All Merlin family members.

While I agree that its better to have nothing between or behind the speakers, I've had less negative impact in a larger room, with speakers positioned relatively further into the room. IOW, if there's still plenty of air between and behind the speakers, it isn't quite as problematic as the same setup in a smaller room.
One point worth addressing when you place gear on a side wall; don't place a turntable at the primary reflection point, or you risk creating a feedback problem. Ideally, you would want room treatments at that spot anyway. Cheers,
Spencer

I recently relocated several equipment racks that had been in between and 1' behind my VSM-MXs, to remote locations away from the speakers. Now the opening between the speakers is 8' wide and about 3' deep to the front wall, with only the amp on the floor. Imaging improved, the soundstage expanded vertically and horizontally, but surprising I'm not getting much greater depth than before.

In my room the Merlins are better than the Wilson W3/P2s they replaced by any measure except for depth of soundstage. The Wilsons produced great depth when placed in nearfield positions well out into the room. Merlin VSMs don't work well in the nearfield.

Next step is to treat the cleared front wall.

Dave

that will help dave as i am sure you have a lot of reflected energy conflicting with the direct radiated information. this will obscure the contrast potential.
none of my designs are nearfield monitors. they are too uniform for that and are designed with their power response rather than nearfield on axis.
hope it works.
bobby

Are there some front wall treatments that work better than others? ie....cloth wrapped insulation, heavy carpet, drapes etc. Does one really have to go to this extent?

I suppose ideally, if your wall is 13 ft. wide, you should cover the whole thing, right?

Capt,
You raise a big topic of its own in a few concise questions.
Indeed some treatments work better than others. It depends on what your room needs(e.g. relief from echo, bass absorption, etc.) In most cases, covering a whole wall is not a good idea.
I'd suggest reading up on basics of room acoustics on either the rives.com or realtraps.com websites. With a cheap radio shack sound meter and a Stereophile test CD you can get a useful(though not perfect) read that will help point you in the right direction; that is you'll have a better idea what ails your room. Then you can post more specific questions or read up here on how others have attacked their room issues.
FWIW, I've spent much effort recently treating a very challenging room, and the results exceeded most component upgrades. It's usually worth the trouble. Cheers,
Spencer