To be honest, I don't find my Spatial Audio M4 TurboS to sound anywhere near its potential until I have them at least SIX FEET (!) from the wall behind the speaker. In fact, I find eight feet is much better than six. I can't say I notice any lower-midrange congestion when placed like this, although I can feel the baffle vibrating quite noticeably. At eight feet, the imagery is easily the best I've heard from any speaker, and I also own some expensive competitors. At three feet, this imagery vanishes. Also, at eight feet, the resolution is also far and away the best I've heard; you can hear individual violins in a string section, for example, and amazing reproduction of ambience, reverb tails. My only gripe with the M4 is the aggressiveness they can have with bright recordings. The top can just about take your head off (figuratively speaking!) at times. I'd imagine the new generation of SA speakers attempts to remedy this. But forget about them anywhere remotely close to the wall behind.