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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 (And I think that Adam Smith’s ideas are long out of date, having been surpassed by managerial capitalism, advanced capitalism, and whatever is en vogue at this University of Chicago these days.)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
lowrider57's avatar
lowrider57
5,417 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.


cd318
2,636 posts
 
Sorbothane hemi-spheres under my Tannoy Berkeley's (4x 50 duro for 35kg) enhanced the bass / mid-bass of my speakers. 

That in itself seemed to marginally clear up the entire frequency range.

As far as I could tell there were only gains, no losses.

Springs might be even better, but are not really practical in their current domestic location.
mahgister's avatar
mahgister
13,091 posts
 
Sorbothane hemi-spheres under my Tannoy Berkeley’s (4x 50 duro for 35kg) enhanced the bass / mid-bass of my speakers.
In my experience with sorbothane, i advise you one day to try instead duro 70.... Select the right hemisphere diameter for the weight of your speakers but take duro 70.... It will be better for sound i am pretty sure, i use them for all my headphones damping and duro 70 was surprizingly the better to damp the sound because of his higher density....😊 Wait a year and replace them... Anyway the sorbothane material suffer fatigue with time.... It is a good idea to replace it one or 2 years apart especially under heavy load....I dont use my 7 headphones at all they are way less good than my speakers now.... Thanks to my embeddings controls....

Springs indeed would be better but it is not always possible because of some unstability ....In a living room i could never use them save at risk from children or even adult accident.... My speakers are even on heavy damping load .... Results are amazing but stability is good only not ultra safe....But anyway it is in my audio room and all is ok here...even my wife knock at the door and my grand children were even fearful of my audio room at first, now everyone is fascinated by my "madness" and my high quality sound also tough....

😊😁😊😎😊😉


antigrunge2
1,415 posts
 
Spikes on concrete are one thing, on wooden floora thy are something else, namely useless because of the unwanted resonances they create. On the latter damping is necessary. I have used Black Ravioli and Symposium Svelteshelf, the latter having a less dampening impact on trebble performance given the intermediate metal layer.

paul6001 OP
98 posts
 
And the OP makes his final statement:


When I first got my new (used) LS50s, I plunked them down on the stands where the old speakers used to stand. They sounded great. 

Since then I’ve tried every tweak possible including moving them 1/4 inch in every possible direction, putting pennies under the spikes, using sorbothane pads under the feet of the electronics, turning the speakers to face Mecca, on and on. 

Nothing worked. I’m quite relieved that removing the sorbothane brought the life back to the system that had so completely been removed. Once again, Morrissey sounds like Morrissey. So much thought, so much work, so many posts only to realize that everything—EVERYTHING—I had been monkeying around with was only doing harm. 

It was all fun, in a certain sense, but the bottom line is that NAD knows what they’re doing. If their stuff sounded better on mushy feet, they would have put it on mushy feet. If I had bought a Ferrari, would I have spent two weeks trying to outdo the Ferrari mechanics? Probably. But I’m sure that I would have learned the same lesson that I just did: Let the pros do their thing then sit back and enjoy what I just spent all that money on. If I wanted to tinker, I should have bought one of those kits from Radio Shack.
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