GoodSoundClub - Romy the Cat's Audio Site

In the Forum: Audio Discussions
In the Thread: Mastodont DIY Rack: Wall Mount?

Post Subject: More logicPosted by decoud on: 12/5/2013

N-Set, I do not claim to add to the facts you have already comprehensively given, I am merely asking about the logic, and I do not suggest to have a definitive answer, hence my ending with a question. I can see three reasons why other people use spikes: 1) for stability against rocking on the base 2) for where there are spatially distributed differences in the amplitude of the floor vibration so that one might thus find a local minimum and, most of all, 3) where vibration of items *on the rack* needs to be damped by coupling to a less vibrating floor. None of these seems to apply in your case because you have a properly levelled installation, directly on concrete and the vibration to be damped is mostly external. But in any event what people do is no guide to the science, which is what we are talking about here, and as you say you do not see optical tables with spikes.
I see the issue with double compliance, but this is the point about the nature of the vibration: for resonance to become an issue here the vibration has to be more or less stationary, no? And the kind of vibration you need to deal with here is mostly non-stationary (unless your neighbour's washing machine gets stuck in a spin cycle). So what is more important is increasing the damping, which can only be a matter of energy absorption. Mass damping stores it, friction damping dissipates it: so better to increase the friction component than the mass, no?

Rerurn to Romy the Cat's Site