At one time, one of the fads (?) in Hi-Fi circles was to get squash balls (not squashed LOL), cut them in half and place them under Hi-Fi equipment - especially under CD players. Not sure if they recommended them under speakers (unless you have a hard/laminate floor). The recommended trick for speakers was to either:-
use spikes provided directly (they would go through a carpet)
or
put some philips screws in the floor and put the spikes into these.
If your speakers didn't have spikes, then you had to improvise.
After that, you get into the "Belt" philosophy about improving the sound, but nowadays most people probably don't bother (or don't know what the h*ll I'm going on about!).
When a lot of people are listening to mp3 they don't care about Hi-Fi.
Now if someone would like to elaborate/contribute .........