To summarize my setup in short: I have a whole-house audio system setup. I have a big dedicated 2-channel amp (Rotel 1090) in my wiring closet going to a distribution block. From there 8 pairs of speaker cables go throughout the house to volume control switches (100 watts RMS max per channel per pair). So in the end I have whatever pair of speakers connected directly to the wall where they directly fed power that is moderated by my volume switch. To summarize what I want in short: For parties and such, I'd like to get a little more bass output from the speakers in the 'party' area of my house. They already have 8" drivers built in, and produce moderate and very clean bass, but being in a large open area, they just don't put out bass I can feel. And the problem is: I have no way of getting a dedicated preamp signal to a sub in this area of the house... especially not one that is synchronized with what the amp is playing upstairs in my wiring closet. So my question is: Are there any subwoofers out there that are capable of taking a full-powered audio signal that is destined for a speaker (or pair of speakers), mooch off just enough power to get a satisfactory "preamp" feed, and then pass the power along to the speakers themselves, all without making any noticable difference in the sound quality of the sub and/or the speaker(s)?