Easily the best $230 I've spent in quite sometime. The original price was around $600.
Goes way down to 23 Hz, so no distortion. The 300 watts pushes out all the deep bass, even at lower levels.
Yes, you could crack your windows, or drive your neighbors nuts. But if you stop and reset your settings on your A/V system, you won't. Mine is at about at 40% volume and delivers the low end perfectly. Will actually make your whole system sound better as your lower powered satellite speakers will not be trying their best to push out so much of the lower end.
This works great with the Polk RM6750 system. The subwoofer that came with the system is OK, but would sometimes distort when hitting the deep lows on a blu-ray HD soundtrack (Iron Man, Star Trek (2009)). In fact, I still leave that older one on except for my blu-rays to make the final 0.1 in my 7.2 Yamaha RXV765BL system.
It also performs very well with music. Miles Davis' Kind of Blue never sounded so good. You can really pick out Paul Chambers' work very well.
Only one warning -- it is fairly heavy and probably bigger than you think. Make sure you look at the dimensions before you buy. You could (but don't) use it as a spare side table!
I now know why people pay so much for a good subwoofer. This is a great one and not made anymore. Grab one at this absolute steal of a price before it is gone.