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Coupling/Decoupling Electronics

All the posts I’m making are due to my recent purchase of KEF LS50s and my attempts to optimize them. I’m now the first to admit that little changes make a big difference. At 12” from the wall behind then, the bass gets a little muddy. At 13”, I get nice reinforcement without any muddiness. A couple of weeks ago, if you had told me that an inch would make a difference, you’d get a very skeptical look. 

Inevitably, I wandered into the coupling/decoupling, spikes/pads battle. After much reading and a lot of lessons in physics-lite, I have determined that there are too many variables at work—speakers, stands, carpets, floors—for any kind of blanket statement to be made. 

There seems to be less controversy about electronics. The word is: Isolate! Those same speakers that are producing so much vibration are a deleterious force. We must do our best to keep those vibrations away from our finely tuned electronics. 

So here is my question: Don’t electronics produce their own vibration? CDs spin, amplifiers amp. Lots of energy being produced. Like speakers, is isolating them from the world around the right thing to do? Shouldn’t that energy inside the boxes be passed off, as speaker energy is passed off by spikes?


I suspect that, like the speaker question, there’s too many variables at play for a simple answer but I thought I’d ask.


Here’s another, more mystifying question. I just traded up from KEF Q150s. Black ones can be had for $300 from Amazon. White ones—the identical speaker—are out of stock everywhere and cost $5-$600 if you can track down a pair. This seems not to be an example of an efficient market, as Adam Smith might define it. (I’m not complaining. I had white ones.) (And I think that Adam Smith’s ideas are long out of date, having been surpassed by managerial capitalism, advanced capitalism, and whatever is en vogue at this University of Chicago these days.)
paul6001

Showing 2 responses by lowrider57

lowrider57's avatar
lowrider57
5,393 posts
 
They found that the cushioning and the ability to shed energy by rocking back and forth on the pads caused the music to sound lifeless Particularly in the upper registers, if I remember correctly.

Cushioning is exactly what you're doing if you use Sorbethane, it's too soft and pliable. I suppose there may be some benefit by placing it under the stock footers, but there's no benefit when placed directly under the chassis. 
Hard substances such as ceramic DH Cones or BDR Cones will drain vibration.
For decoupling look at Herbies Tenderfeet which are much harder than Sorbethane and rubber. Energy is absorbed and will not be shared with the component like the above materials.
Isoacoustics are excellent at decoupling horizontally and vertically.
@millercarbon can recommend a set of effective springs.

Go to the forum archives and search the many threads on isolation.


lowrider57's avatar
lowrider57
5,393 posts
 
Yes, components do produce their own vibration. Usually the stock footers don’t provide enough isolation and don’t drain vibration from the component. The component can also pick up acoustic energy from the speakers and vibration from the rack/furniture.

Two schools of thought are to either drain vibration into a platform by using cones or spikes placed under the component. The platform is often a hardwood such as maple and is isolated from the shelf. There are many audio racks which have shelves which provide their own isolation.

Or by decoupling; devices are used to isolate the component from it’s environment and also absorb vibration. Decoupling devices include footers that absorb the vibrations, platforms and shelves designed to isolate the component, placing springs underneath, and shock absorber type footers.
This is only an overview of techniques.


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