Newbee, you raise an interesting point which I think is long overdue for discussion:
There are absolutely no vibrations or "resonances" to be DRAINED from a loudspeaker. And if there are, then its cabinet/enclosure (or stand) is poorly designed.
The object of using spikes/cones under speakers (as opposed to components) is to "mass-couple" the speaker to the ground. "Mass-couple" is just a fancy term for "hold it down tight!" and steel tie-downs with big bolts would work great too, if you didn't mind looking at them.
The only thing that should move/vibrate in a loudspeaker is the transducer(s) itself -- and 99% of those only move forward and backward. And the only thing the transducer should impart its vibrations to is the air -- not the cabinet, or the stand, or the floor.
With components, especially turntables, transports, and amps (because of tubes and especially transformers) it can be desireable to "drain off" micro-vibrations thru a mechanical "diode" like cones, or ball bearings, etc. But speakers do not require this. With loudspeakers, the use of cones and spikes is merely a way of securing the cabinet (or frame, in the case of electrostats) to the ground so that ALL the energy of the transducers is transferred to the air, and none to the cabinet, floor, etc.