By Wilde Becker. Speaker Stands. At Sunday, July 28th 2019, 20:08:39 PM.
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.
A speaker platform is designed primarily to provide a degree of mechanical isolation between the speaker and the surface upon which it is placed, while keeping the speaker firmly in place. This is particularly important when siting speakers on lightweight desks or shelves, as these can easily be set into vibration if in direct contact with a speaker cabinet.
That’s where you need to put the sub. If your sub has a phase adjustment knob, or a polarity–invert switch, adjust this until you hear the loudest result from frequencies around the crossover point, typically 80 to 120 Hz.