Published at Wednesday, July 31st 2019, 07:41:31 AM. Speaker Stands. By Hardtman Fuchs.
One of the roles of an effective speaker support is to prevent such vibrations from being transferred into other structures, such as wooden floors, desktops, shelves or mixer meterbridges. It should also hold the speaker as firmly as possible, to reduce movement due to the action/reaction effect.
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 cheap DIY option is to build a couple of towers by stacking concrete blocks or bricks. This low–cost approach really works — we’ve used it successfully on more than one Studio SOS visit — and because of the high mass, very little vibrational energy makes it through to the floor. Some people like the rugged appearance of bricks, but if it’s not to your taste you can always disguise them with cloth drapes, or even spray them gold if you like that kind of thing!
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.
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.
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.
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.