Since there is an actual comparison going on between the SVS and Rythmik subs I am really interested in the impressions that come for some quality listening time. I bought the SVS SB13 Ultra right after they hit the market. All I can say is that I am a fan. I upgraded from a Def Tech Supercube I and it was a big leap forward. I have the piano black finish and it is a sharp looking beast. So, I can't give you a comparison only a testimony that I have found the SB13 Ultra to be a great sub. I have played with buying a 2nd one...I am always on the hunt for better sound!