why spikes under speakers???

could you guys educate me about the use or need for spikes under speakers, it seems to me that putting an air pocket under a speaker would be the last thing you want to do, isnt bas about pressure? and if you put a gap of air between speakers and floor arent you losing some of what makes bass work? I am not claiming this to be bad, I simply want to pose my questions about this concept and get educated on why this is a good idea, and when it may not be a good idea...thanks

Thanks again. Your explanation answers my questions, and raises others! (that's a good thing!).
I honestly think that we haven't scratched the surface as far as vibration control of audio components goes. I've read some theory from Michael Green and find some of his opinion pretty radical but at the same time quite thought evoking, as yours are.

I'll follow your threads with interest.

TWL, without disputing the benefits of spikes, whether it be for isolating or "draining" and I do believe that there are benefits in using spikes, I must take you to task for mis-using the 2nd law of thermodynamics as the explanation for the "vibration" draining effect.
The 2nd law does not refer to any energy going to ground through the path of least resistance.
As quoted from the Perry Handbook, the 2nd Law is "The Entropy change of any system and its surroundings, considered together, resulting from any process is positive and approaches a limiting value of zero for any process that approaches reversibility."

The second law requires that the entropy of an isolated system must either increase or in the limit, where the system has reached an equilibrium state (the vibrating speaker system, isolated by the spikes), remain constant. The vibrations are converted to heat.
For a closed but not isolated system (the vibrating speaker system tightly connected to another mass or floor),it (the 2nd law)requires that any entropy decrease in either the system or its surroundings be more than compensated by an entropy increase in the other part.

The short of it. Energy tends to goes to its lowest expression of it. Heat (Entropy) is the lowest level of energy. For an isolated system (suspended speakers is as close as one could get, I guess) the vibrations are converted to heat through absorption in the speaker systems mass. If the speaker system is not completely isolated some of the vibration is also absorbed by the attached mass.

Even if one uses the "vibration draining" description for an explanation and I can see where this is an attractive explanation for the non-technical person, the use of the 2nd law as the explanation for the draining of vibrations to ground is stretching an analogy too far.

I feel that the benefits that we derive from spikes is that we isolate the speaker system from the floor and keep the floor from vibrating because of the speaker. A vibrating floor definitely doesn't help with the speaker's perceived performance. There are enough things vibrating in the listening room from airborne vibrations, without having to deal with direct excitation of the room surfaces by the vibrating speaker system. This also has the benefit of not exciting some of the sources (turntable) which can be affected negatively from outside vibrations. Sooner or later, the cartridge/arm has to be protected from outside vibrations.

I respectfully submit that the engineers with whom you work probably used the "drain to ground" analogy because they wanted to somehow explain the benefits to a non-technical person. They have, I believe, underestimated your intelligence and knowledge from what I have gleaned from your excellent posts on turntable and arm performance.

With respect,

Bob P.
First Law....You can't win.

Second Law...You can't break even.

Vibration must be converted to heat in some damping medium. If you "drain" vibration to the earth, you are contributing to global warming. Shame!
I have to stop you fellows.

Spikes "do not" drain anything. They simply act as mechanical couplers.

If a speaker is "reacting" to its drivers by vibrating, then the spikes will couple the cabinet with the larger mass (the floor) and reduce the reaction from the drivers, by adding that mass.

It is that simple. All this mumbo jumbo about shape of the cone, and metallurgy and such is "mish mash".

Spikes are NOT Drains, for they don't "drain" anything.

They simply make it more difficult for the drivers to have a reactive (force) effect on the cabinet.

These long thermodynamic answers are making me dizzy, their so full of mis-information and mis-interpretation.