Distance from the front wall for magnepan mg 20.7

Some Maggie experimenters are enthusiastic about locating the panels very close to (or right against) the side walls, with the tweeters "inside" (away from the wall) of course. The side wall acts as a baffle, preventing dipole cancellation on that side of the speaker. And unlike non-planars, placing Maggies so close to a side wall does not create drastic side-wall reflections to the degree the former do.

Others have added Tympani bass panels to single-panel Maggies. Those panels are the perfect sub for use with smaller Maggies, producing the best low end of any speaker I have ever heard. The Tympani’s require a lot of real estate, which you have.

Another good choice is an OB/Dipole sub, as those offered by GR Research in coordination with Rythmic Audio, as close to Tympani-quality bass as you can get. A VERY different kind of bass than that produced by sealed, ported, or even Infinite baffle designs. Leaner---no fat or "plumpness", no "room boom" (less excitation of the lateral room modes. Like planar loudspeakers, there is dipole cancellation to either side of the OB H- or W-frame). As a bonus, as the listening distance from the sub changes, it does so in exactly the same manner (SPL drop-off) as do planar loudspeakers, which is NOT the case with the other subs. With them, the loudspeaker/sub balance is "correct" at only one listening distance. With an OB/Dipole, the balance between it and the loudspeaker is the same at all distances.