Hey everybody. Currently the problem I am having with my sony sa-wm40 is that whenever it has to put very low bass, it seems to make an annoying noise like if something is buzzing. I had bought my sub. at Best Buy with a warranty about almost a year ago and had previously taken it to them twice to see if they could fix the problem, but they supposedly could not find a problem with the sub. The question is if this is something normal that the sub. does because it can't handle the low bass, or is something I could have caused by opening it too much when I was adding pollyfill and maybe the holes where the screws go through might have gotten looser. I'm sure it's not the polyfill inside because I had taken the polyfill out to see if it was the problem but it wasn't. I am also sure it is not the subwoofer because I had taken the sub. out and played a low tone to see if it was the problem, but it wasn't because it didn't make the buzzing noise. So what do you guys think might be the problem and do you think there is anything I can do to fix the problem. Any information will gladly be appreciated. Thanks.