Filling speaker Stands?


I have a modest system. Continually look for ways to improve it's performance even to a slight degree. I have read many posts about improvements than can be achieved by filling the hollow spaces of some speaker stands with some type of material....sand, kitty litter, lead shot, and some others. Here are the stands I have......
https://www.sanus.com/en_US/products/speaker-stands/sf26/ 
These stands are of metal construction. There are 2 upright support tubes which are approx. 2" diameter. The stands sit on a carpet floor with spikes. On the top plates are a layer of Sorbothane and PSB Imagine B speakers sit on top of that. The 2 metal supports are attached to the base and top plate with just threaded holes about 1/4 " diameter. Pouring some type of dampening  material would definitely require a funnel.
The reason I ask this question is that, when I thump on each upright post, it rings for several seconds. A dampening fill would minimize this but would filling those posts really benefit the speaker performance to even a small degree given my modest setup? I don't know. Probably, few have experimented with this type of scenario.Thanks for any advice.



jrpnde
I use sand in my Solid-Tech columns, and it does the job quite nicely, although it is for my component rack, not speaker bases.
jrpnde OP
Well....I am the OP of this thread. There have been many suggestions as to how to fill stands with small openings, what that fill should be, and to what level of fullness should be. I have learned a lot based on the experiences of many.My take on all of the responses......the only way to find the best solution for me is to try different approaches. Of course, filling speaker stands isn’t as simple as trying other options such as just switching interconnect cables and the like.

>>>>>Eggs ackley! Which is why you cannot AB the various possible solutions, at least not very easily. It’s not that easy to AB one, if you ask me. How can you be sure? People generally pick the one that seems like a good idea and don’t look back. Furthermore, dry sand acts as much as a damper as adding mass. It’s the same idea as the sand-filled iso stands of yore from Bright Star. In addition, like my, ah hem, new iso stand, glass microbeads are much more efficient in their isolating action than sand ever thought of being. It’s along the lines of why woodpeckers are able to withstand tremendous negative g forces without sustaining massive head wounds.

Plus, as I already opined, isolating the speakers would be the preferred solution anyway.
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.
I use uncooked rice.  Your situation of a small opening will require that you find rice with a small grain size.   Advantages:  availability; low cost; moderate weight; non-toxic; non-magnetic; minimal settling and compression.   Rice provides some mass, along with excellent vibration dampening.