By Wilde Becker. Speaker Stands. At Tuesday, July 30th 2019, 19:02:49 PM.
Many stands come with a compartment dedicated to sand and similarly heavy and well-damped materials. And there’s method in the madness. You see, the speaker plays music by moving its drive unit in and out to create sound pressure: when the drive unit pushes outwards, it creates sound pressure, but when it moves inwards it pushes the entire speaker backwards.
Subwoofers can be placed directly onto solid floors, but an isolation platform of some type will help clean up the sound if that floor is made of wood or chipboard. It isn’t a good idea to position subs very far from the floor — up to about 150mm shouldn’t present a problem, but more than that and the reflections can start to cause issues.
And, of course, it needs to put the speaker in the correct position relative to the listener, which usually means with the tweeter aimed at an imaginary point just behind the listener’s head. Note, though, that a few speakers are deliberately designed to be aimed directly ahead rather than at the listener, so always check the recommendations in the manual that comes with your particular loudspeaker before directing them inwards.
And stands are especially helpful in the low-frequency area, as this part of the frequency spectrum is omnidirectional and therefore more sensitive to surfaces nearby than the high-frequency area.
Furthermore, in accordance with Newton’s third law of motion (each action has an equal and opposite reaction), whenever the speaker cone moves in one direction it will try to push the speaker cabinet the other way.
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.