Never had a need till now, so I don't even know where to buy it. Ideas?

Gun shop?

If you decide to go with shot, I'd make sure it's not lead as you've got a little one in the house.

Axiom sells it here Not what I would call cheap, but does look very nice.

Yup, no lead for me.

Funny, I remember that box of balls. Reminds me of golf balls. In theory, I could use my old golf balls, but I lose about a box of balls for every 18 holes so that wouldn't really work for me...

You would be able to find steel shot at most hunting supply stores.

Since you're dropping it down the main tube of the speaker stands I think lead shot is probably fine. Lead shot is cheaper and heavier, plus it comes in nice cloth bags which are a pain in the *** to open even for a young child.

I couldn't find any Cabela's or Bass Pro Shops near you, but any decent gun store will sell lead shot for reloading shotgun shells.

As a cheap alternative, could you seal the stand enough that you could just fill it with sand? Of course I live near the shore so for me, sand is like duct tape.

I've got a 2 yr old and 5 yr old. Sand in the house? Oh no, I don't want to clean that accident...

Sounds like steel shot, then.

Yeah, I figure w/ shot I can clean it w/ a magnet.

You can do the same with iron filings. Plus, it looks cool on a magnet and you can teach your kids about magnetic field lines. But that would encourage them to let it out of the stand.

Is this (filling the stand) a relatively common practice? Are we talking an extreme amount of vibration otherwise?

The main benefit is that it is less likely to tip over. It probably helps a bit with vibration but I think stability is the main reason.

Another alternative would be to use scuba soft weight bags. The shot comes in nylon bags and usually runs about $2.50/lb. They range from 1 to 5 lb. bags. Scubatoys has some of the best selection/prices. If you are interested in just plain bags of shot up to 25 lbs...... look here.

I still say, run your cables through, seal any cracks or inputs to the stands with epoxy, silicone, marine goop, whatever, then fill them with sand or...fill appropriate bags with sand and drop them in there. Dirt is free!! Unless I suppose you live in a 'concrete jungle' so to speak. Even in a city, there should be lots of heavy, waste material laying around. Like shell casings!!

Maybe I should start a home business selling sand.
INTRODUCING............ 100% SELF ADJUSTING, ACOUSTICALLY NEUTRAL, VERTICLE INCLINATION AND STABILITY ENHANCEMENT MATERIAL FOR SPEAKER STANDS!!!! THIS NEW SPACE AGE MATERIAL IS 100% NATURAL AND RECYCLABLE!

OK, I'm digressing even worse now but I actually have a beautifully hand crafted chess set where the board and pieces are made entirely of light and black beach sand. All the pieces are beach and fishing themed. It's my other prize possession.

But, I still think there must be something around that could be recycled for weights without buying special made shot. Of course, I never looked into pricing so maybe it is a reasonable solution.

The nice thing about lead shot is that it is very dense and very cheap (although not as cheap as dirt ). I don't know the numbers, but a bag of shot probably weighs four times as much as an equivalent bag of sand.