DUNLAVY SC-VI

A good friend had Duntech Princess (more similar to DAL SC-IV) in a 20x20 room with a 9' vaulted ceiling and they sounded fantastic.

HOWEVER, read any source on acoustic design and they all recommend against a square room (avoid standing wave reinforcement). I think my friend's room worked so well only because one end has a 6' wide opening into a smaller room plus an open door way leading to another room; in other words his room was not square acoustically.

I would suggest contacting Rives Audio or other acoustical designers to discuss your situation. And I will suggest that all Dunlavy designed speakers work best with placement well out from both the front and sidewalls. I would be more concerned with sidewall distance than distance between speakers (meaning 4-4.5' each side with 10-12' between speakers [centerline to centerline] in a 20' room). In my experience the 10-11 feet to the listening chair that Daverz suggested will be the minimal distance. Such tall speakers need distance for the drivers to converge, particularly time/phase coherent designs like the DAL.

Room build means that I am purpose building a room for audio listening. Everything will be acoustically optimized including room treatments. Audio processors make me cringe even though they can be very effective. I think I have the width thing down pat, I am more concerned about low ceilings. 9 foot at the front wall and 6 foot at the back. 7.5 foot ceiling height 10 feet from the front wall. This means if they are 2 feet from the front wall, listening position should have a 7 foot ceiling height roughly. Perhaps I should place the speakers at the short wall facing the other way ?

I think you want the speakers firing away from the short ceiling side so that reflections are not "focused" on the listener by the ceiling, but I don't have any empirical acoustical data to back that up.

Alissatweaks, That's what I thought. With that in mind, is there a reason the room is 20' X 20'? Doubling dimensions is usually not the best way to go. I don't share your disdain for audio processors, and with those dimensions, such a piece of equipment might be helpful. I agree with Daverz that firing the speakers from the short ceiling side might be preferable, with that in mind the Dunlavy SC VI's height might be an issue.

I, similarly to Pryso's friend, had Duntech Princesses in a 20 x 18 room with openings going out from the back side so it presented a larger acoustic space, and I think that was the most a room of that size could handle (I tried the Duntech Sovereigns, equivalent of the Dunlavy SC Vs, and felt they were just a little too large for the room). I think the room size you are talking about might be better suited to the SC IV or possibly the V. Part of it is the distance you need to sit back from the speakers for proper driver integration as Pryso notes, the other is bass loading in the room. And I agree with others above, try to avoid a square room if you can, since it is being built. The VIs are a great speaker system, but I think to hear them at their best you might need a slightly larger room or some room equalization to tame the bottom octaves.