kingbarbuda14 posts03-17-2019 9:40pm**Leaving to ask what would be the incremental benefit of *any* expensive vibration resolution solutions.
>>>>>Generally, the two determining factors for isolation device performance are resonant frequency Fr of the iso device and number of directions of isolation (degrees of freedom). Thus, the spring rate of the spring should be as low as possible for a given weight of the component. Very Stiff Springs 🏋🏻♂️ must obviously be used under very heavy amps, speakers and turntables, otherwise the component will topple over due to insufficient lateral support.
As I already pointed out a Fr of 5 Hz will result in transmission of 90% of vibrations with frequency of 10 Hz, whereas if the Fr can be reduced to 2 Hz the percentage of transmission for 10 Hz vibration can be reduced to 50%. The low pass filter characteristics of mass on spring isolators provide very low transmissibility for frequencies greater than 20 Hz. But obviously there’s an incentive for trying to achieve very low Fr. My Nimbus Sub Hertz Platform was the first audiophile iso stand to provide six degree of freedom isolation. By contrast, most audiophile iso stands provide one or two directions of isolation, the vertical direction 🔝 and horizontal plane 🔛.
There are six directions of motion for any object, including three rotational directions around the x,y, z axes, respectively. Forces in rotational directions are usually caused by Earth crust motion that is analogous to shaking out a carpet or a wave 🌊 passing under a boat 🚣♀️.Thus, the ideal vibration isolator addresses all 6 directions. But the more directions addressed by an isolator the greater the complexity and cost, generally speaking. A combination of mass-on-spring isolators and roller bearing assemblies can provide isolation in most of the six directions, for example.
There are additional factors involved in effective vibration isolation, such as method of mounting the component on the top plate of the iso stand, method of mounting the iso stand on the floor or rack, and method of reducing “residual vibration” on the top plate of the iso stand. The geometry of the spring or airspring is yet another variable. A bicycle 🚲inner tube, for example, has a very non-ideal geometry. And the airspring used in my Nimbus Sub Hertz Platform had ideal geometry, whereas the air bladders used in some iso devices are not at all ideal geometry-wise.
