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R/E/P => R/E/P Archives => Acoustics in Motion => Topic started by: Fig on October 26, 2007, 06:07:32 pm

Title: Rubber pucks?
Post by: Fig on October 26, 2007, 06:07:32 pm
Hi all,

I remember reading about some rubber "pucks" used to isolate studio floors from a concrete slab in the hopes of alleviating mechanical vibrations from passing traffic and other seismic events.

Does any one know the supplier of such things?

Any assistance is greatly appreciated.

Thanks and regards,

Thom Fiegle
Title: Re: Rubber pucks?
Post by: gullfo on October 26, 2007, 09:53:53 pm
Mason Industries - heavy duty floor isolation and wall mounts
http://www.mason-industries.com/masonind/private/overview/pr oduct_overview.cfm

PAC International - RSIC supplies for framing and drywall.
http://www.pac-intl.com/products.html

consider that the floor mass should to be designed to have a resonant frequency about 1/3 of the expected lowest frequency you are encountering (or generate if outbound isolation is important). this is to ensure the level of the lowest frequency will be reduced enough to meet your noise criteria.

often this means floating concrete, or second best, using framed floors with the addition of mass building materials (sand, cement board, steel plates, lead, etc).

Hopefully someone can jump in to add more/better ideas.
Title: Re: Rubber pucks?
Post by: jfrigo on October 27, 2007, 02:39:13 am
Some other places to look for floor solutions:

http://www.kineticsnoise.com/arch/floors.aspx

http://www.auralex.com/sound_isolation_uboat/sound_isolation _uboat.asp

Re: vibration isolation, it can get pretty complex. You can do some simple floor isolation and get a bit of help, but to get it done right, it takes more than putting something soft under your floor.

You need to take into account the forcing frequency (the lowest frequency you're trying to isolate against) and the natural frequency of the isolator (periodic sinusoidal oscillations, i.e you remove a load from a spring and it bounces up and down). You need to calculate the required static deflection, and have a proper isolator for your load and the required deflection (typically spring or neoprene, but there's quite a range of possibilities within the two types).

Load dispersion and center of gravity (where you get displacement without rotation) are also to be considered. There is, of course, plenty of math available to help you figure these things out, but you need accurate information about your conditions to be able to plug useful figures in. The wrong isolator can actually amplify certain vibrations and increase transmissibility rather than diminish it.
Title: Re: Rubber pucks?
Post by: crna59 on October 28, 2007, 01:21:16 am
These are Auralex U-boats.

Regards,
Bruceindex.php/fa/6559/0/
Title: Re: Rubber pucks?
Post by: crna59 on October 28, 2007, 01:22:40 am
Close up view.

Regards,
Bruceindex.php/fa/6560/0/
Title: Re: Rubber pucks?
Post by: Fig on October 29, 2007, 01:07:42 pm
Thanks all,

I'm repurposing the products - so all the technical tips, while appreciated, are not necessary.

I think the Auralex U-boats are gonna work best.

Thanks again.

Fig
Title: Re: Rubber pucks?
Post by: franman on November 01, 2007, 09:54:37 pm
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??
Title: Re: Rubber pucks?
Post by: Fig on November 02, 2007, 12:00:52 pm
franman wrote on Thu, 01 November 2007 20:54

Fig,

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

<snip>

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



Hi Fran,

Can you provide a link to the products you suggest?

I have a client that claims to be experiencing (hearing/feeling) seismic vibrations in the infrasonic range.  He is a music student in an apartment building and suspects an HVAC system that is located about a block away.  His neighbors do not experience it, but they may not be as sensitive as he is, or perhaps - due to geometries and whatever, not receiving these "sounds" in their apartments at all.

As an experiment, I've suggested that he isolate his bed or sofa from his floor and then sit on it without being in contact with his floor or walls in any way.  If this mechanical isolation has any effect, we will proceed from there in trying to somehow isolate his furniture, wall hangings, etc. from the structure in which he is living.

Does anyone remember the situation in Kokomo Indiana where people were "hearing" a seismic event from miles away in a quarry?  My brother lives out there and told me about the phenomenon.  I've been unable to find out how it was resolved, but residents took it to court as noise pollution or some such claim.

If anyone has any suggestions beyond my crazy idea above, please forward them to me.

Osci-later,

Fig

Title: Re: Rubber pucks?
Post by: gullfo on November 02, 2007, 04:44:31 pm
maybe its possible to get some actual measurements using sound level meters and something like room eq wizard or ETF to determine what noise/sound/frequency levels are in the space. this way suggestions on treatments will be more likely to be successful... contact mics can be used to try to determine the entry points of any significant noises.
Title: Re: Rubber pucks?
Post by: avare on November 02, 2007, 05:26:56 pm
Wht a new ballgame!  You don't know the frequencies involved?  Floor isolation is expensive at low frequencies.  The lower the frequency, the greater the expense.  

