[Puma Cat]

So...I spent yesterday afternoon doing some more audio rack shelf/maple board and footer studies using VibSensor and JMP14.

Here's a plot comparing just the vibration in the top shelf of my Sanus Euro II audio rack without my DAC on it, just to get a baseline.

The blue trace is just the audio rack top shelf by itself; the iphone is resting along the right edge of the shelf so that its mass does not damp (not dampen, which is to make something moist) the imparted Power, RMS. The Green trace is the maple board sitting on 3/4" wooden blocks with the phone resting on its edge, and the red trace are the Diversitech closed cell foam & rubber anti-vibration pads (DVT AVP) under the maple board. Note that the imparted force using the DVT AVPs is much higher, and is shifted up about 10-15 Hz into the 40-50 Hz range.



Conclusion:
My guess is that the AVPs, being made of rubber and foam, are acting like a undamped spring on a car; amplifying the imparted vibration. As there's no "damper" (i.e., like a car or bike shock absorber), the AVP actually makes the amplitude and the frequency of the imparted power (vibration) worse.

This result, interestingly, is consistent with my DOE from the other day, where I found that less power was induced into my DAC with it resting on the audio rack shelf on Herbie's Tenderfeet (TF) than on the maple board with TF and AVPs.