I am not an audiophile, but I do get extremely annoyed by rattles, and resonance buzzing from things that shouldn't, like plastic speaker enclosures, etc. A few years ago I bought a Samsung TV which was a floor model,for two years it was hooked to a surround system. Then when we got another TV for the living room we rearranged the TVs and found out that the floor model had a rattle at certain frequencies. It is so annoying to watch a movie and hear this resonance rattling the plastic shroud at certain frequencies. I even went into the TV to try to tighten, glue, or remove whatever it was making the noise. In order to troubleshoot it, I had to be able to recreate it consistently, so that I could try different solutions. It was then that I developed this testing file with Cool Edit 96 (old version). I was able to estimate the frequency the rattle was coming from and made an additional single tone file for diagnostics. I never could find out how to fix it without making things worse. So I decided that in the future I would test the audio for any annoying resonance/rattling while still under warranty, preferably while still within the return period, and best of all before even leaving the store or offering to buy. The file I created is 10 Hz to 10000 Hz in 60 seconds with a constant rate of change. The audio does start right at the beginning of the video, but all people cant hear it and not all speakers will produce sound below their capability limits. Same goes for the high end. So if you hit resonance, just note how many seconds you are into the file. Then take (seconds*(10000-10)/60)+10=Frequency in Hz that your stuff resonates at. You may even get more than one or several due to frequency orders. For more on that refer to Wikipedia: Acoustic Resonance. Please use this file at your own risk.