Apologies to Norah Jones, I needed more bass!

@billpete  - It may help you to see the wiring.  Take a look on my blog, the second picture shows how the amp is mounted on the back of the woofer section and how it connects to the mid and treble on the bookshelves. 

This saves me a great deal of device and wiring complexity.  I have 1 wire from the HT processor to the back of the plate amp, then short speaker cables to the top section.  This is a lot simpler than a "discrete" setup using a stereo crossover, plus 3 stereo amplifiers.  Talk about messy wiring! 

@billpete - Going back to your comments about power, using active crossovers changes the power to voltage relationship.  Power is proportional to the square of the voltage, so a single amp that has to do midrange and treble and bass must be rated much larger than it would if it did them separately.  

In other words, if I attempted to do this with a single mono amplifier it would have to be rated at well over 1,200 watts, much more than if we add the 3 amplifier sections together to 600W.  At my listening levels and music and movie tastes this is all serious overkill.  I doubt I hit 20W.  

@erik_squires Interesting set up. Much of this is over my head but it is interesting just the same. Thanks for sharing. 

@erik_squires Is this a multi channel HT type of system? Is this how you listen to your music? I do my serious listening in Stereo mode only and do not own any HT type of gear. For movies and TV, I'm happy with soundbars and small subs. I have a lot more wrapped up in stereo equipment than anything like HT. Just wondering if you listen to stereo recordings this way and how that affects things. I have a few DVDA recordings that have 4.1 and 5.1 options but also have stereo options, which is how I listen to them. Not trying to be a pest, tell me to piss off if you get tired of this. :)

@billpete 

 Is this a multi channel HT type of system? Is this how you listen to your music?

It is.  I had a separate HT receiver, and Luxman integrated and used the Luxman’s bypass feature to listen to movies however after doing an active center channel project I decided I would rather have something simpler, with powered speakers, than keep the hybrid system.   In particular, hearing how good the center channel came out convinced me I should make the plunge. 

I use the HT receiver but in stereo mode for music, except when I play music related DVDs.  I’m currently working through Berlioz’ Les Troyens.  The music is fabulous but oh, I wish I’d never seen the subtitles...