Stupid idea, questions before I cut holes in my house.


Will Watercool for Crack
Jun 10, 2005
Shit, I typed up a huge thread here, lost it, and now I"m going to paraphrase.

I only listen to music in stereo btw!

I have a really nice set of DIY 3.5' towers next to my bed. Insignia BS21jd102 whatever coax drivers in a sealed box, removed reflex port, and added in a set of 10" woofers, crossed from the amplifier level. Driving the coax's at around 45w, and the 10's at 65w.

I recently messed around with adding an AB/D 3 channel amp to add transducers to the box-spring. This is a lot of fun but I'm only using the D channel - this helps me not piss my neighbors off when listening to music late at night after work.

I found a really nice set of personally refurbed 3 way's from a nice PSB alpha "floorshelf" setup.

I have 2 channels of A/B left to drive, and I don't like leaving these channels empty, as I believe it's bad for the amp topology... I have NO other place to put speakers currently, as I have 4 sets in 3 rooms :/

So, were to mount these new 3 ways in the empty ceiling bulkhead, with appropriate boxes. I lay on my back to listen to music. I'm thinking a box in the ceiling, a few inches beyond the cones of the towers, with the appropriate delay set to a few ms.

I get a *very* 3D soundstage currently - so I'd like to avoid adding speakers aimed at me, as they'd be firing towards the soundwave of the towers, and I know I"ll get too many room modes - unless I wire them 180' out of phase I suppose. I'm hoping the 90' rotation from ceiling boxes might extend my perception of 3D sound - from back listening - , without introducing too much interference. The install would be very easy with the current bulkhead.

So like, as I barely know what I'm doing after even 10 years building speakers and amps... Is this a stupid idea before I open up drywall?


Supreme [H]ardness
Nov 1, 2012
The amp doesn't care if you have channels undriven and most likely the extra output you see is just parallel wired to the same amp. If you install multiple speakers that play the same source signal to your room they will interfere with eachothers and create a comb filter effect (sound comes and goes when you make small movements with your head). Not advisable...