By Wilde Becker. Speaker Stands. At Wednesday, July 24th 2019, 02:10:29 AM.
We tend to think of a loudspeaker as a fixed box that produces sound directly from the moving cones of the speakers (and, where the speaker is ported, from the port as well). Although that is certainly where most of the sound comes from, the reality is that no matter how rigid the cabinet is there will also be some vibration of the cabinet walls.
The theory is that the mass and spring characteristics are chosen so that the resonant frequency of the combination is well below that of any frequency they’re likely to be asked to isolate. For example, if the lowest note a speaker can reproduce is 30Hz, then the resonant frequency of the supporting platform needs to be well below that — perhaps just a few Hertz or less.
It’s physics: for every action, there’s an equal and opposite reaction.