Vibration Theory - Isolate or Drain?


Given that a CD Player or Transport has quite a bit of internally generated energy from the motor, is it best ti deal with vibration issues by coupling the player to a surface with spikes or cones? or decouple the player from the surface beneath it with spongy materials? Any consensus on the best approach here?
pubul57
Placing my friend's TT directly on the rack, it played fine. Putting cones under certainly seemed to improve the sound. Flipping them upside down, putting the cones 'point up' caused it to mistrack on some passages. This, to me, suggests "draining" does occur. By the way, the cones were short, wide and made of aluminum.
There are two sources of vibration: Internally generated, and externally generated (sound). I would think that using something like sorbothane would isolate. But what about vibration from a component itself, or picked up from sound waves?
How about both approaches? Cones under a component that has damping pads/and or weight, sitting on or "draining into" a platform that absorbs and is sitting on sorbothane feet to isolate.
Someday I plan on trying something like this under my TT.
I sometimes wonder why I don't simply don't trust Ed Meitner to know what kind of feet to put on his players for good performance - the latest generation does appear to have given some more serious thought to design of the footers. Which did not stop me from putting 3 brass pucks, with a Sorbathane layer, on top of the player for mass loading and Herbie's Tenderfeet underneath. Not sure it improves anything as it is a pretty solid player to begin with, but it looks nice and wasn't too expensive. I get the sense that for every isolationist there will be an equally vociferous drainer - both with "happy" results.
OK, I support the info from Mapleshade. You drain from the top and you don't stop till you get to the bottom. Every component, every shelf has to work to drain the vibration from the whole and into the floor or you defeat the benefit. If you like putting weight on top of the components that's fine but it won't give you the full benefit unless you drain what's been created by the system components.

One of the best tweaks I've used for my tone arm are the Nano Mounts and record clamp system from Mapleshade. It's not easy to put micro sized triple points between the cartridge and tonearm and also the tonearm base and arm board but it is defitely worth it (this is draining). And by the way, loosen the screws on your cartridge till they just barely tighten the cart to tonearm. They really don't need to torqued to stay in place and it deadens the sound. And get some brass screws too.
I use OHAUS brass weights on top of all 4 players in my system. The weights are 20g(2),50g(1),100g(1). For what ever reason the brass weights work best in my system on the front right(3 players) and front left(1 player) of the units. One odd finding is that on all 4 players they work best on the front opposite side of the units power cord. Example: 3 of my players have power cords on the back left of the unit. On those players the brass weights sound best on the front right. It is just the opposite with the one player that has the power cord on the back right of the player. The brass weight sounds best on the front left. Don't know if this just a coincidence. But it is consistent with all my players. I know what some of you are thinking, what would happen if my power cord was dead center in the back of my unit, would it go both ways?
Your tiny electronic vibrations in your player likely isn't going to be in a frequency you can hear, but I doubt that would convince you. The science behind coupling is to make the entire system as heavy as possible -- with more mass, the resonant frequency lowers. This should actually be harmful on your audio rack unless your rack is weighed down with a hundred pounds of sand (think metal speaker stands) if the resonant frequency is within audible range.

Decoupling -- viscoelastic material such as sorbothane actually absorbs some of these vibrations and turn them into heat. This is mechanical engineering 101, for more info, look up the "spring-dashpot" model.

I think in the medical, HVAC, etc. industries where vibration must be stopped to reduce noise or because of sensitive equipment, decoupling is most likely to be used. Coupling will pass vibrations onto other components where it will be harder to control; the idea is the control vibrations at the source, and that means using springs and hydraulic shocks in the worst cases to turn as much vibration into heat as possible.