Sorbothane pads / feet

[Blackmorec]

If sorbothane works for you under a component its because it has a less deleterious effect than whatever your component was standing on before. but sorbothane is nothing like transparent or neutral. It will colour your sound and rob it of ultimate pace,  rhythm, timing, propulsion, swing and energy. It will also tend to muddy bass and remove high end sparkle. 

Sorbothane does a superb job in isolating certain frequencies, but unfortunately not all. Also, it isolates in both directions, preventing external vibration reaching the component, but equally well preventing internally generated vibration from leaving the component. 

If you are looking to get the ultimate results from your stereo, sorbothane is not for you. If you are looking for a nice, cheap improvement to enhance your sideboard or wooden shelf, go for it. 

 

Ideally, if you are after highest SQ, what you want is a footer, shelf or rack that isolates external vibration and grounds internal vibration, converting it to work and heat.  Well engineered constrained layer damping is one of science’s answers to the problem. 

[Blackmorec]

3 hours ago, Ralf11 said:

I am at a loss in trying to determine the mechanism by which your last para. makes sense.

 

CLD is hardly anisotropic

CLD doesn’t need to be anisotropic.

 

Sorbothane isolates, so external vibration is kept out of the component (good) and internal vibration is kept in the component (bad)

 

CLD works based on shear strain in the damping layer, which converts both external and internal vibration into latent heat instead of transmitting or reflecting it.  In this way external vibration and internal vibration are dealt with in exactly the same manner.......the component is thus isolated from external vibration (good) and internal vibration is drained from the component into the CLD’s damping layer (good)

 

 

[Blackmorec]

13 hours ago, fas42 said:

What's anisotropic got to do with anything? - both Sorbothane and CLD use viscoelastic behaviour to convert vibration into heat - they damp oscillation. So, both are good ...

Anisotropic doesn't come into it.

 

Basically, sorbothane and CLD are very different in their structure, properties and function.

 

Vibration is bad for electronic components. External vibration coming from loudspeakers for example should be kept away from electronic components and internal vibration coming from transformers, transports etc. are best drained out of and away from components instead of bouncing around and reflecting internally.

 

For vibrations to transfer efficiently from 1 material to another,  the resonant frequencies of each material should be quite close, so the vibrations encounter a low impedance interface. When the interface impedance is high (big gap in the resonant frequencies) vibrations have a very tough time crossing it. Sorbothane makes for a very high impedance interface with items like hard and stiff shelving or metal component cases, so very little vibrational energy is transferred. This is great for external vibrations as they remain isolated in the shelf and cannot transfer into the component. Perfect!. The sorbothane isolates the component. But in the opposite direction, again due to high impedance, sorbothane will not transfer internal vibrations out of the component very efficiently and isolates them in the component.  Not perfect at all!

 

Constrained layer damping is very different. It comprises two stiff outer layers bonded sandwich-wise to an internal visco-elastic layer. The outer layers' resonant frequencies are close to the shelving and component cases RFs so both external and internal vibration easily cross the interfaces into the CLD's outer layers. The outer layers are bonded to the visco-elastic inner layer so when the outer layer vibrates, it tries to pull the visco-elastic layer with it, but the other side of the visco-elastic layer is bonded to the second outer layer, which is not vibrating. This creates shear forces, which is work, which in turn generates heat. The energy from both internal and external vibration is thereby converted into thermal energy in the visco-elastic layer and thus dissipated.