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Author Topic: Rubber pucks?  (Read 12928 times)

johnR

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Re: Rubber pucks?
« Reply #15 on: November 19, 2008, 05:19:42 pm »

Dusk Bennett wrote on Mon, 17 November 2008 23:14


Let me play devils advocate for a second here. While I have not seen anything from Auralex to substantiate their claims on the U-Boats (that they alleviate 50-90% of LF  vibrations above 40 Hz), they do claim they have proven this via tests at Riverbank Labs. Riverbank is for real. You seem to imply, however, that these pads dont really work that well. Why? Is it because you have found through empirical study that these pads just blow or that there are too many other products that work better for the price? I'm curious.

I'm not franman, but 40Hz is not actually all that low, and a 50% decrease in SPL is only -6dB.
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andrebrito

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Re: Rubber pucks?
« Reply #16 on: November 20, 2008, 07:41:19 am »

I will also suggest CDM, that has not only elastometers but also springs and other stuff for industrial acoustics as well

http://www.cdm.be/documents/home.xml
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andrebrito

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Re: Rubber pucks?
« Reply #17 on: November 20, 2008, 12:22:11 pm »

This how leads us to another question which is one to float the floor or not... first if there's actually a need to use one and also the risks associated with using such a light upper floor creating a high MSM ressonance of the entire system.

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Thomas Jouanjean

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Re: Rubber pucks?
« Reply #18 on: November 21, 2008, 02:54:35 am »

andrebrito wrote on Thu, 20 November 2008 11:22

  [...] and also the risks associated with using such a light upper floor creating a high MSM ressonance of the entire system.


Spot on. A "light" floated floor will have vibrations and re-emission problems when a dynamic load is applied (e.g. a drummer playing) and will not decouple low enough.

IMHO, a floated floor should always be on the heavy side (concrete...), with decoupling frequency under 15Hz if possible as it starts to be really efficient at double that frequency.

Thanks for the links Andre! I can also recommend:

- Sylomer (    http://www.reinicke-gmbh.de/?gclid=CNrCzvDkhZcCFRHdlAodpydu- g )
- Merformer ( http://www.noisecontrol.nl/merfomer_online.html )
- Solutions Elastomeres ( http://www.solutions-elastomeres.com/ )

Beware that using those systems requires both acoustics and structural engineers to calculate static and dynamic loads, Loading pattern, resistance and type of concrete, resonance frequency of the floated floor etc. Not much of DIY option there...

Solutions Elastomeres are the ones providing my company with all the custom silent blocks, suspension systems and anti-drumming systems we use to decouple main speakers etc. Great stuff as they build it on plans within a 2-3 weeks window.
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Thomas Jouanjean
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avare

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Re: Rubber pucks?
« Reply #19 on: November 23, 2008, 01:26:07 am »

Thomas Jouanjean wrote on Fri, 21 November 2008 02:54

Beware that using those systems requires both acoustics and structural engineers to calculate static and dynamic loads, Loading pattern, resistance and type of concrete, resonance frequency of the floated floor etc. Not much of DIY option there...


+1.  It is not that a DIYer can not construct it, but to make do something good requires a lot of design work that is foreign to most DIYers.

Andre
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franman

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Re: Rubber pucks?
« Reply #20 on: November 23, 2008, 12:00:35 pm »

Dusk Bennett wrote on Mon, 17 November 2008 18:14

franman wrote on Fri, 02 November 2007 01:54

Fig,

Just curious about what your 're-purpose' will be...

BTW guys, we use Mason EAFM, Super W and FS/FSN for almost all of our projects. Kinetics RIM also on tighter budget slab products and roll-out for some projects. The engineering involved in properly floating a room is extensive. Loads must be accurately calculated (as per Guilfo) or it just doesn't work.... We spend a lot of time on this for every project and then we have the vendor review the designs for a double-check..

Anyway, the U-Boats are not my favorite. I just feel the rubber is way too stiff and there isn't enuf deflection. Deflection is what it's all about on resilient isolators. The resonant frequency is a directly related to the amount of deflection so if the pads don't 'give' (Compress) at least 1/4-1/2" then you aren't really isolating anything in the lower two octaves, which is what this is all supposed to be about anyway....

So, Fig.... what's your project??



franman,
I'm interested in your post. It seems you have experience with a variety of these products so you are probably able to voice your opinion.

Let me play devils advocate for a second here. While I have not seen anything from Auralex to substantiate their claims on the U-Boats (that they alleviate 50-90% of LF  vibrations above 40 Hz), they do claim they have proven this via tests at Riverbank Labs. Riverbank is for real. You seem to imply, however, that these pads dont really work that well. Why? Is it because you have found through empirical study that these pads just blow or that there are too many other products that work better for the price? I'm curious.

The U-boats are not cheap so I would expect them to make a noticeable difference.

I'd appreciate your feedback....I may have to float a floor in a studio and I want to be sure the money is well spent.

Thanks in advance!

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Chief Engineer
Recording Arts Department--
School of Film and Television
Loyola Marymount University
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www.lmu.edu




Dusk,

I have to look at the Riverbank data before I make any serious comments, but I can't tell you how many times I've seen very light sleeper style floors on U-Boats where there is absolutely NO deflection. For my ten cents, this means NO low frequency isolation.. Not really floated. That's what I'm referring to.

FM
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avare

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Re: Rubber pucks?
« Reply #21 on: November 23, 2008, 06:04:36 pm »

franman wrote on Sun, 23 November 2008 12:00


I have to look at the Riverbank data before I make any serious comments,


Fran:

Thanks for responding.  I have been waiting for your reply as the post was directed to you and it is your sandbox. Very Happy

The biggest issue with u-boats is that there is no test data, like Riverbank's, or even deflection data available to evaluate it, or to design floors with it.

