Small dedicated listening rooms

In my opinion there are two main acoustic challenges presented by small rooms, and these are really the same issue just different parts of the spectrum.

Most obvious is the increased boundary reinforcement in the bass region. This can be addressed by tailoring the output in the bass region to take this boundary reinforcement into account.

The other main issue is the over-abundance of early reflections. I subscribe to the school of thought that says early reflections tend to degrade clarity. One solution is to use fairly directional speakers and deliberately position and aim them to maximize the time delay between the first-arrival sound and the onset of reflections.

For instance, your Hornscalas have good directional control. If you set them up along the 10-foot wall, not too far apart, and toe them in at 45 degrees (such that their axes criss-cross a foot or two in front of you), the first sidewall reflection of the left-hand speaker would be the long bounce off the right-hand sidewall, and vice versa. You’d be sitting pretty close to the back wall so you’d want aggressive absorption on that wall behind your head. You might want to give your Hornscalas a try with this configuration before investing in anything else, to test out this theory if nothing else.

Other issues that a small room tends to have include lumpy bass in the modal region and constrained soundstage size. I think those issues can be mitigated as well through some rather unorthodox techniques. A distributed multi-sub system is very effective at smoothing the bass in the modal region (and smooth bass = "fast" bass), and deliberately adding a little bit of late-onset reverberant energy can reduce the "small room signature" that is superimposed on top of the acoustics on the recording. Let me explain:

The ear/brain system judges the room size by the time lapse between the first-arrival sound and the "center of gravity" of the reflections. By adding some relatively late-onset reflections, we can push that "center of gravity" a bit and make the room sound bigger than it really is.

Feel free to ask questions about any of this, as most of it is rather counter-intuitive.

Best of luck with your quest.

Duke

"My thought is that you need to listen in the near field. You mitigate many of the challenges and sacrifice very little.  It is easy to set up, imaging can be stunning and the level of impact and immediacy is thrilling."

Excellent suggestion!

The setup I have in mind is a borderline nearfield setup, as distance from ears to speakers would probably be between four and five feet.   And it might sound better if you scoot speakers and listening seat a little bit closer to one another. 

But I'd still recommend the extreme toe-in configuration, to push those first sidewall reflections as far back in time as possible.

And there are other benefits to this unorthodox geometry:  When a reflection comes from the same side as the first-arrival sound, it has a tendency to be perceived as coloration.  But when the reflection comes from the other side, so that it arrives at the opposite ear first, then it is perceived as ambience and tends to enhance the timbre (assuming it is spectrally correct). 

And one final potential benefit:  A wider sweet spot.  The ear-brain system localizes sound by two mechanisms:  Arrival time, and intensity.  By criss-crossing the speaker axes, we get something unusual for a listener off to one side of the centerline:  The near speaker (obviously) "wins" arrival time, but the far speaker "wins" intensity!  This is because the off-center listener is well off-axis of the near speaker, but on-axis (or very nearly so) of the far speaker.  So we still get a decent soundstage even when listening from off to the side.  The secret is, the near speaker's output must fall off rapidly and smoothly as we move off-axis.  A 90-degree-wide pattern (-6 dB at the edges) works well for this.   And the uniformity of the radiation pattern means that the tonal balance is good throughout the listening area. 

Duke