Odeon, I would really like your input on my new design.
I have been doing this for quite a while, now, but I respect your knowledge of things physical.
Can you imagine two large (dual eighteens) drivers each facing a kind of static pressure field, tempered by teardrop shaped (like used for high frequency drivers to align the outside of the diaphragm with the inner curve of the moving mass) cone supporting complimentary shapes, quite the opposite of what HF diaphragms need.
Low frequency drivers just need to remain in piston motion; no sideways motion, ever, just pure piston motion.
Low frequency moving masses need to be supported on both sides, right and on all moving surfaces, right?
So I have a really tight back support and a kind of pressure related support on the driving side, just like the compensation afforded HF drivers to keep phase aligned. But here, we are not worried about phase (wave lengths are more than ten times the cone widths) we are trying to keep the cones performing as true pistons. My old JBL guy told me to give it up.
I have just re-invented the wheel.
WTF!!
A difference in phase would still give you overtones, wouldn't it? But other than that, I seem to recall that Bose did something similar with a sub design for cinemas. Or rather, they tried to. AFAIK, they're not in that business anymore.
Are you attempting crowd control like they did in the 60s?
The entire plan I have not yet shown.
I know that Bose, JBL, Cerwin Vega, Danly, and Showo have all tried to control a high volume low-frequency driver using pressure on each side of the cone.
What I have come up with is a "way" where the first order anomalies are mostly eliminated before they begin to propagate.
Yeah, I am making a "GIANT" subwoofer, possibly capable of "crowd control," as you suggested. I am more interested in its value as an extreme output device in the lower two octaves of human hearing.
Something a band owner would want. Something musical.
I will show you my three chambered device when I have a working model.