2. tech-talk
  3. 1232492162

Racquetball isolation platform perfection

Racquetball isolation platform perfection ... and DIY style to boot ! Thought I'd share with you my experiment that turned out working perfectly in my system.
Basically I copied a Ginko Cloud platform using $5 worth of racquetballs from Wal Mart and some 1/2" Birch plywood. I used a specialty grinding stone from a local tool store that makes a perfect 1.5" concave in the wood. Cinched it up in my drill press and drilled it down about 1.5" in from every corner, and went down about 3/8" deep. It's allows the balls to move back and forth by about a half inch, and when the top platform is added the CD player simply " floats " on top. just like an original Ginko. This EASILY bested several different cones I have in my collection, a set of Isonodes, a set of Symposium Rollerblocks, and a innertube isolation platform.

Total cost ? $15.

The bass is the tightest and most defined I have ever had in my current system. It made amazing amounts of good things happen under my Lexicon RT-20.

Try it for yourself, it was a winner in my system.
timtim

Showing 4 responses by halcro

halcro's avatar
halcro
2,664 posts
 
Bombaywalla,
Can you provide any scientific study or evidence, any physical or acoustic principles or formulae which correlates the 'knuckle rapping test' with the behaviour of 'real-world' acoustical feedback?
I see many audiophiles who place great importance on this dubious 'test' and have seen no evidence of its relevance in scientific terms?
halcro's avatar
halcro
2,664 posts
 
"I'd like somebody to explain why this is not a good test."
"I don't have any evidence at the time of writing this post so you are free to dis-regard my post re. the knuckle rapping test & carry on w/ your life.
I'm afraid that I do not have scientific evidence, etc for every tweak that I do. If I were a man who did every tweak only after I found scientific evidence I would most likely not be in this hobby."

Problem is Bombay, that you simply don't understand the physics and acoustics involved in translating 'impact-induced' sound transmission with either Structure-Bourne or Air-Bourne Sound transmission and as you say, you don't really care?
Yet you now want us to tell you why your 'rapping' test is irrelevant?
Just go ahead and enjoy yourself....but for heavens sake spare us your attempted pseudo scientific justifications?
halcro's avatar
halcro
2,664 posts
 
Impact-induced sound is exciting resonances just like structure-borne & air-borne sound with the impact-induced sound being a worst-case scenario. why are you having so much difficulty correlating the two w/o the walking stick of scientific equations???
Bombay, there are only 2 forms of acoustic feedback applicable to audio reproduction.
Air-Bourne sound transmission and Structure-Bourne sound transmission.
Please read the attached link which has diagrams to explain the two.
http://www.avguide.com/forums/sound-transmission
Unless you are inclined to sit listening whilst a friend or relative raps on your shelves and/or turntable, Impact-induced sound transmission is not a consideration in normal audio reproduction.
To validate your testing of Impact-induced sound transmission as it applies to the regular two forms of sound transmission one needs to provide conclusive and repeatable scientific tests which demonstrate a quantifiable link between the three?
To my knowledge, there does not exist any scientific evidence which establishes a direct correlation between Impact-induced sound transmission and the other two?
Without this information, all your assumptions and knuckle rapping are about as useless as your dismissal of the role of science and physics in audio?
halcro's avatar
halcro
2,664 posts
 
Bombay,
Structure-Bourne and Air-Bourne sound transmissions into materials are vastly different to those transmissions excited by Impact.
Why can't you understand this?
There is no scientific correlation between the three yet you continue to assume and state that the resonances excited by impact are just an 'exaggeration' of the other two.
As Clint Eastwood famously said.....'A man's gotta know his limitations'......and you would do well to stick to subjective comments and leave science to those who have something to contribute?
More to discover