I recently upgraded an old Klipsch KSW12 to a Rythmik lv12f and the difference is night and day. Just a word of advice though, when going from a lesser sub to a higher quality sub, it is not uncommon for your first impressions to be "where is the low end?"
The klipsch that I had played loud and boomy... very aggressive and fatiguing to listen to honestly, only I didn't know any better until I made the switch to Rythmik. My initial impression was that I completely wasted my money on a sub with no output. But with a little tweaking and giving it some listening time to acclimate, I began to realize what I had been missing. The rythmik is waaaayyyyyyyy more accurate, tight, and there when it's supposed to be. It is not boomy through the entire film and/or taking away from anything. Only perfectly and accurately complimenting what I am watching. It's one of those things... you don't know how bad what you have is until you hear something better. My only regret with the rythmik is that I didn't buy two when I bought. My model is now on backorder until May. As soon as they are in stock, I'll be adding a second one, just to even out the bass response in my room. Otherwise, I would say that any of the internet direct sub companies will probably be a leaps and bounds upgrade for your space and your ears.
