Racquetball isolation platform perfection

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

I never dismissed science & physics in audio! you have misconstrued my words & minced them to mean whatever you thought. In earlier posts in this thread I was talking about the physics of rotational machines with Chashas1. Did you gloss over those posts?? Obviously I know better than to simply dismiss science & physics in audio. What I said was that I did not believe that there was a need for scientific formulae for this particular test. Read my post(s) again.
Thanx for the link - I'll read it.

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

I agree with you that it's not considered normal to have a friend knock on your rack while listening. Let me re-iterate (for the nth time) my objective of my test - I want to see if the rack/shelf/plinth resonance is excited will I be able to hear it. I really do not care how the resonance is excited just that once it's excited I want to kill it off. Also, material's resonance is only 1 freq no matter how it is excited - knocking, air-borne, structure-borne. So, I knock on the various components & check if there is an adverse sonic effect of this. If there is, I trace it & work on dissipating the resonance. Once I'm satisfied, then, I can be reasonably sure that if resonances are excited via air-borne or structure borne transmissions (as cited in the link you provided), I will not hear them.
You can do this test by actually inducing air-borne &/or structure-borne sound xmission; it's easier, more expedient & gives the same results (afterall the objective is to try to excite resonances) if one knocks on various materials & sees if they need work damping-wise &/or isolation-wise.

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?

Structure-Bourne and Air-Bourne sound transmissions into materials are vastly different to those transmissions excited by Impact

WTF cares if they are different mechanizms of sound transmission. The net effect on the gear, rack, TT is the same - resonances in the gear, rack, TT are excited.
Why can't YOU understand that I'm NOT concerned with how the resonances are excited. I'm merely concerned with exciting resonances & dealing with dissipating them.
When I want to differentiate amongst the different mechanizms of sound propagation I'll ask you. Right now I'm concerned with exciting resonances & dealing with them appropriately. Understand???

[quote]There is no scientific correlation between the three[/quote]
you have said this a few times now. Where have you read this? Do you have any evidence of this? Or, is this your conjecture??

and you would do well to stick to subjective comments and leave science to those who have something to contribute

You would do equally well by NOT counting yourself amongst those who have any scientific knowledge to contribute. I read the posts thru the link you provided earlier. The manner in which you have dealt with the subject is total a joke! It's totally risible - it's half-assed, hand-waving & you hide behind

but there are many more issues involved and it is infinitely more complex than my basic description

!

Halcroman, the great science contributor using language the following language in his treatise of structure-borne, air-borne sound transmission:

Also the frequencies that are happily carried by one material may be UNHAPPY in another material

happy frequencies & unhappy frequencies.... soooo scientific, Halcroman!

This is why turntable manufacturers laminate dissimilar materials to form their platters so that various frequencies are prevented from ‘jumping over’.

yes, more scientific verbage - frequencies are jumping over.......just like the cow jumped over the moon!

With this knowledge, it is easy to see that the long-wavelength frequencies in the wall are not HAPPY to travel in the thin metal brackets which are attached to it

more talk about unhappy frequencies....
Boy, by this time in your treatise on the subject, I'm feeling like I'm being taught by an authority on the subject.

the shelf being DENSER than the bracket, will scoff at the minute high-frequencies it sees

Oh boy, the shelf is now getting an attitude! It's scoffing at some unhappy frequency that wants to come into the shelf. Very scientific, Halcroman!

Of course if you really want ULTIMATE decoupling, placing some rubber or neoprene between the bracket and wall is even better

Alright! Now we have come to *the* ULTIMATE solution. This is it, guys, look no further - if you want to decouple to the best ability that mankind knows none other than *the* Halcroman has written it (pretty much like the statement we read sometime back that Al Gore invented the Internet).

However the physics and acoustics are undeniably on the side of mounting the turntable off the wall and NOT on a floor mounted stand

The final line in the treatise on the subject - according to Halcro it is UNDENIABLE at this point that a TT should be mounted on the wall. The crap that you have written in the lines before the final statement is a whole bunch of hand-waving, obvious statements that anyone can find in a textbook covering acoustics such as F. Alton Everest & many others. There is no logical progression thru the obvious statements you have written & you conclude UNDENIABLY that TTs should be wall-mounted. You MUST have terribly flunked logic in the GRE (if you even went to grad school).
Halcro, you are a joke when try to toot your trumpet & try to call yourself a man of science. Just hide your face & crawl back in your shell.

