If anyone was really curious about vibration control it'd be easy to add rigidity to a box. Go to Home Depot, but a pack of ceramic or porcelain floor tiles, and attach them to the flat spots on the speakers. Some double sided carpet tape might be enough to test with as long as the tile is completely flat. Those tiles are extremely stiff and would definitely take any flex out of the box when attached adequately. You could also embed metal in the MDF the way Merlin did to reduce box flex.
I've been working on a concrete baffle kit for a while, I posted about it a couple of weeks ago. I've got it to the point where there's something to show but it's not done yet, too many other higher priorities.
https://imgur.com/fzHUooF
I've been working on a concrete baffle kit for a while, I posted about it a couple of weeks ago. I've got it to the point where there's something to show but it's not done yet, too many other higher priorities.
https://imgur.com/fzHUooF