[Poultrygeist]

I can't detect any resonance transference with my OBs. There's padding between my top and the H-frames and the big Alphas are rock solid in the frames. All joints are held together with Kreg pocket hole screws and Titebond. I glued molding on the edges not so much for cosmetics but for more support of the plywood layers. It doesn't show but I used lots of Bondo on the H-frames.

If I had two drivers in the same baffle resonance would be an issue.

[el`Ol]

I am not sure I understand "The construction is a bit open for my taste", the subs sit underneath this just keeps the two baffles separate to reduce resonance in the upper baffle.

If I had to construct it the top would have side walls, but that's a matter of taste. The Hiquphon is still good enough 45° off axis, so I would use only one.

[Sirkevi]

Poultrygeist do think that If I make the H baffle for the subs that the upper baffle wouldn't have any resonance if I used something Like cork or what material would you recommend for separating the baffle what did you use.
 el`Ol I know what you mean I am constantly adjusting the wing on the sides till I find exactly what I want that is one of the things I like about the U baffle but I like the Idea of force canceling with the H baffle.
 

[Poultrygeist]

The inverted T baffle rests on four large stick-on padded feet. I think I bought them at Home Depot. I don't think I'll ever own a better sounding speaker and I've had some good ones.

Last year I built some Frugal Horn Mk3, which unless corner loaded, lack bass. When I bring them into my listening room I use just the H-frames for bass augmentation. The H-frames Alphas are the epitome of versatility.