An important question has not been answered yet :
| | mpompey
What kind of flooring does your speakers sit on? Hardwood, carpet, tile?
The aim is to get rid of resonances.
And the best solution depends on the construction of the floor
The optimum would be a solid floor like stone or a glued floor (wood or carpet)
Here spikes are the best solution (3 per speaker).
They couple the speakers tightly to the floor. The resulting system has a higher mass than the speaker alone and thus can better absorb the vibration.
To protect the floor you can get metal washers with the spikes.
A floating floor construction (e.g. wood) or a more traditional wood floor are not as steady but vibrate and resonate more.
Here it is necessary to isolate the speaker from the floor in order to prevent that the floor resonates.
A resonating floor swallows a lot of bass energy.
So the best solution is decoupling the speakers with rubber feet or special anti resonance feet.
Or even better :
Get a stone tile (3 centimetres thick, 30 x 30 centimetres) to add mass to the system.
Put three rubber feet or anti-resonance feet below and put the Speakers with 3 spikes onto the stone base.
My speakers came with casters and my listening room has a glued wooden floor.
I replaced the casters with spikes and washers between spikes and floor.
The bass performance got more precise and lost its booming.
I can recommend to look for the best solution for coupling or decoupling.