I'll post some photos soon, but first a story:
I drove Jim, Mike, and Sam nuts with my rattle problem. I had my HT3's back to the shop twice because I could not get them to stop rattling. Especially on 2 or 3 tracks I kept playing that excited them in such a way that no matter what I tightened on the inside or Jim relgued or bolstered could solve it. I really felt like I would need new cabinets or external xovers, or something drastic to solve this.
So finally I realized that whenever I touched the cabinet to try and feel where it was coming from or dampen something it did get a little better. Duh! I was planting it tighter to the floor and that was the problem.
You would think the weight of the speakers and the spikes would be enough, but with my laminate floor it was not working. There is a tremendous amount of bass generated by those TC Sounds woofers. Taming that would take a drastic step. So I removed the spikes and placed the plinths on 2 slabs of 1/4" Sorbothane and shazam!, problem eliminated.

Only thing now is the speakers are sitting lower than I like them and I want them taller. So I batted around a few ideas and sketched this up at the dentist's office Friday afternoon. I cut and laminated 1/2" MDF strips into 1.5" slabs, glued and screwed them up and left them to dry.

And then Saturday I had to go school clothes shopping - yuck, so they sat until after dinner.
I mitered the pieces so that I could make a 4 sided box (fake plinth) that was 1/4" larger than the actual plinth on the speaker.