Eminent Technology LFT-8c Robert Greene review

OK..with the several recalculations for ledoux1238, I figured there has to be a way to generalize the setup for all room speaker and listening position placements..in essence, as known in my former life, a generalized calibration curve. A benefit to the repeated room calculations (and necessary condition) is they offer the base-data to generate an empirically-derived predictive model.  Not surprisingly, there was a way to do this and it's pretty basic. What was surprising, was that it took ChatGPT about 15-20 seconds to churn it out.  The usual response time is instantaneous or a second or two. While I'm new to the A-i thing, there's some amount of satisfaction in asking a question that takes that long to answer.  The whole curve thing, in hindsight naturally, is quite simple.  Also in hindsight, there's no way I'd have ever taken the time to work this out manually, though it's do-able, as it would have taken (me) waaay to much time. This is a case where humans(supposedly the "smart" ones) ask questions and machines answer them. 

(Forgive my continued flogging of this (setup) dead horse. This is my idea of fun..and something useful to do while listening to music)

First we need to define a Space  Ratio (R) 

R = (on-center speaker spacing) / (listening distance)

R = (spacing) divided by (listening distance)

The chart below can be used to self-check on whether you're using the calibration curve correctly. (locate your unique ratio R on the x axis, go vertically the dotted line, then travel horizontally to the y axis to read your toe-in angle)

Quick mental shortcut (no math) — Behind-head version

You can estimate toe-in instantly:

• Speakers narrower than the listening distance
  → ~18–20°
• About equal spacing and distance
  → ~23–25°
• Speakers wider than listening distance
  → ~25–28°

What the calibration curve really means:

As R increases (wider speakers or closer listening):

• Toe-in increases
• Lobe steering becomes more critical
• Sweet spot gets narrower

As R decreases:

• Toe-in decreases
• System becomes more forgiving
• Imaging stabilizes naturally

I'm having way too much fun with this..

Did anyone see my question above?

It's answered several times in the responses above..the listening triangle that serves as the base of each toe-in calc.

..and @bdp24  thank you for chiming into this thread. It's good to have you back from the hacked-hinterlands. Without ledoux's questions, your detailed responses, and ledoux' followup, the above setup info wouldn't have happened. 

I'm about 4 hrs into a listening session at 24.5 degrees(quite different from the previous 15 degrees). So right. So good. A new track comes on and I continue to say.., oh my..

@nogaps:

I haven’t heard the MG3.7i’s enough to have a credible opinion of their sound quality, but like you I found the models below it to sound "ghostly"---images appearing as apparitions rather than flesh-and-blood bodies and instruments (like a speaker with out-of-phase drivers)---and "wispy"---a thin spectral  balance. They absolutely demand subs.

The Magnepan ribbon tweeter (found in the MG3.7i, 20.7i, and 30.7) is a push-pull design, as is I believe the midrange driver in the MG3.7i (I don’t know about the woofer driver). The 1.7i and lower are 100% single-ended, with magnets on only one side of the Mylar diaphragm. Ugh.

While the tweeter in my Tympani-T-IVa’s is the excellent Maggie ribbon, the midrange and bass panels are both single-ended. Some Tympani owners have replaced the midrange driver with a row of the no longer available NEO 8 planar/magnetic driver, and Danny Richie employed a row of the NEO 10 midrange driver in his line source planar/magnetic loudspeaker (mated with Neo 3 tweeters and Rythmik Audio/GR Research OB/Dipole Woofers. Fantastic! Audiogon member jaytor shows his pair in his Virtual System).