LOL, I've been moving the speakers up 1" per day from the back wall in hopes my wife won't notice. You are probably right, it's the back wall reflections.

Yep, hence the typical arrangement of loading up the wall behind dipoles with panels and traps - most people with dipoles just try to knock out the rear wave. If you can, try using diffusion there instead. If you get it right in terms of of the delayed reflection, the space will sound MUCH larger than it actually is, without the imaging issues caused by early reflections from the wall behind (and possibly the side walls depending on what you have there.)

For a diffusor, a bit of rough concrete in a with an U shape is pretty good. Or better yet, chunk of pumice - both absorbs and diffuses.

I'm not the first to do it. I believe that honor goes to Celestion with their System 6000 in the 80s. I built my own dipole woofers in the early 90s to go with their SL700SE and later continued this configuration with the Sequence

Very cool. Couldn't you get to the same goal with monitors and dipole subwoofers though? That would open up more options in terms of being able to use dedicated amplifiers and PEQ etc without affecting the main speakers at all, for those of us that like a "less is more" approach.

[quote author=Donald North link=topic=1436.msg37892#msg37892

I don't clearly understand your question. Can you elaborate please?

Yes, you can use monitors with dipole subwoofers which is what the Celestion speaker was (SL600 monitors with System 6000 dipole subwoofers & active crossover). Dipole woofers provide their benefit below 200Hz where the room modes dominate, so in my experience it's best to highpass the main speakers/monitors. This can be done as simply as a strategic capacitor in series with the amp powering the monitors. For my personal setup I built the highpass filter into the 2A3 PSE amps powering the 95dB efficient midrange-tweeter array.
[/quote]

What I mean is, run the subwoofers from the pre-outs of the linestage to high-powered SS A/B or even Class D if you want amps with whatever type of EQ you like, and then the main outs to Class A monos powering the monitors. The subwoofers could be placed where ever they are most effective in the room, there's no need for them to be attached to the monitors in any way.

Basically, the same idea as a typical monitor/sub setup, just with dipole subwoofers instead of traditional woofer in a box types.

Your Sequence speakers are at the top of my list of things I want to hear most, Donald. Do you take them to shows?

I'm pretty much set on making the jump to speakers. It's mostly just a question of when now....