Dampening by air cushion only

[Markus]

I am still betting the head and damper are coming into very slight contact as i know its not odd for a drum head to oscillate at least a few millimeters.

great puzzle!

To see there's no contact please try it on your own with just your hand, the effect is well audible.

as i know its not odd for a drum head to oscillate at least a few millimeters.

The head vibrates at different levels of displacement, highest in the center, lowest towards the rims, which is where the damper sits. Also vibration means positive and negative displacement, so to reach 2mm above the head it in fact has to move 4mm.

great puzzle!

 

[Otto]

" Also vibration means positive and negative displacement, so to reach 2mm above the head it in fact has to move 4mm."

Agreed...traversion i noticed ranged from 1/4 inch(1/2 phase) to couple mm(also 1/2 phase) based on how tight the head was...and much further for cymbals which really surprised me

 

[cbphoto]

I still think it has to do with air pressure between the head and the damper

Increase the surface area of the damper. Add an energy absorption fabric (I'd try neoprene).

 

[wildbill]

Seems like higher pressure would produce a higher pitch.