers or wires.

I suspect some internal audio hardware mixer control needs setting. I tried pavucontrol, alsamixer -c 0, but none of them shows any way of controlling the front and back ports separately.

When selecting 'Analog headphone' from pavucontrol or gnome-volume-control, no sound comes out of either ports. Only 'Analog output' creates any sound.

So the question:

1. Is there a way to fix this using software?
2. Is my internal audio mixing circuitry broken?
3. Jack auto-detect not working (the manual says it can auto-detect what is being connected)?
4. Does the kernel not support this?

I don't use this PC often, and I only remember having it working in Fedora 11. Probably worked in Fedora 14 before, but not sure.

Another observation if that helps:
If I disconnect BS a little while, and reconnect, BS_L also has sound, although slitghty lower volume than BS_R. The moment I connect FS, or after a while, then BS_L goes out (there is a little very faint cracking as if trying to come out, but sound never materializes). The FS_L has no such short-term luck in any way.
No solution if I disconnect the internal wires from motherboard to front audio jack either.

[Tweedle]

PulseAudio is what's causing the problem. I have an ATI IXP onboard chipset that gives me a Radeon Xpress 200M/G and a Realtek -something or another- surround sound card. I have been testing out A LOT of linux distros just to find one that works correct and suites my needs. I've been through ubuntu, ubuntu studio w/ realtime kernel, openMamba 1.1 and 2, puredyne, 64studio, and a few others that gave me the same type of problems. Either no surround channels, or center/lfe, a bunch of interference, or completly wrong channels routed. EVERY single time I was to make any progress, it wasn't until after I set linux to use ALSA instead of Pulse, or complete disabled pulse (which was the best results)

This I'm working on right now in Fedora. From what I can tell, this is going to be the keeper for me. Not only is it running smoothly right after a fresh install (most distros don't run this well) but right off the bat pulse allowed me to hear my center channel and subwoofer. The weren't in the right place though (center came from rear left) So I am going to remove pulse, because it sux IMO, and go with straight alsa for now.

I have done this once before successfully in ubuntu, but that guided you towards OSS instead of alsa. But the basic principle is the same: kill pulseaudio with beaver's tail!!

I will start the process now, which is a little more than just removing pulse - don't do that! You have to disable it while keeping some basic stuff intact. I will post on my progress in a few and let you know how it's going in fedora

[kyuso]

Thank you for the info. I hate to do away with pulseaudio though. It's so promising and has worked fine so far, except for the wrong channels.

I guess I'll just listen to one speaker until it improves then.