First thing is, you can't "isolate" the speakers. The speakers are a strongly vibrating component, and they cannot be isolated from themselves, ever. If you think the cabinets are "dead", the driver baskets and cones are vibrating like mad anyway.
The ONLY way to deal with a situation like this is by a well engineered vibration drain system such as the Sistrum speaker platforms, or the Audiopoints. I have tried both, and the Sistrum platforms exceed the Audiopoints, in terms of performance. They should, because they are the next step up, and they cost more than the Audiopoints. But they are significantly better.
ANY soft type of material like rubber blocks or the like, will allow slight movement of the speaker in a fore/aft axis, thereby smearing attack and dynamics and coherence by doppler. They will also eliminate the path for vibrations to exit, and they are doomed to circulate and re-circulate in the speaker.
I have a suspended floor, and the Sistrum Platforms and Audiopoints have made a remarkable improvment in sound, especially in the speakers.
Another interesting benefit, is that you get another db or two efficiency out of your speakers, because they are operating in a more efficient mode, when the vibrations are properly removed from the motor. This is not a joke, or exaggeration. This is a real increase in speaker efficiency, and I have experienced it for myself.
The ONLY way to deal with a situation like this is by a well engineered vibration drain system such as the Sistrum speaker platforms, or the Audiopoints. I have tried both, and the Sistrum platforms exceed the Audiopoints, in terms of performance. They should, because they are the next step up, and they cost more than the Audiopoints. But they are significantly better.
ANY soft type of material like rubber blocks or the like, will allow slight movement of the speaker in a fore/aft axis, thereby smearing attack and dynamics and coherence by doppler. They will also eliminate the path for vibrations to exit, and they are doomed to circulate and re-circulate in the speaker.
I have a suspended floor, and the Sistrum Platforms and Audiopoints have made a remarkable improvment in sound, especially in the speakers.
Another interesting benefit, is that you get another db or two efficiency out of your speakers, because they are operating in a more efficient mode, when the vibrations are properly removed from the motor. This is not a joke, or exaggeration. This is a real increase in speaker efficiency, and I have experienced it for myself.