Get some contact mics and/or accelerometers and determine the frequencies.  After that determine the source.  It may be cheaper to have some work there.  I recall reading about a studio with traffic noise problems.  The final, only effective, and effective solution was a saw cut in the concrete coupling the building to the roadway.

Quietly:
Andre
Title: Re: Rubber pucks?
Post by: gullfo on November 03, 2007, 07:53:03 am
Fig wrote on Fri, 02 November 2007 12:00

Can you provide a link to the products you suggest?


check back a few posts - Mason, PAC, and Kinetics links are there. which ones to use depend on the design criteria which will be based on the desired characteristics of the floor, the environment its going into, and the budget...
Title: Re: Rubber pucks?
Post by: meverylame on November 03, 2007, 09:38:44 am
Honestly I've seen someone use hockey pucks to a great degree of success.
Title: Re: Rubber pucks?
Post by: franman on November 03, 2007, 04:43:36 pm
Fig,

As mentioned by Glenn, the links are above... With regards to testing, siesmic activity requires an accelerometer and appropriately calibrated vibration test equipment.. We have been wanting to experiment with an accelerometer attached to the TEF (via a pre-amp) but it would be hard to put 'absolute' values to the measurements. The TEF output signal is a reference and therefore, once you calibrate your microphone sensitivity you always have absolute values...

Hockey pucks.. I don't think so... The rubber has almost no elastomeric qualities. (it doesn't compress)...

As I mentioned above, the LF cutoff or resonant frequency in any structural isolation system (except springs) is directly related to the amount of deflection (compression) in the isolation system. The hardness, durometer and compression all factor into determining the resonant frequency and efficiency at the lowest frequencies approaching the resonant frequency. We do not use Sorbothane for room isolation, but they have a cool little calculator for determining the size of a pad under a specified weight... see:

http://www.sorbothane.com/   see the download design guide... You may be able to try the sorbothane for the 'bed isolation' project. We use this product for isolating main in-wall speakers from the wall systems. It's excellent for that!!

This subject of low frequency structural isolation is so often misunderstood in our business. It almost could take an entire forum of it's own.... I was lucky early on in my career to collaborate with some very knowledgable and helpful consultants and they steered me in the right direction as far as structural isolation. I see so many 'wrong' things done in this area, even by some well respected designers... of course, what do I know? I'm just an old pony-tailed studio rat!!
Title: Re: Rubber pucks?
Post by: Fig on November 04, 2007, 11:03:08 am
franman wrote on Sat, 03 November 2007 15:43

... of course, what do I know? I'm just an old pony-tailed studio rat!!


Thanks again, Fran and everyone.

I'll be the first to admit that I am out of my league here - being a fader jockey.  Just trying to get a fellow some sound sleep in the presence of a low hum that permeates his living quarters.  Poor guy.

I'm gonna send him a link to this thread so he can decide for himself if he should persue this or find a new place to rent (possibly easier and probably cheaper).

Osci-later,

Thom "Fig" Fiegle
Title: Re: Rubber pucks?
Post by: Dusk Bennett on November 17, 2008, 06:14:38 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??



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!

----
Dusk Bennett
Chief Engineer
Recording Arts Department--
School of Film and Television
Loyola Marymount University
Los Angeles CA
www.lmu.edu

Title: Re: Rubber pucks?
Post by: johnR 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.
Title: Re: Rubber pucks?
Post by: andrebrito 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
Title: Re: Rubber pucks?
Post by: andrebrito 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.

Title: Re: Rubber pucks?
Post by: Thomas Jouanjean 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.
Title: Re: Rubber pucks?
Post by: avare 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
Title: Re: Rubber pucks?
Post by: franman 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!

----
Dusk Bennett
Chief Engineer
Recording Arts Department--
School of Film and Television
Loyola Marymount University
Los Angeles CA
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
Title: Re: Rubber pucks?
Post by: avare 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
Title: Re: Rubber pucks?
Post by: Thomas Jouanjean 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.
Title: Re: Rubber pucks?
Post by: Dusk Bennett 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
Chief Engineer
Recording Arts Department--
School of Film and Television
Loyola Marymount University
Los Angeles CA
www.lmu.edu
Title: Re: Rubber pucks?
Post by: andrebrito on November 26, 2008, 05:08:22 pm
This is the only data I know of...

http://www.auralex.com/auralex_acoustics_faqs/faqs.asp?Q=17
Title: Re: Rubber pucks?
Post by: Dusk Bennett 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.


----
Dusk Bennett
Chief Engineer
Recording Arts Department--
School of Film and Television
Loyola Marymount University
Los Angeles CA
www.lmu.edu
Title: Re: Rubber pucks?
Post by: Dusk Bennett 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?

----
Dusk Bennett
Chief Engineer
Recording Arts Department--
School of Film and Television
Loyola Marymount University
Los Angeles CA
www.lmu.edu
Title: Re: Rubber pucks?
Post by: andrebrito 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
Title: Re: Rubber pucks?
Post by: Dusk Bennett 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.
Title: Re: Rubber pucks?
Post by: Tomas Danko 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?