I have had some experience with Rythmik subs but not for a formal review. They are good subs, but they aren't really that much better than these other brands that you mention. All of these subs have very good bass for music. You would never know the difference between them until you hit the subs' limits, and anyone who tells you otherwise is kidding themselves. The sound quality is determined by the frequency response, and the frequency response is governed by the room far more than the subwoofer. If you were really interested in having high-quality bass, you would be looking at something like a four-sub system with something like Dirac Bass Control. The brand of the sub hardly matters so long as it's not a really crappy sub.