Sand or Lead shot

Using sand should suffice for audio stands. For speaker stands l would use both materials, albeit shots of various materials can and will become very costly. I don't think there will be significant improvements using shots for an audio stand. Use the money for isolation platforms or component footers. Good luck with the stand!

I agree with, and second what Jcbtubes said. I use the Micro-Bearings with great results and highly recommend them. A bit pricey but worth it. “One bearing, thinner than a human hair and smaller than a grain of sand (.0087 millimeters each), multiplied by many billions provide additional conductive mass. This increased density improves the audible(and inaudible) sound quality and performance of any equipment rack and/or loudspeaker stand by reducing detrimental vibrations.
One quart of Micro-Bearing Conductive Steel weighs in at approximately 9 pounds. Being round in shape, coupled with the extremely small size, permits the mass to become uniform in grain structure with no air pockets positioned between the bearings”.
I’m in no way associated with this product, I simply find that it works very well.

Unless you have cement sub floors, I would not bother with lead shot (even in a mix). Silica sand is a very good all-rounder and it is inexpensive. Even though it's sand you should still wear a mask or kerchief when working with it in the open.

Be certain to purchase sterile/dry "Silica" sand.

I haven't seen lead shot available in stores. Only steel shot. This is what I have used for quite some time. I think it works very well. It's not as messy as sand. Don't have to worry about it collecting moisture like sand can.

A few comments: Sand doesn't collect moisture if it starts out dry and is in a sealed enclosure. Lead is not a health hazard unless ingested. IMO, though, sand is just fine for most damping applications. The only benefit of lead or steel is increased mass, which can be helpful but isn't always.