A little sleuthing please, experts...
I'm back with my sound woes...
I use my system for two things; ppruning & media centre. Ppruning's ok...
It's an asus p5l-vm mobo, 2x500gb hdd's, 2gb ddr ram, an nvidia 8500gt gpu, two Hauppauge tv cards, a nova-t 500 & an hvr 1700.
Now up until 2 weeks ago, on Vista tv pack, I had perfect 5.1 surround sound. Then I started to experience ups & downs in the volume. This was with a Creative xfi extreme audio card, which I didn't much rate anyway. So I changed it for an xfi extreme music. All was well for a while, but now I have lost 5.1 on live tv only I.e. on Video & music, the sound is perfect, but on tv, it only comes out of the front two speakers.
I have tried all new drivers, uninstalled & reinstalled the software, cc cleaned the system, deleted all Creative folders & registry entries prior to reinstallation & as a last resort, rebuilt the system from scratch.
No joy. Then I cleaned out again & installed the extreme audio card. Same result. So now I'm thinking the odds of two cards being faulty across two builds & two os'es (it's 7 rc1 dual boot) are remote. So if I can discount the os & I can discount the cards, could this leave the mobo?
I've flashed the bios & run all manner of diagnostics from memtest to Belarc to asus pc probe & all reports are fine.
I've built systems for years & never had such an intractable problem. I'm sorry for the long post, but I'm running out of ideas & would welcome fresh eyes. Ta.