Andre
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Thomas Jouanjean

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Re: Rubber pucks?
« Reply #22 on: November 24, 2008, 02:39:09 am »

avare wrote on Sun, 23 November 2008 17:04


The biggest issue with u-boats is that there is no test data, like Riverbank's, or even deflection data available to evaluate it, or to design floors with it.


Then we know the answer: no data, no cigar.
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Thomas Jouanjean
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Dusk Bennett

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Re: Rubber pucks?
« Reply #23 on: November 26, 2008, 04:03:08 pm »

Thomas Jouanjean wrote on Mon, 24 November 2008 07:39

avare wrote on Sun, 23 November 2008 17:04


The biggest issue with u-boats is that there is no test data, like Riverbank's, or even deflection data available to evaluate it, or to design floors with it.


Then we know the answer: no data, no cigar.



I actually emailed Auralex twice and did not get a real response from them. All I asked for was a copy of the test results they claimed to have. Since then I've looked into some of the other manufacturers you guys have talked about and it appears that you don't just buy a one size fits all product. It requires alot of math, time, and money which I do not have alot of in this particular case. The U-Boats looked affordable enough but without printed results they cannot seriously be considered. At that point I may as well forego the whole floated floor expense and let the joists rest on the concrete. How bad could that really be?

At the end of the day I was just trying to cut back LF emmission FROM the source room to the outside world transmitted through the floor cavity. The U boats appeared to do that without alot of work.  In this circumstance I think I'll pass on the whole thing unless someone can prove that they actually work.

----
Dusk Bennett
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School of Film and Television
Loyola Marymount University
Los Angeles CA
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andrebrito

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Re: Rubber pucks?
« Reply #24 on: November 26, 2008, 05:08:22 pm »

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Dusk Bennett

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Re: Rubber pucks?
« Reply #25 on: November 27, 2008, 12:11:45 pm »

andrebrito wrote on Wed, 26 November 2008 22:08

This is the only data I know of...

http://www.auralex.com/auralex_acoustics_faqs/faqs.asp?Q=17


That's my point. There's no scientific research included in that. Typically manufacturers who build products for the construction industry include results from 3rd party scientific studies that support their claims. The fact that Auralex does not should raise a red flag.

IMHO investing into something like that is akin to investing into the "Emporers new clothes". Cute but no substance.


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Dusk Bennett
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Dusk Bennett

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Re: Rubber pucks?
« Reply #26 on: November 27, 2008, 12:28:51 pm »

franman wrote on Fri, 02 November 2007 01:54

Fig,

Just curious about what your 're-purpose' will be...

BTW guys, we use Mason EAFM, Super W and FS/FSN for almost all of our projects. Kinetics RIM also on tighter budget slab products and roll-out for some projects. The engineering involved in properly floating a room is extensive. Loads must be accurately calculated (as per Guilfo) or it just doesn't work.... We spend a lot of time on this for every project and then we have the vendor review the designs for a double-check..

Anyway, the U-Boats are not my favorite. I just feel the rubber is way too stiff and there isn't enuf deflection. Deflection is what it's all about on resilient isolators. The resonant frequency is a directly related to the amount of deflection so if the pads don't 'give' (Compress) at least 1/4-1/2" then you aren't really isolating anything in the lower two octaves, which is what this is all supposed to be about anyway....

So, Fig.... what's your project??


Fran,

I looked closer at the RIM stuff and it lookes interesting. It is designed to be used under a slab though. Can you lay out the underlament and then build on top of the pads with 2x6's (U boat style) or does it only work by pouring a slab on top of plywood?

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Dusk Bennett
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School of Film and Television
Loyola Marymount University
Los Angeles CA
www.lmu.edu
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andrebrito

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Re: Rubber pucks?
« Reply #27 on: November 27, 2008, 06:13:32 pm »

Dusk, I agree with you 100 % !

PS -  I was in LA last year looking for a job but this VISA thing is quite complicated lol
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Dusk Bennett

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Re: Rubber pucks?
« Reply #28 on: December 02, 2008, 07:00:16 pm »

Dusk Bennett wrote on Thu, 27 November 2008 09:11

andrebrito wrote on Wed, 26 November 2008 22:08

This is the only data I know of...

http://www.auralex.com/auralex_acoustics_faqs/faqs.asp?Q=17


That's my point. There's no scientific research included in that. Typically manufacturers who build products for the construction industry include results from 3rd party scientific studies that support their claims. The fact that Auralex does not should raise a red flag.



So, I just got an email back from Auralex and thought this was worth diseminating. Not that I'm trying to pick a fight or anything but I think it says alot about a company when they don't bother to actually validate their claims with test data. If anything it really makes you appreciate those that actually take the time to do it. I've blacked out the name of the individual involved but kept the email intact


"On 12/2/08 12:56 PM, "********" <********@auralex.com> wrote:

Dusk,

Unfortunately we do not have third party testing data available on this product.  Due to the expense of testing on a product we know works very well when implemented properly, we have not had it tested.  I fully understand your hesitance in utilizing a product without test data, but I can assure you it has been used successfully time and time again.  

Best regards,

********"

So there you have it. in other words "Our product works because we say it does". Sure, I like a confident person like anyone else but you gotta love the fact that they don't believe in their product enough to test it.


There you have it. Shop wisely.
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Dusk Bennett
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Tomas Danko

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Re: Rubber pucks?
« Reply #29 on: December 03, 2008, 06:24:18 am »

Say, didn't our cool cat Mr. Ethan Whiner submit a variety of said materials from various companies for proper testing along with his own Realtraps?

Ethan?
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