By this way you have total control over weight density
https://www.compositesworld.com/articles/microspheres-fillers-filled-with-possibilities
Filling speaker Stands?
My suggestion is 2 pot expandable PU foam with Pebbles or/both light weight filler diatomaceous earth, micro spears rock wool mix ... https://www.homedepot.com/p/12-oz-Fill-and-Seal-Expanding-Foam-Sealant-2-Pack-217272/203459971 and https://boatcraft.com.au/Shop/index.php?main_page=index&cPath=37 By this way you have total control over weight density https://www.compositesworld.com/articles/microspheres-fillers-filled-with-possibilities |
You need to dampen vibrations and that means more than just adding mass. Sorbothane is the only material I know of which actually converts the mechanical energy to heat, thereby getting it out of the system quickly. I recommend 1/4 inch self stick sorb , of the densest form, 70 duro. Use small pieces of sorb eg. No more than 1 inch across and cover with 4 layers of electrical tape, so as to make this a constrained damping set-up. You can stick these all over your speaker, I place them on the front, and thus hide them with the grill. The effects are amazing. The big companies are only slowly moving this way. Search constrained damping and you will find a lot of speakers doing variations of this. Grado and Sennheiser are using similar damping on their phones, although with Senn it appears to be only with their top.models. |
My advice: Use fine sand and tamp it down well. Why? Deadens vibration and adds mass. Lead has no advantages (and some setbacks). And... it can be toxic. I also suggest decoupling the speakers from the stands. Sorbothane works, but you can even use four big globs of Blu-Tack (or museum putty, which is the same thing at 1/3 the price) near the corners. |
This is perfect advice, though tamping down the sand is a bit extreme, especially if is dry. |