Hi, i have just ordered a 500 watt version of the Monolith DF sub for my theatre organ set up... here is a link to the site for those who are interested...
http://www.bkelec.com/hifi/Sub_Woofers/monolith-df.htm I will post up the results when it arrives in about 2 weeks. The guy i ordered it from says it will drop to 15HZ in the middle of a field ! It has really good reviews from many sites on the web, and says it is not for the feint hearted.
I have the 200 watt 10" downward firing subwoofer from the same company which is awesome, but just doesn't give quite enough volume output compared to the other 10 speakers.
Chris