Bomby, you have a great chance to learn here, but you are too busy arguing with everyone, i think you will soon start arguing even with yourself. You've had several good knowledgable people give you advice, and you cannot stop to see it. Stop chasing your tail.
I kept checking the thread because I thought you were so funny, now I leave it because I am sad for you.

Chashas1,
Please don't be sad for me & please don't pity me - I know when I've shut my mind to new knowledge, when I've opened my mind, when I'm upset at somebody & when I'm agreeable with somebody.
I don't like tooting my own horn & I don't like patting myself on the back. I bring this here only because I believe that it's needed now - Look at my 100s of posts since I joined A'gon & see how many times you can find when I actually got into a fight w/ somebody. You'll find that you can count these instances on 1 hand & you'll also see that it wasn't me who started the fight - it was provoked by the other party.
I'll say this about myself - I'm a pretty agreeable chap & DISLIKE VERY MUCH getting into a fight. I've got an open mind & have NO PROBLEM even a newbie teach me. I DO NOT KNOW everything there is to know about audio. I've never claimed it nor will I.
However, both you, Chashas1 & Halcro have come into this thread with great belligerence & with a great air of superiority & with harsh words for me esp. Halcro. His words have been demeaning & condescending. He has always written his posts in an off-hand dismissing manner. And I take serious offence to this method of treating another A'gon member who happens to be in good standing. There are many other ways to make your point without rubbing the other person the wrong way. Neither of you had the humility to do so. Obviously, you got the fight you were looking for.

While I understand that there are sound transmissions via air-borne & structure-borne, I also realize that these transmissions are doing mainly 1 thing when they come in contact with the rack, shelf, TT plint, TT platter, etc & that is excite resonances.
If the objective is to excite resonances - and, this IS my intention - then there is more than 1 way to do so. I'm sure that you will agree with me on this (there is usually more than 1 way to "skin the cat" as the proverb goes). Thus, knocking on the above mentioned components is 1 method to excite these resonances. These resonances are impact-induced, agreed. The resonances in real-life might not be impact-induced, also agree. However, if you cut thru the chase, what is air-borne & structure-borne sound transmissions doing to the audio gear?? It is principally exciting resonances in those materials.
What is impact-induced sound xmission doing? Also exciting the same resonances!
You will agree with me that a material's resonance frequency is only 1 particular frequency whether it is excited air-borne or structure-borne or impact-induced. Thus, the simple, easy method of using impact-induced sound xmission to debug where one is lacking adequate should be just fine to resolve the issue.
Then, in real-life when these resonances are excited in whichever way that Halcro & you deem correct, the listener can be quite sure that the effects will be minimized.
I believe that both Halcro & you have failed to see this. Both of you have been stuck with the notion that since sound transmissions are only 2 types, one simply cannot debug the issue any other way! You KNOW that's simply NOT correct. The other thing is at this point where I am testing isolation, I believe that I am not concerned with HOW sound transmits to the rack, shelf, plint, platter; what I am concerned with is that somehow the resonances are excited. Both Halcro & you have failed to realize this & keep going on & on about air-borne & structure-borne.
I will NOT believe for a minute that the resonance frequency for air-borne & structure-borne sound xmissions is a different frequency from that for impact-induced. I believe that it just cannot be - once a material resonants it resonants at it's 1 resonance frequency. Thus, for the purposes of debugging the isolation issue, it does not matter how the resonant freq got excited; merely that it got excited.

Both you & Halcro have been pretty demeaning in your posts in this thread & have provided zero knowledge & suggestions on how to actually debug the isolation issues. Atleast Undertow had a much better attitude - he suggested an experiment, shared a story about his friend, trolled the A'gon website & provided links to people's systems as examples for us to look at. Both you & Halcro did nothing of this sort, except waltz into this thread with a great deal of arrogance & an air of superiority. Anybody would take offence to that!

Above is my last attempt to explain where I was coming from. It's very likely that it will still not sink in with you. If that's the case, so be it. I know that I tried. Good day to you, Chashas1 & Halcro.