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In the Forum: Analog Playback
In the Thread: Holly Proscenium idiocy!

Post Subject: MkII idiocyPosted by N-set on: 7/20/2013

Making my little research on vibration isolation, I came across those fantastic pictures here
of how Proscenium suspension is made:

http://www.6moons.com/audioreviews/walker9/2.html

I've always thought that he uses some custom-made pneumatics,
but those pictures reveal the thruth: these are just the standard SLM series
pneumatics, with manually trimmed base plate (!) and packed in shiny
cylinders! There is of course nothing wrong in using well proven
industrial solution (I believe such units are in the Vibraplanes, I'll also
employ them in my rack), however one has to know how to use it:
1) the big unit is probably the 300lbs one; why the hell use it here?
pneumatics like to operate at their max capacity for best isolation,
why shooting in owns foot?
2) the pressure in the pneumatics shuold be adjusted to the load: roughly
%max load =%max psi, to keep the resonant point as low as possible.
This is a normal published data (e.g. here http://www.nxtbook.com/nxtbooks/newportcorp/resource2011/#/1110),
so all the "air pressure revelation" is simply a gross ignorance of the manufacturer
and lack of understanding of very basic laws of physics (more air=more stiff=higher fres.)

I don't even want to look into MkIII, IV, V,...
Cheers,
N-set

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