Spikes versus wall coupling

A properly designed point or spike will provide a geometric path way for resonant energy to exit thru the point and into the larger mass it is direct coupled with. There are discs on the market which when placed under the coupling point increase the surface area of the point and provide surface protection of wooden materials. Your wooden floor is much more massive than your speaker so you should direct couple your Polks. The force generated by the massive radiator will only modulate the cabinet over and over again unless the speaker is properly grounded or coupled to the floor..Tom

Thanks you all for your input. I get the impression that it has never been fully settled whether it is better to isolate or couple speakers. Am I correct that here are two schools of thought? Is the same true for components (some folks isolate and some couple :)

Tom, If you want to couple speakers as massive as these to the floor why would you need to do anything except let the wood bottom rest unobstructed to the wood floor? That would certainly allow all of the vibrations to pass directly to the floor. In fact I think a case can be made for the proposition that if you insert an intervening devise you might successfully limit the vibrations that may be transmitted from the speaker cabinet to the floor to those vibrations that the intervening devise can pass. Assuming that the devise is not limiting, how exactly will it improve the direct contact of the bottom of the speaker?

One last question, once you have all of the vibrations being transmitted to the wood floor, if you have similar devises under your TT and equipment racks how to you keep the vibrations from going up into the TT and other sensitive components in you rack? Or do the vibrations only flow in one direction?

Hi Newbee,

You are quite correct. Coupling one of the main sources of vibration (the speaker) to the floor will allow that unwanted energy to travel towards the components. If they are also coupled to the floor (by rigid points, rigid spikes, a slab of rigid stone or rigid wood) the vibration will travel up into the bottom of the component. Any rigid device allows vibration to travel in BOTH directions - down out of the component AND up into the component.

In the case of speakers, if you rigidly couple them to the floor they will also be subjected to external sources of displacement (vibration) such as exterior traffic (trucks, autos, busses, airplanes, trains, freeways) and natural geological seismic activity. That will negatively affect their performance.

Best Regards,

Barry Kohan

I am a manufacturer of vibration control products.

I'm a relative newcomer to to this, so if I am coming from left field, forgive my ignorance. They are many materials, polyurethanes and foams for dampening vibrations and absorbing sound. Wouldn't using some of these things work? Sorbothane absorbs shock and vibration very well. It is an expensive material, $105 for a 1/4"x24"x24" sheet, but it seems it would be very effective in dampening vibrations coming off of a speaker and stop vibrations going to a speaker, CD player, turntable, etc., etc. etc. There are sound absorbing panels and vibration damping coatings that you can apply like paint to ventellation ducts and sound/vibration dampening panels that could be used under the flooring to improve the overall accoustics of a room. I looked in the McMaster-Carr catalogue and found a lot of sound and vibration control stuff that seemed would be perfect for tuning a room or controling unwanted vibrations and sound. Why not use some of these materials? Am I all wrong on this?