Several thoughts, my system uses Crosby Quad 63's and Entec LF40's. After many years of moving the Quads around my 19' by 29' room, they are currently sitting a little more than 8' from the back wall and about 4' from the side walls, toed in toward the listening position. Demian Martin of Entec has visited my home two times and he feels strongly that any dipile should be a minimum of 8' out from the real wall to insure enough time lag between the direct sound and the first reflection so that the ear does not confuse them, otherwise imaging will suffer. I guess that the same result could be accomplished by attenuating the back wave with damping mayerial; however, in my room that seems to suck the life out of the sound. After much experimentation, I have ended up with two 8" diffusors centered on the wall behind the speakers and a single custom 16" deep diffusor in each corner of the room. I also use 5 of the Argent Room lenses and two custom 16' resonators in the corners behind my listening position.
Even with the subs the Quads do not play at really loud levels, but up to f, they are great at differentiating dynamics. This is particularly true from p to ppp.
I found it particularly difficult to seemlessly mate a sub with the Quads, but am reasonably pleased with the latest Entecs which incorporate less motional feedback than their predecessors (yes, the subs still sometimes outpace the dynamics of the Quads).
Last, the outboard crossover that came with the Entecs was horrible and colored the sound of the Quads. At present I use a teflon cap at the input of my amp and a separate attenuator that is in series only with the subs to set levels.
Even with the subs the Quads do not play at really loud levels, but up to f, they are great at differentiating dynamics. This is particularly true from p to ppp.
I found it particularly difficult to seemlessly mate a sub with the Quads, but am reasonably pleased with the latest Entecs which incorporate less motional feedback than their predecessors (yes, the subs still sometimes outpace the dynamics of the Quads).
Last, the outboard crossover that came with the Entecs was horrible and colored the sound of the Quads. At present I use a teflon cap at the input of my amp and a separate attenuator that is in series only with the subs to set levels.