There's stuff going on that results in some gain.
Okay, this one I can give a decent answer to. This is highly counter-intuitive, but imo utterly fascinating, and I use it in my best-sounding home audio speakers.
Controlled blind tests have been done on the effect of reflections on the intelligibility of speech (a great index for clarity). While very late reflections (echoes) are detrimental, oddly enough, reflections that arrive within a fairly generous early time window actually enhance speech intelligibility! Perhaps the world's leading researcher in the field of psychoacoustics, Floyd Toole, theorizes that the ear can do a better job of deciphering a complex music signal if it gets multiple "looks". And here's another wierd part - the reflections do not have to be coherent! The ear/brain system doesn't hear waveforms; more like packets of energy, that stimulate the frequency-specific cells in the cochlea. In fact, diffuse reverberant energy is perceptually more desirable than strong, coherent reflections.
My best home audio speakers are bipolars, which radiate full spectrum front & back (conceptually not unlike an open-back guitar cab, except that's a dipole so it cancels at low frequencies). So we should have twice as much "blurring effect" from the doubling of in-room reverberant energy. But guess what - the net effect is enhanced clarity and articulation, relative to an equivalent monopole speaker, even though the in-room impulse response of the bipolars would be atrocious in comparison.
So imo it is theoretically feasible that the backwave energy the Big E's harvest actually enhances clarity. Theory aside, such has been my observation.