PS3 Possible Audio Problem + Center Speaker Audio

[School]

Ok im going to try to explain this as best as possible. I have recently noticed that there is some type of static noice that comes through my front speakers while playing certain PS3 games. My receiver is set to multi channel in for most games and for rythem type games its set to 5 channel audio. I also notice that when i play rockband that when i use the wammy bar on long notes i notice that the audio also makes a static like noise. Now for blu ray movies the only audio problem i have is that my center channel speaker is kind of low, i do listen to my movies very loud but i do find the voice audio a bit hard to hear. Im just looking to see if anyone knows how i can fix these problems or if its a problem with my equiptment?

Thanks for looking