Barry, are you suggesting that tons of solid concrete floor(which is directly coupled to the Earth's surface) does not have enough mass to dissipate energy from a subwoofer?
And if you think it does not, then how much amplitude is that several ton solid concrete floor going to generate, when driven by an 18" subwoofer(via the cabinet and spikes, and damped by the entire mass of the planet)? And at what frequencies?
Is not a device like an Audiopoint or Sistrum Platform, which is designed to sink the wideband airborne vibrations to the concrete floor(where they can be dissipated), a better option in this case? After all, they are situated as locally as humanly possible(directly impinging on the cabinet underside, and then directly touching the concrete floor below).
Are you saying that your products can outperform the energy dissipation properties of a massive concrete slab sitting on the entire mass of the Earth itself? Or would it be better to let the natural energy dissipation properties of the Earth do it?
You know, that the neutral connections of your electricity wiring(which feeds all the power to your audio system) is attached to an earth ground that easily and hungrily soaks up all that power running your gear(including the sub), and has the capacity to soak up much much more.
According to the 2nd Law of Thermodynamics, ALL ENERGY(not just electrical) seeks the ground state via the path of least resistance. Certainly you realize this, yet you promote the interruption of this "path of least resistance" in all your designs, preferring instead to substitute a smaller piece of "earth", or a very small bit of flexible material(subject to very easy overload, which reflects all it cannot absorb back into the nearest boundary - the component, as the Zener Viscoelastic model tells us) to do the job.
We obviously differ on the most efficient methods used to manage the vibrational energies present with audio equipment.
I agree that a "very live and flexing floor" could lead to difficulties, but the floor is being driven by airborne vibrations(sound pressure waves) primarily, and only much less-so by the bottom of the speaker cabinet. Our suggestion for those cases would be to address the issues with the unstable floor, and not to interfere with the performance of the audio system that sits on it. This may not be as easy as buying small pieces of rubber and putting it under the speaker, but it is much more effective in curing the problems of an unstable floor. A flexing wood floor is much like an acoustic guitar(which I custom build in my spare time). There is a direct coupling of the strings to the top via the bridge. If the top of the guitar is responsive(flexible), it will produce strong amplitudes of sound vibrations with wide frequency response. If the top of the guitar is overbraced and stiff, it will be "dead" because it cannot move with any significant amplitude, even when driven, and since in the case of the guitar, there is no route to ground, the vibrations basically remain primarily in the strings(although some vibrations are damped in the wood mass) and dissipate there in the classic air-damped string decay pattern.
In my home situation, I have to deal with a typical suspended wood floor all the time. When playing at 105db peaks, I have no problems with vibrations "re-entering" my system from floorborne vibrations. I situate my equipment near the wall that has the foundation under the edge of the floor, which is a node, and doesn't get into large amplitudes. I also have concrete piers under the center of the floor, to keep it from going into any noticable amplitudes by terminating the center of the area of peak oscillation amplitude(the center). This "center node" is at my listening position, and doubles the frequency and halves the amplitudes of any previous(unsupported) floorborne vibrations. This simple form of bracing can control the development of any significant amplitudes that may be driven by either airborne sound-pressure vibration or speaker-bottom driven vibration, because since it is more difficult now to drive the floor into oscillation, the easiest path becomes routing to the earth.
Maybe not everyone can do this, and maybe most don't want to be bothered to do it. In these cases, it is easier for them to compromise, and typically that is what is done. In most construction, the structure is of sufficient rigidity to bear out this concept, and certainly concrete floors are.
