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To couple or decouple? That is the question.

This is one of my favorite subjects and pet peeves.Is this just a matter of semantics or a misrepresentation of the principles applied in the set-up of equipment. My experience tells me that coupling is what you work for. This is the principle that is expoused in the early Linn literature. The mechanical connection that doesn't introduce or take away any information. This seems important with componets with transducers primarily turntables and speakers. Different materials, like sorbothane, are used to attenuate frequencies but are used in conjunction with metal cups to physically couple to your stand, shelf, floor, etc. Coupling also allows mechanical/acoustical energy to travel away from a componet. The designers at Mission in the early 80's were right on to this. Questions or comments please.
rickmac
phowell1
3 posts
 
The best situation is when vibration has an easier time travelling in one direction and a harder time in the other. This should be the case when you use spikes under your equipment. The reason, I believe, is that you are creating a situation where there is low physical impedance from your equipment to the table, as the small surface area of the tip creates high effective mass (by making your equipment seem much heavier to the table). There is then high physical impedance for vibrations going from the table to the equipment, as these vibrations now have to travel up into what seems like a heavier object.
tbg
5,263 posts
 
I grow tired of this techno-babble. True coupling would be to run a long I beam below your equipment into bedrock. This would add the mass of that bedrock to your system mass. There is no real isolation as everything you use has a resonant frequency and your choice is where you want it. This is true for air and magnetic isolation also. In fact coupling is also isolation but with a very low resonant frequency.

Most of my equipment is coupled to my wooden floor, but my speakers have a soft cushion between spikes below and above. My experience is that you need to try both solutions and choose what is best sounding.
nrchy's avatar
nrchy
2,111 posts
 
Tbg, that is why people are beginning to build stands built for certain resonant frequencies. The designs are made so that the bases resonant frequency is below that of the gear on it. If the resonant frequency of the base is below that of the gear placed upon it, the gear cannot resonate.
tbg
5,263 posts
 
Unless it is generating the movement and assuming it is tightly coupled to the stand. I do like the Neuance shelves on my Mana stands, however, as they have continuously variable resonance frequencies and are on the Mana spikes.
psychicanimal
1,738 posts
 
Words of wisdom:

True coupling would be to run a long I beam below your equipment into bedrock. This would add the mass of that bedrock to your system mass. There is no real isolation as everything you use has a resonant frequency and your choice is where you want it. This is true for air and magnetic isolation also. In fact coupling is also isolation but with a very low resonant frequency.

I wonder what the Sistrum cult followers have to say...
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