Published at Wednesday, July 31st 2019, 07:41:34 AM. Speaker Stands. By Edsel Zimmermann.
Even if you already have a loudspeaker stand, you can still use one of these foam–based speaker platforms on top of it to reduce the amount of vibration getting into the stand and subsequently into the floor. Many of the commercially available platforms come with additional foam wedges that may be used to adjust the vertical angle of the speaker if necessary.
No, it’s not because we don’t like your bookshelf. It’s probably really good looking. But, bookshelves, sideboards, TV-boards and tables all share a common drawback: surfaces. You don’t want surfaces close to your speakers, as surfaces can cause early reflections that colour and distort the sound image – that’s also why we recommend getting your speakers away from corners and walls.
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.
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.
Their smaller stands are made from a type of plastic and their larger ones from cast metal. All are perfectly valid approaches. Note that some speakers, such as certain Genelec models and Event’s Opals, already come with resilient isolating platforms or feet and so may not need additional treatment.
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.
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.