Turntable isolation platforms

If you like sand and sugar and things of that nature you might give some consideration to glass micro beads, perfectly round teeny tiny hard glass spheres, the ones sold for use in airport runways, much more suitable to use in isolation stands since they are more easily moved by external forces which is the hallmark of effective isolation - ease of motion. You can put the micro bead box up on cones or springs for an additional stage of isolation. Throw caution to the wind!

Do not want to insult you but I owned aPangea rack and it is nothing great. I moved up to a Solid Steel and it made a big difference. A 4 inch thick solid maple platform with some kind of isolation footers for it to sit on may help. I have 3 platforms, one made from Bubinga wood, one from maple and one granite I am giving away FREE to anyone here.

The caveat is it is pick up ONLY. I live in Rhode Island if there are any takers. The bubinga platform And Granite Platform are large enough for a VPI Prime and the maple platform will fit a Scout.

If anyone is interested in picking one up, send me a PM. I want nothing in return. I want to repeate, I will not ship, local pick up only.

I look at vibration control through an RF impedance matching background. Spiking heavy speakers or platforms improves sound by rejecting high energy bass frequency vibrations in a suspended wood floor moving up into the component or speaker.

Varying pressures in the floor and around supporting beams due to concentrated weight on spikes causes diffraction or reflection of sound, stopping travelling waves in the wood medium moving up the speaker or component. An abrupt change in density is a fraction of bass frequency wavelengths, rejecting sonic conductance which minimizes cross talk between woofers from left to right speaker or speaker to component. Bass frequencies have the most energy and can morph into higher frequency resonance in cabinets and audio racks. 

That is just the start of treatment as I understand it. Performance improves if the fraction of vibration that finds it way up the feet or leaving the feet is attenuated as loss or sound absorption through the use of rubber, sand, isolation feet or platforms - whatever provides wideband absorption of vibration energy.

Basically you want to minimize reflection which is return loss in RF world by matching impedances. That is density and stiffness for maximum sonic conductance of materials. That's how cones work to pull high frequency vibrations out of components. Bass frequencies leaving speakers are best treated with loss through isolation since energy is high and will reverb through the floor. Higher frequency energy will not cause trouble in the floor, but should not be reflected off the isolation footer back into the speaker or component. 

Antenna are tuned or impedance matched for minimum return loss. If we use loss to extend bandwidth and minimize return loss , gain suffers. Fortunately, using loss in vibration control can improve performance with no downside since we are not trying to transmit vibrational energy through the floor at same time.

Miller has it right. Different shelf (atop the sand) will make a difference.

brotw69
I look at vibration control through an RF impedance matching background. Spiking heavy speakers or platforms improves sound by rejecting high energy bass frequency vibrations in a suspended wood floor moving up into the component or speaker.

Varying pressures in the floor and around supporting beams due to concentrated weight on spikes causes diffraction or reflection of sound, stopping travelling waves in the wood medium moving up the speaker or component. An abrupt change in density is a fraction of bass frequency wavelengths, rejecting sonic conductance which minimizes cross talk between woofers from left to right speaker or speaker to component. Bass frequencies have the most energy and can morph into higher frequency resonance in cabinets and audio racks.

That is just the start of treatment as I understand it. Performance improves if the fraction of vibration that finds it way up the feet or leaving the feet is attenuated as loss or sound absorption through the use of rubber, sand, isolation feet or platforms - whatever provides wideband absorption of vibration energy.

>>>>I’m not sure I agree with your detective work. What seems clear is that spikes and cones minimize contact area and reduce the contact with compliant or springy materials like carpets/pads. There are several variables just for cones and spikes, e.g. material, shape.

For traditional mass-on-spring isolation devices we know they function as 🔜 mechanical low pass filters 🔙, 6 dB per octave, preventing or at least reducing the transmission of vibration from the floor to the component. The vibration of concern is both the seismic type - traffic, Earth crust motion, etc. - and speaker mechanical feedback and footfall.