Tonearm mount on the plinth or on Pillar ?

Halcro
Further expansion of my last question....
Are you saying that, with accoustical excitation, the material will ONLY vibrate if the excitation frequency is the resonant frequency of the material?

IOW. Accoustical excitation at frequencies other than the materials resonant frequency will result in NO vibration in the material, regardless of the energy level of this excitation?

cheers. 

Halcro


"It is only when sound pressure of a sufficient volume (and that's important) at a material's Resonant Frequency occurs...that the material can 'vibrate'."

I want to be sure that I have interpreted your statement here accurately.

What you are saying is this....A material will NOT vibrate as a result of acoustical excitation unless that acoustical excitation is at the resonant frequency of the material and that this acoustical excitation is of sufficient energy.

Is this a correct summation of what you just posted?

Cheers. 

Halcro
accoustic excitation....
firing sound at the material.
putting the material in an environment where sound is present. 

Ok again for clarity.... 

Under circumstances where we fire sound at a material.....
Are you saying that the material will ONLY vibrate at its resonance frequency, assuming that this frequency is present in the sound?
If any other sound frequency is used there will be NO vibration in the material? This with any energy level in the sound?

Yes the capitalized "NO" was deliberate.

Halcro
Can you please explain how we can hear and clearly understand someone talking on the other side of a closed window?
Horrid music, which sounds like a broken washing machine, coming thru the walls of my sons bedroom?

Cheers 

Halcro.

Yep, transmission, WRT vibration, means the same thing here in NZ. 

You mentioned transmission at resonance (FR) and at this frequency, it is obviously at is maximum since the excitation frequency and resonance frequencies are the same. At excitation frequencies below FR, transmissibility approaches 1,  so we more or less get out (vibration) what we put in. At excitation frequencies above FR, we get attenuation (partial isolation} as Geoff has explained above. The further we move above FR the greater the isolation. The curve being asymptotic to zero as the excitation frequency is increased.

It all depends upon the FR of the material or structure, So in your apartment wall example, the FR of the wall is well below the audio band and this fits perfectly with what has been said.... Your excitation frequencies are well above FR so no vibration would be detected.

So we have the question of what is the FR of the structure of the TT or pod? If this falls within the audio band then there is a potential problem.

Maybe a test would be to suspend one of your pods from a thread after removing any damping you have applied. Tap it to ascertain its FR.  

Cheers.