I plan on stuffing the hollow with "something". Be it plasticlay, sand or what ever, that was the initial plan. I'm not going to go into the speaker building theories, but for me, the stable mass and dead sound of the material was, for me, the way to go. I've learned from making ARMod, that all vibrations need to be squelched. I'm not sure if MDF is that material.
I'm doing this project cold turkey, so if I fail, it's out in public, but I think I'm on the right path. ONLY playing the table will reveal the true nature of my engineering. There are going to be tweaks. If any of you know about ARMod II, it was burnt up in a midnight recreational fire. Can one have success without failure? If your in any kind of engineering, you have worn lots of egg on the face. It's humiliating. It's really fun to see young people entering the field and making the same mistakes I did, when I was 22. That is part of growing up. It's two worlds apart. There is the design, and then the reality. I believe that Edison tried over 10,000 different materials before he found that tungsten in a vacuum would glow. The guy never gave up. Hense the old saying that genius is 1% inspiration, 99% perspiration. I'm of the later skool.
I have 3 US government patents, made $3 dollars off of those, and believe me, the effort was not rewarded, having the patents is.
I fear the motor module that is next. Lots of machining.
Wayner.