Sound Deadening Material For Vibration Control
Posted 28 January 2014 - 09:12 PM
Posted 28 January 2014 - 09:36 PM
Posted 29 January 2014 - 12:56 AM
Posted 29 January 2014 - 03:29 PM
Posted 29 January 2014 - 06:22 PM
Posted 29 January 2014 - 06:29 PM
I initially consider fine sand, but the pier & mount were heavy enough already! Spray-in foam? That's probably an even better solution - maybe it would help prevent rust, too.
Posted 29 January 2014 - 06:33 PM
Posted 29 January 2014 - 06:41 PM
Posted 29 January 2014 - 10:00 PM
Posted 29 January 2014 - 10:06 PM
Posted 30 January 2014 - 01:10 PM
I lined a pier with dynamat extreme and it did not work nearly as well as I thought it would. I think the problem is that this material is designed primarily to kill long wave low level vibrations coming into the car from the road and tires, so you hear your audio system better. It also prevents rattles in the car panels from the subwoofer. So it works great in my car, but I don't think it does much to kill short wave vibrations and I believe those are the kind of waves that are the main problem with telescope mounts.
Your car dampens the big, honking, violent vibrations of 3,000 pounds hitting a bump at highway speeds. At the scope, the trouble is the fast, little, gentle, but annoying vibrations of your nose tapping the eyepiece.
Posted 30 January 2014 - 04:06 PM
Posted 30 January 2014 - 04:31 PM
Posted 30 January 2014 - 06:38 PM
Stiffness damps vibration, usually higher frequency vibration by means of "scattering" its energy through multiple paths that statistically are destructive in interference. The paths come from geometrically diverse fibers or foam bubble contacts, the less elastic the better.
The "roll off" of this frequency is due to the size of the column. For low frequency in a column to be damped, it must be absorbed in the axial direction of the acoustic wave by a damping force. An example would be a column of a viscous substance (like oil which is heavy). In this case, the energy is in effect "refracted" in place by the substance.
Posted 30 January 2014 - 06:44 PM