Given enough energy, sound will travel through anything. Just stand outside a night club and you can hear the bass travel right through the walls. This occurs when the source of the sound vibrates and the vibrations, if sufficiently strong, will couple through the air or through the device itself, the floor and substructure which will cause the following device to also vibrate and emit sound.
In the studio it is no different. Sound from a near field monitor will vibrate through to the shelf or desk on which it is resting. This will cause the shelf to vibrate. The size and mass of the shelf will determine the frequency at which this will occur. If the frequency being generated is in phase with the loudspeaker, then this frequency will rise in amplitude. If the two sounds are out of phase with each other, then a cancellation will occur. This not only happens at the fundamental frequency, but will also occur at related harmonics. The effect is commonly known as comb-filtering.
By insulating the loudspeaker from the shelf, you can eliminate the coupling which causes the problem. This is precisely what the IsoWedge and IsoPlane are designed to do. They effectively decouple the monitor which in turn brings greater clarity to the loudspeaker. The energy in fact will be dissipated into heat via a process called thermo-dynamic transfer.
Critical to the performance is the quality of the acoustic foam and the thickness. It is critical that the acoustic foam be sufficiently dense to ensure the loudspeaker properly ‘floats’ without coupling into the shelf. If the foam is too thin, the bass frequencies will merely jump across the boundary therefore using a thin layer of foam will have little or no effect.
The IsoWedge and IsoPlane have been specifically design to provide sufficient space between the loudspeaker and the shelf to ensure these are decoupled and the high density open cell acoustic foam is custom ‘baked’ to achieve the desired stiffness. Once in place, these will bring greater clarity to the mix, thus making it easier to get the job done.