By Wilde Becker. Speaker Stands. At Tuesday, July 30th 2019, 19:03:29 PM.
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.
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.
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.
If the output from the sub seems uneven, you need to try and find a location where it produces a less lumpy response. A good tip for doing this is to temporarily place the sub where you normally sit to mix, and then listen at different places around the edges of the room while playing back a same level chromatic (semitone) scale of sine waves from a sampler until you find the spot that produce the most consistent level across all notes.
An isolation platform works in a similar way to a car’s suspension, and comprises three mechanical components: a spring, a mass supported by the spring, and some form of damping to prevent the sprung mass from continuing to bounce around. In a car you have the springs between the axles and the car body: the car body provides the mass and the shock absorbers provide the damping, to stop you having a bouncy ride.
Thus, the sand provides dampening, but it also prevents the stand from ringing when it’s excited by the right frequencies – another handy little add-on.