The buzz you hear is from the snares on the bottom hitting the bottom head. Sometimes when you tune up drums, i.e. higher tuning, the relative pitch to what they are tuned will react with the snare strands on the bottom of the snare. Don't worry, try tuning it a couple of cents flatter. (make it a tiny bit lower in pitch) Drums are not the only istruments that have this problem. In the winter, the Steinway piano up at the piano studio at school gets a louder, resounding tone on Gb. It just bounces all around the room. And in the Summer, Gb stops and Ab starts. It's the craziest thing, but I know it's because the wood in the piano breathes with the changes of seasons. If tuning your toms just a tiny bit lower doesn't help, try a couple of cents sharper. (tune them a little bit higher) What's more than likely happened is that your tom is tuned to a relative pitch to your snare and the sound waves become stronger when that happens, so the snare strands on your snare buzz in conjuction with the stronger sound waves. It's just a property of sound. Ever heard that a band sounds louder when everything is in tune? That's the same property.
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