Coupling and decoupling
Traditionally there are two opposite approaches to supporting loudspeakers in situ – coupling or de-coupling. Coupling typically uses metal spikes or cones that hold the loudspeaker rigidly to ensure there is minimal movement and physically connecting the loudspeaker to the floor. It is a misconception that spikes allow energy to travel only one way because the end of the spike is pointed. In fact, just as vibration travels down the spike into the floor, the spike also transmits any floor vibrations back up into the speaker through the same fine point the vibrations have drained through. De-coupling typically uses a compliant material (elastomer, springs, rubber cones, foam etc) that attempts to isolate the speaker from the listening room floor, absorbing some of the vibration. For speakers to work effectively you need to satisfy two seemingly contradictory aims: hold a loudspeaker perfectly rigidly and absorb vibration.