I've ran into a pretty terrible issue and believe the cause is Windows 7 itself. I've checked through just about every site and thread looking for a good fix on this and there doesn't appear to be any.
I am working with:
Windows 7 Ultimate x64 OS
Auzentech X-Fi Forte 7.1 sound card
Logitech Z-5300 5.1 speakers/analog connection
The issue is that 'true' 5.1 sound will not play through all of the speakers of my 5.1 setup. Only certain speakers get used, depending on how I have them hooked up to the Forte. Basically it's only using 2.1 rather than 5.1. When I first installed my Forte, I was having no issues until I installed a few Windows Updates - after I restarted, 3 speakers were not working. No issues through Headphones, those work and sound great.
I am using MediaMonkey and WMP as my main test programs, as they used to work before without issue so I see no reason not to. Playing high quality MP3s'. Games and DVD movies work through all 5 speakers, but that's about it. The speaker test in the control panel has all speakers giving the properly sound locations and all speakers respond correctly when I hit 'Test'. That's the thing that really gets me.
I've done A LOT of troubleshooting, here's what I've tried to basically limit it to being a Win 7 jack assignment/configuration issue:
1) Checked connections on back of the card and speakers several times.
2) Reinstalled sound card drivers several times/played with settings in control panel/device manager.
3) Re-inserted sound card a few times.
4) Installed my old Creative SB Audigy card and hooked it up. Ran into the exact same issue.
5) Re-formatted entire PC - installed sound card drivers - same issue.
6) Everything IS configured properly.
What the ____ can you do more than that?! I went to the extreme on this issue and even that didn't work. I'd say this basically limits it down to being something to do with Windows 7.
I can't figure out why it was working when I first installed my sound card, and for about 2 weeks after that it was fine. All of the sudden, they stop working. I can use CMSS in X-Fi(or Matrix Mode on the speakers) to run 5.1 'Stereo' sound - which is basically the sound of 2 speakers playing through 5. This is not the same as True 5.1 and the sound quality is terrible. Even running 2.1 is better than that, but I bought a 5.1 system so I could use it, not have it look pretty.
Here are some threads where other people have ran into the same issue, with no apparent resolution:
I'm just wondering what I could do next...why is this not resolved? I am almost 100% sure this is something to do with Windows 7. I will go to great lengths to prove that, even installing Windows XP as a test. Hasn't anyone tried to get Full 5.1 from their Z-5300's and Z-5500's etc...? I know it's just not me. Any advanced users out there have an idea? The basics aren't going to work on this issue.
Windows 7 does not convert or upmix stereo source material into 5.1 or 7.1. 5.1 and 7.1 source material will be rendered appropriately. If you need, please feel free to use your optical outout into a surround receiver capable of performing the upmix/conversion.