Said it before, but Michael Jacksons "Man in the Mirror" is a great tweeter stress test. If you get buzz on that you know there is an issue.
Additionally, Radiohead's "Kid A" Album is full of tones are also good for sniffing out problems. The tracks "Kid A" and "Morning bell" are particularly good ones for this. This is a brutal album for poor speakers/systems to handle at louder volumes.
Troubleshoot the error by using an alternate player if possible. You can rule out the speakers or PS3 in one step that way. Still issue= speakers/AVR. No issue= PS3.
Are you sure you are not just clipping out the AVR? I know it's class D and all but 290W max power is suspect. Still not sure about the non-linear output of those Class D setups.
Good luck.
