Speaker stand spikes ~2” long?

Any coupling point should be of 1 continious  run of the same material. To be made of more than one material shifts the tone, weight and acoustic transfer speed of the device. Almost as bad is the of use an adjustment nut which decouples the primary large conductive flange from either the speaker or the component. You are also altering the sound by introducing a disruptive shape made up of several right angles the worst sounding angle in existence a threaded Nut..A simple cone shape of just one primary angle allows energy to go down but will also some allow some energy to be reflected from the floor back into that singular geometry introducing interfering energy into the signal path. Tom

Tom, Thanks for this info. 
Have speakers with an aluminum base, down firing sub active in each. In looking for a good spike should I use aluminum? 

For clearance here...I work with Starsound/Audiopoints..but I also have my own company Tone Acoustics. I started years ago to prove a point that this techology will work on most anything that touches the floor..cello and bass and bass clarinet for sure..anyway we use brass the metal of music. I am a fan of what we do. Tom

"A simple cone shape of just one primary angle allows energy to go down but will also some allow some energy to be reflected from the floor back into that singular geometry introducing interfering energy into the signal path. Tom"  

After much experiment I found this to be true. Now using solid cones to leather pads over suspended hardwood. For the sonics of my room, way better than threaded gliders or rubber feet.

The two primary variables for audio cones are material, size and shape. Oops, that’s three variables! The cones should be extremely hard, not like brass or aluminum or carbon fiber which are pretty low on the totem pole 🗿but like tempered steel and NASA grade ceramics. The cones should be ballistic shaped with the very best shape looking like the tip of an ICBM 🚀 Hey, I just described the Super DH (Diamond Hardness) Cone! The Jumbo DH Cone is the same ceramic materiel and the same size but not quite as ballistic in shape as the Super. And it’s performance is not quite as high as the Super but almost.