DUNLAVY SC-VI

In the manual for the SC-III, Dunlavy recommends sitting about a foot from the back wall and treating the back wall with 4" thick acoustic foam (four 4'x2'x4" panels would probably do it). Or at least that's the recommendation for a room about 20x13 in size, where a 10' listening distance would put you near the back wall. (I still have my SC-IIIs and wish I had a room this size to stick them in.) It would be interesting to see what the manual for the SC-VI recommends.

@ Daverz, you are correct in linking that recommendation with the room size.
Dunlavy made seating recommendations based on a list of priorities.
The first was to always use the long wall if possible. This was to first increase the space between speakers but, just as importantly, to increase the relative distance of the direct sound versus the first reflected sound from the side walls.

The second priority was to keep the speakers off the wall behind them as much as possible. This also was to keep the difference in timing between direct sound and reflected sound relatively high. It also helps to increase sound depth.

Of course, all Dunlavy speakers were designed for a 10 ft. listening distance. So the distance from the listener to the wall behind him/her was the last priority. And in normal size listening rooms usually meant the listener was right on the wall. In this case, the easy fix is to cover the area with thick absorptive material. Leaving this wall for the primary wall treatment also meant that you could get away with a lot less material since the closer you sit to the wall the smaller the area of treatment necessary.

Given these priorities it is easy to see how the size of the room will ultimately impact the placement recommendations. Hope that helps!

A lot to consider. The room is being made out of an existing structure which is empty and stripped to open wall studs and open ceiling joists. The slab it sits on is within inches of 20 x 20. If I keep it 20 x 20 then I do not have to do any new roofing, supporting walls, etc.
Putting the speakers on the short wall makes sense to me acoustically since it makes the room more "amphitheater" like.
Kind of like a horn. The only deal, is that I wanted to also add a Runco and 120" screen for a... dare I say it... um... home theater... the 9 foot high wall would be ideal for a sreeen.... perhaps I could do an automatic drop down screen a little off the short wall, so I do not have to try to mount it on a 6 foot wall...

Not a bad idea putting the screen as a drop down.
If I were you I'd invest in a good acoustically transparent screen (so as not to cause adverse reflections from speakers) and hang it so that it's approximately even with the baffle of the speakers. If you use the short wall side this will put it out about 6ft. which will also raise it by ~1ft. which should be plenty high.

It all sounds interesting. Keep us posted!

Have you considered reducing the size of your room? You could have better dimensions, a separate area for your gear that would be exposed to less vibrations, and permit easy access. If your really got creative you could avoid any parallel walls. That would probably sound really great!