Quiz about adding dense mass to a vibration isolation application!


There are two steps in this quiz:

1) Hypothetically, you have a DAC that is very solidly built on all sides and weighs 25 lbs.

This DAC currently has three Nobsound vibration isolation devices under it, the springs of which are about 50% compacted and are damped by foam ear plugs inserted inside of them.  The vibration isolation effect with this setup is merely middling according to a cell phone seismograph app.

2) You add a 25 lb granite slab to the top of the DAC with a 1/8-inch rubber mat between it and the DAC, and then add the appropriate number of ear plug foam damped springs to each Nobsound device in order to get all Nobsound device springs back to about 50% compacted.

The question: What do you think is the sonic result of step 2?

128x128gladmo

Interesting stuff guys.  @tonywinga ​​​​: What method are you using to measure the resonance in Hz on your components?

A DAC is not a turntable! You could encase it in a block of concrete - no effect upon sound quality! Same thing applies to a digital transport - immune to vibrations. The old analog ideas do not apply! 

The result of being profoundly enamored with one's own thoughts and allegiant to a familiar paradigm is that the underlying pridefulness blocks one from seeing the obvious.

My experience is very different. Vibrations affect everything to some degree. I hear quite a difference isolating my front end components as well as my amplifiers with springs. Granted my DAC and preamps use vacuum tubes but my amps are solid state. I also have experimented with different materials for the boards that the components sit on as well as having them sit directly on the Nobsound feet. I have tried granite (terrible), wood, carbon fiber and HDPE (High Density Polyethylene). Woods work well but I found the HDPE boards seemed to have a slight edge over wood under my preamps.

I have cable elevators too. Unfortunately, I could hear a difference with the cables lifted off of the floor. I made my own cable elevators on the cheap. I used electric fence ceramic isolators supported by rubber bands stretched between two dowels pressed into 4x4 wood boards. Seems to work.

I use the VibrationAnalysis app on my iPad and iPhone. The frequencies are accurate but the magnitudes are for reference only and can only be used for comparative purposes. If I were still working I would be able to compare the magnitudes with a calibrated accelerometer in the lab at work. I know that the FFT analyzer app was dead on with frequency using a calibrated tone from a B&K tone generator but I was not able to verify the magnitudes so they are reference only as well. The iPhone and app work very well and is quite sensitive. Even the lightest of footfalls from several feet away can be detected.