Is it possible to have Good Imaging close to wall

"Early reflections off a wall is what compromises imaging usually."

Agreed.

The ear/brain system uses the time delay between the first arrival sound and the onset of reflections in judging the distance of a sound source ("image depth"). This isn't the only thing used, but it plays a large role in most home audio setups.

The ear/brain system can detect the time delay for the reflections that bounce off the wall behind the speakers, and tends to use those fairly subtle cues to interpret a maximum image depth of about twice that distance. Aggressive radiation pattern control and/or room treatment can help here, but ime it's easier to trick the ear/brain system into giving us a deeper soundstage if we can generate significant later-arriving reflections that dominate the ear/brain's depth cue intake.

Recently I've worked with systems that generate fairly strong reflections which arrive later than you'd normally expect, and the result has been an increase in apparent image depth to considerably greater than twice the distance to the wall. Credit to inventor James Romeyn for this technique (a highly directional secondary array that fires from the floor up at the ceiling, and yes it's patent pending), which I use with his permission.

Jim is showing a pair of speakers with this configuration at T.H.E. Show Newport Beach right now. I plan to spend more time listening with them up against the wall after the show, but my own limited testing before they left indicated enjoyable image depth even when positioned within a couple of inches of the wall.

I did not expect the increase in image depth that we observed when we first tried Jim's configuration with purpose-built speakers. I expected improved timbre, and maybe improved sense of envelopment, but the image depth was a surprise. The "feel" is sort of reminiscent of a good dipole or bipole (Jim's system could be thought of a type of bipole), but without the distance-from-the-wall requirements.

Please take my comments here with a grain of salt, as this is a designer saying nice things about his product.

Duke

If there is sufficient time delay between the first-arrival sound and the onset of significant reverberant energy, we can have the best of both worlds - imaging and envelopment.

Reflections done right are beneficial from the standpoint of envelopment and spaciousness and a sense of immersion, timbre, clarity, and liveliness. They can preserve the three-dimensionality of the recording, something that reflections done wrong will degrade. The benefits of reflections done right are why acousticians do not design anechoic chambers for recording studio mastering rooms, nor for recital and concert halls.

Relying upon the direct sound from the speakers to deliver all reverberant information (and suppressing anything that involves the room) looks good at first glance. But what's not obvious is the fact that the worst possible direction for the dominant reverberant energy to come from is direct from the speakers. Controlled listening tests have shown that when reflections come from the direction of the speaker only, the ear/brain system tends to interpret them as coloration. As the direction of the reflections' arrival detaches from the speakers, the ear/brain system interprets it as ambience and spaciousness. As we add time delay to the onset of those reflections, the ambience and spaciousness improve, and any degradation of sound source localization decreases (there are exceptions to this, but it's true for most decent home listening rooms). As we increase the relative amount of energy in a spectrally-correct, late arriving, decorrelated, and diffuse reverberant field, the benefits mentioned increase, up to a point. It is possible to overdo it... imo Amar Bose overdid it.

So I'm not saying there's no tradeoff in sound source localization precision vs spaciousness from reflections done right, but the loss in localization is small, and in return we get significant benefit in several areas.

I would like to comment on one statement above:

"Note that there are also reports (also from reviewers) mentioning that the walls of a (small) room have simply disappeared and what was left was a beautiful large stage. This happens when the amount of secondary reflection is minimal and this is exactly the point that I am making."

That can also happen in a small, untreated room with a loudspeaker system that gets the reverberant field right.

From a show report by a reviewer, of a system that arguably incorporated "reflections done right", in a 13' by 19' hotel room, with ZERO acoustic treatment:

"Really nice, big spacious open sound. Again, it actually expands beyond the physical confines of the room. I don’t think ANY other system at the show has been able to pull that off."

That was written at RMAF 2013, Sunday afternoon, after the reviewers (there were two of them) had nearly finished making the rounds. If anyone is interested I can provide a link to the full commentary by the reviewers, wherein you can tell they are experiencing many of the other benefits I mentioned.

For the record, I never set out to build a speaker with particularly good imaging. My focus is always timbre. Just so happens that, far as the reverberant field goes, what's good for timbre can also be good for imaging.

Imo, ime, ymmv, etc.

Duke