A few more questions / thoughts if you would please?

In looking at your Nine Pi horn design, I see that it has a 40 degree dispersion angle. Obviously, I know very little to nothing about horn design. But, from looking at a few designs intended to be used in this frequency range for studio or home use. The majority of them are 60 degree to 90 degree horns.
I can only assume that a 40 degree horn would require alot of distance between it and the listeners to obtain a proper stereo image?

Have you experimented with other midbass horns designed to be used in a home environment where distance is at a premium?

If so, what would be a good angle of dispersion for such a horn at these frequencies, from 100Hz and up?

Also, have you experimented with a posible double mouthed bass horn using the basics from your 12 Pi subwoofers, a single push-pull set of woofers.

The idea of a pair of midhorns mated to a single basshorn positioned in the center between them sounds interesting. Using this main speaker set up with a few more subwoofers placed into the rear of the room for distributed bass response might prove very dynamic?

Have you given much thought to this type of system before?

Thanks

Norris

To use a midbass horn like the 9π for home use, I would probably splay two of them horizontally. This would give an 80°x40° pattern, very close to ideal. Then again, since the horn was designed to work well in freespace, it is probably larger than needed for use in quarterspace or halfspace. That's OK - It's always better with horns to be oversized than undersized, at least where mouth area is concerned. But most people don't want monsterous cabinets for home hifi. It might be worth the effort to scale it down a little bit, modeling with Hornresp in π or π/2 space to see how much size reduction is possible and still obtain the desired response.

Regarding push-pull drive, I really like that approach for basshorns but not so much for midrange. I studied distortion reduction mechanisms for quite some time when developing the 12π hornsub, and came to the conclusion that push-pull drive works best at bass frequencies, and shorting rings work best from midrange frequencies up.

Shorting rings work well at frequencies from about 100Hz and higher. They're like transformer windings, and have a lower frequency limit. Push-pull drive is just the opposite, it has an upper frequency limit. The two drivers must be tightly coupled acoustically, so the drivers should be physically close, even better when combined in a common chamber. The coupling is wavelength related, with distance being proportional to wavelength so what's close for a basshorn (where wavelengths are measured in tens of feet) is not so close for a midrange horn (where wavelenths are much shorter). My conclusion is that basshorns are ideally suited for push-pull drive whereas midhorns are better using drivers with shorting rings for flux modulation control.