View Full Version : Vibration, horizontal plane? Help, rlw, anyone?
12-27-2002, 10:26 PM
I want to provide isolation for my DVD. Horizontal plane seems to be mentioned alot. I see several options but don't know what I need. Ball Bearing isolation, point isolation, vibrapods which offer horizontal and vertical isolation, weights between isolation points... What the hell do I need???
I'm thinking points transfer unit generated vibration to a higher mass. It's looking to me like I need points on my dvd which sits on a high mass table which is isolated with vibrapods and sits on a non-vibrating shelf. I don't know though. Again, what do I want? I'm pretty lost here but know the right solution will help a lot. Any comments, help or random ideas would be helpful.
Originally posted by madmax001
Any comments, help or random ideas would be helpful.
Every thing has a sound. Whether that sound is perceived by you, in your system, to be beneficial, detrimental, or negligible must be determined by you.
Howz dat for random?
Seriously, though, vibration isolation is a PITA. Why? B/C each device you mentioned - any device - has it's own resonant frequencies, damping properties, etc. That's why it's trial-and-error. The characteristics of a given device might not be what you need.
Reread that Stereophile article I posted a link to - it's worth it.
Think of all the vibration isolation devices like your car's suspension: the job is to both couple and decouple. Points and cones can't magically provide a one-way vibration drain - which is what manufacturers would have you believe - all they can do is somehow change the frequencies which get passed to the device.
I think points/spikes make sense for speakers on carpet with a non-slab floor - especially for full range speakers. They help to couple the cabinet to more rigid structure, decreasing cabinet movement, and improving definition.
Do they help isolate a component on a component rack? No - they might alter the resonant frequency, but that's about it. That might be a pleasing change to your ear - but it might not be.
How much do you want to stimulate the economy?
VibraPlanes isolate in the horizontal and vertical directions - they are engineered precisely for doing so in a controlled manner, they positively work. They're pricey [if you buy from an audio source, figure $5k], they *require* certain setup parameters to be met if they are to function, and they require a source of compressed air. Oh, and they a couple hundred pounds - depending on the model.
Consider the Vistek, Inc. Aurios MIB. This device is more reasonably priced [$300 up], is actually engineered by a company who does good science [the parent company does vibration isolation for things like bridges, electron microscopes, etc.], and you can probably find them on the used market.
I've heard a lot of good things about them, and plan on trying them sometime.
If these are all outside your budget range, I have some PolyCrystal cones [$50/set] that I can lend you to try out. If you like 'em, great, if you don't, well, you didn't waste any coin.
12-29-2002, 01:18 PM
I was wondering if there was a given set of ideas and I think you pointed out to me that there is not. I should have assumed that but I'm finding out a lot of my assumtions over the years are wrong.
One idea you have given me here is that since all components have their own resonances etc which must be dealt with I'm thinking there may be ways to detect some of those attributes. I'm not sure how yet but one thing I've done in the car for bass noises was to connect a sweep generator to the sub and slowly move up the ranges and fix all the things which vibrate as I find them. Maybe some sort of testing can be done for individual components? I'll have to think about that for awhile. The bass analogy for the car is a little rough but hopefully you know what I mean.
I'll re-read that article as well.
12-31-2002, 11:59 AM
Stones 'n Balls (http://www.audioasylum.com/audio/tweaks/messages/71904.html)
01-01-2003, 11:15 PM
I love it. Now I don't have to build that opposing magnet pad I'd been thinking about.
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