Anyone Damp the insides of your Speaker Cabinets?

If you want to add material to suppress vibration one of the better materials to use is polyester batting.

It comes in different thicknesses and can be found on the web or at a local haberdasher.

It will hold it's shape and thickness compared to other materials.

Google fatt batt :-)

I own a pair of Allison CD8s. I have always liked the way they sounded. I read in an issue of Audio Basics Magazine about applying plasticine to the interior of the speaker housing and to the speaker frames. I figured 'why not' if I didn't like the results, it was easy enough to remove. I am pleased with the results as I notice an improvement in the bass response....the bass had been tightened up a bit. I have since left it in the speakers.

All loudspeakers sound best when they are as close to inert as possible. Vibrations just cause "fuzzy" sound. Before you go stuffing the insides--1st seriously consider reducing/eliminating vibration by bracing the walls.
Adding stuffing material will affect the bass response whereas bracing simply eliminates resonances. I have used "well seasoned" i.e.- old- coffee table legs of oak and mahogany to excellent effect. Use PL Premium glue and a snug fit. You can't go wrong by minimizing vibrations this way. It's well worth it.. You will end up smiling with the enhanced clarity and dynamics.

Ptss, if building a box from scratch (or even retrofitting), whats the best way to brace it? I was thinking it would be most effective to put shelves throughout that fit snug on all corners of the cabinet and then either cutting a bunch of small circles out of the shelves or even perhaps just one big one in the center of the shelf (to allow air to pass through). Also, would this approach impede free air flow and degrade sound quality?

B_limo. Interesting tough question that companies like Wilson, Rockport, Magico, Focal, YG, B&W, Dynaudio and others never stop working on. Of course as businesses they must concern with trade-offs. Your question-the best-need not consider trade-offs. I think this question is worth its own thread. I believe there are many knowledgeable, educated people who we hope would contribute. (Will you start the thread?-or shall I, as it interests me greatly as well.) I still have a pair of 1985 JBL 250Ti's whose sound I transformed-in all ways for the better- with bracing, mass and damping (all done with minimal effect on internal volume.