Five feet from the front wall

Regarding the wall behind dipole planars: One of the hardcore Maggie owners on the Planar Speaker Asylum completely damps the wall behind his very-modified Tympani T-IVa’s (he also braces the panels to the walls), other owners prefer diffusers.

Both absorption and diffusion can work; when choosing between the two, one consideration is the acoustic properties of your entire room. If you have a very lively room, absorption is probably the way to go; if it’s on the dead side, perhaps diffusion. Too much absorption in a dead room can lead to lifeless sound.

My room is definitely on the dead/warm side, so I went with diffusion. I have stacked Vicoustic Multifuser DC3’s behind my planars, and have found them to work great. Diffusers don’t absorb high frequencies, they scatter them randomly, keeping the inherent sound of the room intact. The scattered reflections don’t head straight back to the planar (or listener), so it’s back wave doesn’t compromise the sound coming from it’s front side. But that back wave does enhance spaciousness and depth, not a bad thing imo.

@mijostyn Wrote:

The image is extremally fragile when out of the listening position even by a few inches. 30 degrees or more off axis you can even lose the far speaker completely. 

I like well designed (CD) horns for home stereo playback. Listeners both standing and seated can move up to 60 degrees off axis and still get the same frequency response as center, even in close proximity to the speakers. See below page 8 theory of operation:

Mike

https://www.lansingheritage.org/html/jbl/specs/home-speakers/1985-everest.htm

https://www.xlrtechs.com/dbkeele.com/PDF/Keele%20(1981-05%20AES%20Preprint)%20-%20Monitor%20Loudspeaker%20Systems.pdf

@bdp24  I have apogee duetta 2 speakers and my room is on the live side, but my speakers are just over 82" from the wall and sound great without any damping. I think it depends if you have them far enough from the wall behind the speaker you may not need  absorption .

@ditusa 

Yes, a good horn can have almost the same frequency response way off axis then they will fall off dramatically which is an advantage as it limits room interaction. But, that is not the problem. Horns are point source drivers and like any point source driver the volume level drops off rapidly with distance. The center image shifts like any other point source driver and you can still lose the far speaker far off axis. 

With a line source array I can stand 3 feet away and right in front of one speaker and still hear the other.

@invalid ,

I had Apogee Divas for 6 years. It does not matter how far off the wall you are. If it is a hard wall behind the speakers sound deadening will always improve image specificity. The farther away from the wall you are the more of the wall you have to cover. Closer to the wall, like 3 feet and you only have to do right behind the speaker. This only control frequencies over 250 Hz. At three feet you will attenuate 185 Hz which will take some of the snap away from the sound. If you move it farther away you will attenuate lower frequencies. At 8 feet you are looking a 16 foot wavelength 180 degrees out of phase and that would attenuate  70 Hz. Unless you are using subwoofers (which I highly suggest with those speakers) you are missing a lot of bass. It is a compromise any way you look at it unless you want to move them to the front lawn.

@bdp24  I take it you were not direct driving the Divas, it's a whole different animal if you are using an active crossover and directly driving the speaker. I don't like using subwoofers with the apogees,  I've never heard a subwoofer that has the speed of the apogees.