Jonathan, great ideas and technical speculation. I love it. I have an idea, but I have no clue about electrical engineering so tell me if this is possible. Could the triple stator design be set up kind of like a balanced circuit where one outside stator is at positive, the other outside stator is at negative (both of these inverting between these poles with the signal) and the center stator being at neutral/ground? Would this work and make it a more efficient panel capable of greater excursion? Just a thought.
Rich, a design like you propose has the challenge that basic ESL electromotive aspects generally require a push/pull on a diaphragm from two equally spaced stators.
In your proposal the front diaphragm would have the pull but no push (since center stator is on the center tap (neutral signal)), the rear diaphragm would have push, but no pull (except from the enclosed air vacuum created by the front diaphragm).
So it *might* work if the enclosed air is isolated enough that when one diaphragm moves in the direction of its stator attraction (i.e. away from the centre stator), it would pull, via air displacement, the other diaphragm.
Unfortunately several issues come to mind: While it would generate balanced movements, and works electrically, it does imply that the enclosed air mass is part of the system, and it's mass and 'springiness' have to be factored into the response of the design. But, it might be OK at low frequencies. Don't really know without some further research and testing.
The other challenge is that you basically have not doubled the force exerted on the diaphragms. Since only two stators are energized, and we now have two diaphragms, seems we’ve reduced the amount of force we can exert per Sq. inch. But again, maybe as a whole system, and at low frequencies, the additional gaps from diaphragm to stator allow enough movement to get the SPL necessary .
How this would be any better than a single diaphragm, large-gap, extended excursion panel might only be explained if the enclosed air mass and associated ‘springiness’ are leveraged to dampen diaphragm resonances and allows for ‘tuning’ of the resonance peaks in the system to fit the range it’s being designed for (mid to low frequencies in this case).
Good one, this is indeed another posibility.
