I bought the logitech x-540s that have 5.1 sound. They all work fine but I can't get true 5.1 sound. The only way to get to get all speakers to work is enable "speaker fill" in the realtek options or press the "matrix" button my sound control. This is not true 5.1 and the rear speakers sound terrible and I can barely hear them. I did not pay good money for a 5.1 system only to use it as a 2.1 with "simulated" 5.1 sound! Please help, I don't want to switch to linux or xp to get this working. Thanks.
Realtek HD onboard soundcard
Latest realtek drivers R 2.36
Windows 7 32 bit
x-540 5.1 system
Most likely your problem is the audio source is not a 5.1 source. So playing music which is stereo will not come out the rear speakers unless you use speaker fill to simulate it. But if you play a 5.1 capable game or watch 5.1 capable movies you will notice they function properly.