I have posted the same question on Apple discussion forum, but no one answered it, so I decided to post it here again. Please take time to help me out thanks! I have MBP 2.2Ghz I've noticed that there are imbalances between left and right speakers. When the sound balance is set to center in sound preference, everything sounds fine. When I adjust the sound balance to left speaker, I can clearly notice that it lacks bass sound, but it's extremely good with high. It has really clear/sharp sound. Vocal sound is very noticeable as well. Cymbal is also extremely noticeable than the right speaker. When I adjust the sound balance to right speaker, I can noticed that it has much more bass sound than left speaker. The sound comes out muddier than left. Also, on the right side of the palm rest I can feel the bass vibration, while there's no vibrations at all on the left palm rest. Also, the other day when I was on Youtube listening to linkin park's song, I've come to notice that the left speaker has noticeable clipping/hissing sound when the sound loudness is half way and up. I switch to iTunes and listen to the songs again, the speaker is fine, no clipping/hissing whatsoever. I noticed that the video made by linkinparktv all have the similar problem, but when I switch to other users' linkin park video they don't seem to have this problem. Is that due to the low quality video that linkinparktv posted, or is that really my internal speakers' problem. I'm really ocd about these sorts of things, and in fact they are driving me crazy. I just want to confirm if anyone else has the similar issue, or it's my hardware problem. I don't want to take back to Apple and go through all the trouble of switching speakers and end up the same result. Thanks again for reading this long comment.