By Wilde Becker. Speaker Stands. At Monday, July 29th 2019, 19:31:11 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.
You may have noticed that some speaker stands are fitted with spikes on the base, which help to make a rigid and stable contact with the floor. As long as the stands are both robust and stable, this strategy works well on solid floors, but you may find that it causes problems on wooden floors, due to vibrations from the speaker cabinet being transferred to the floor via the rigid stand and spikes. The floor will then act as the king of soundboards!
One way to improve the situation is to add mass by means of a platform fixed to the top surface of the foam. Primacoustic do this in their Recoil Stabilizer by using a very thick steel slab with rubber matting on top, while Auralex and other companies use MDF topped with dense rubber on their more up–market platforms. IsoAcoustics take yet a different approach, by using a frame made from rigid components joined by resilient isolators.