@fluffers , you have an absolutely magnificent set of speakers. Very nice choice.
Here are some general principles that might be worth being aware of:
1. Early reflections are detrimental to imaging and clarity, and can cause coloration. The relatively narrow pattern of your T1.4's (in both the horizontal and vertical planes) works in your favor here.
2. Late reflections are generally beneficial as long as their spectral balance is similar to the first-arrival sound. Again, the relatively uniform directivity of your T1.4's (resulting on smooth off-axis sound) works in your favor.
3. As a general guideline, the "fuzzy dividing line" between "early" and "late" reflections is about 10 milliseconds, during which time a sound wave will travel about 11 feet.
4. Decorrelation is your friend when it comes to the reverberant field. If we can get the left speaker's reflections to arrive at the right ear before they arrive at the left ear, that would be great. When the first reflections arrive at the opposite ear, the ear/brain system tends to interpret them as spaciousness. When they arrive at the same ear (especially if they are "early"), the ear/brain system tends to interpret them as coloration.
There is an unorthodox setup geometry that takes advantage of the beneficial radiation pattern of your T1.4's: Extreme toe-in, such that the speaker axes criss-cross a foot or two in front of the center sweet spot. I use 45 degrees as a starting point. This results in negligible early reflection off the near-side wall; instead, each speaker's first significant sidewall reflection will be off the OPPOSITE side wall. This not only gives a long time-delay, but also gives us decorrelation, as now the left speaker's first sidewall reflection arrives at the right ear, and vice-versa.
An additional benefit of this aggressive toe-in is an unusually wide sweet spot, with decent soundstaging across a much wider area than you get from a more conventional setup. You see, the ear localizes sound by two mechanisms: Arrival time, and intensity. For the off-centerline listener, the near speaker "wins" arrival time, but the FAR speaker "wins" intensity, because the listener is far off-axis of the near speaker but is very much on-axis of the far speaker, so the two localization mechanisms average out to a certain extent. The KEY to this is, the response of the near speaker must fall off smoothly and quickly as we move off-axis, and a good horn or waveguide speaker does this (conventional cone-n-dome speakers do not).
So at some point as you are experimenting, you might give this extreme toe-in suggestion a fair chance to win you over. You might need to adjust how far apart the speakers are, and you want to avoid having reflective objects in between the speakers.
Regarding soundstage depth and distance out from the wall, your T1.4's will be far more forgiving than most speakers because their radiation pattern doesn't allow much early energy to reach the wall behind them, at least not in the mids and highs (which are what matter the most for imaging). So you can focus more on what distance from the wall gives the best bass. Also, as you move the speakers forward you will be increasing the ratio of direct to reverberant energy, and you may find that the imaging becomes more precise but the sense of envelopment is decreased. So there may be tradeoffs, but my guess is there will also be a "Goldilocks zone".
Duke
dealer/manufacturer/fan of Classic Audio speakers