alternatives to auralex foam

Posted: Sat Mar 06, 2004 10:58 pm

Hi,

The Auralex stuff is no doubt very good quality, but seems quite expensive. I want to build a drum isolation platform, and I need stiff 2 X 4 -ish strips of foam to put underneath. Any suggestions?

-Ben

Posted: Sun Mar 07, 2004 2:00 pm

Ben,

Check out www.foambymail.com for good prices on acoustic foam. That said, acoustic foam is probably not the best material for floating a drum platform. You'll likely do much better using 705 rigid fiberglass.

--Ethan

Posted: Sun Mar 07, 2004 9:53 pm

Ethan,

Why do you say that "acoustic foam is probably not the best material for floating a drum platform"? I wouldn't be surprised if it is in fact the best tested material for the money (total cost). Auralex and their customers seem to have some success with their Platfoam product for this very purpose. Rigid fiberglass is certainly cheaper, but still needs to be cut and covered with fabric to prevent shedding, and all that processing adds to the real cost. Plus there's the question of relative isolative value. Do you have any figures on this? What leads you to believe that one would do "much better" with rigid fiberglass?

I don't doubt you have a good reason for your statement. It just strikes me as counter-intuitive considering the rigidity of 705 versus the resiliency of Platfoam, and I'm eager to learn.

Lee

Posted: Sun Mar 07, 2004 11:02 pm

I was thinking that too. Wouldn't foam act FAR more as a 'shock absorber' in this kind of situation? It may not acoustically absorb as much, but mechanically I think it would fair better than fiberglass.

Posted: Mon Mar 08, 2004 12:26 am

as far as vibrations.. I think that rubber would do a better job than both rigid fiberglass and foam.. I could also be wrong.. I'm sure Eric could have some input.. I think he is the vibration expert...
I'm also confused with what the performance of 705 would be.. Ethan, can you shed some light..
thanks.
Gil

Posted: Mon Mar 08, 2004 6:46 am

Ben,

We have tested the Platfoam™ material (not the same material as our Studiofoam, btw) and it performs quite well when used as directed as a material to "float" a drum kit riser. As for how it performs versus a rigid fiberglass material, I couldn't say 100% for sure. In theory, you should be able to figure out the right amount of rigid FG material to match Platfoam's performance.

(Note to mods: Let me know if this topic needs to be moved to the Auralex forum. I thought the discussion generic enough to leave it alone, but I don't want to "rock the boat." Smile

)

Posted: Mon Mar 08, 2004 9:58 am

I am interested in this too, this is one of my 1st orders of business when the walls go up, soon.
I'll be sharing floor joists with the drummer on the opposite side of a double wall, and I need to minimize as much as possible. If 703 will work, thats all great, but somehow in that situation a rubber mat seems better.
I thought about building a 4x8 frame with a cross support, with the framing lined with that thick, wide weather stripping everywhere that it touches floor and the sheeting above it too. Wonder how that would do?

Posted: Mon Mar 08, 2004 10:09 am

Lee,

> Auralex and their customers seem to have some success with their Platfoam <

I wasn't thinking about foam meant specifically for this purpose. I thought the original poster was asking about regular acoustic foam, which as Jeff confirms is not the right stuff for floating a platform.

> It just strikes me as counter-intuitive considering the rigidity of 705 versus the resiliency of Platfoam <

Yes, 705 is "rigid," but not in the sense of a solid mass that will transmit. 705 isolates very well and for years has been a standard product for floating floors and monitor speakers.

--Ethan

Posted: Mon Mar 08, 2004 10:21 am

We're not talking 703 here, then, right?
I'll be using Knauf, 1 and inch, actually, since I found it and a decent price locally. I know 705 is more rigid, so is this the reason you are saying 705 for a riser?
Thanks,
P

Posted: Mon Mar 08, 2004 11:00 am

Dude,

Yes, 705 is twice as dense as 703 so it doesn't compress as much as 703. This is the real issue. If the material compresses it begins to couple.

--Ethan

Posted: Mon Mar 08, 2004 5:43 pm

I should have been more specific. I was referring to Auralex Platfoam.

So I am curious if others have built a isolating drum riser with rubber strips or fiberglass. Anyone have plans?

It would be nice to have something portable.

Posted: Mon Mar 08, 2004 6:48 pm

Quote:

I was referring to Auralex Platfoam.

So I am curious if others have built a isolating drum riser with rubber strips or fiberglass. Anyone have plans?

Neoprene rubber, 1/2" thick, durometer 60-80.

Posted: Tue Mar 09, 2004 1:53 am

<small>[ March 09, 2004, 06:34 AM: Message edited by: Eric Desart ]</small>

Posted: Tue Mar 09, 2004 6:40 am

Rod,

I do respect and admire you. And I know that you have the best intends.
I found what I said important AND to the point, VERY to the point. And there was NO name calling or whatever involved.

If you want to censor everything I write, I think I better leave.

My home is:
http://forum.studiotips.com/

Eric

Posted: Tue Mar 09, 2004 7:34 am

Ethan,

Your comment stating that "If the material compresses it begins to couple" is not correct.

Any product serving the purpose of a spring isolator (which is what we are discussing here) must compress in order to work.

If there is no compression it will not work - if it is fully compressed it will not work.

Thats is what makes this so difficult froma design point of view.

You have to establish the real dead and live load combinations (not the building code "safe loads") in order to determine what will work.

In addition to that - you have to take into account the long term effect of this loading on the materials involved to account for degradation of the isolator.

Picture it this way - even the springs in your car only work so many times before they need to be replaced.

It's the same with Rubber, neoprene - fiberglass - spring isolators, etc.

The action of loading and unoading live loads from these various "springs" eventally decomposes them - the amount of decomposition has to be taken into effect in order to maximise the life of the assembly.

This was the point Eric was making in his post that he has removed.

On this issue he is very correct.

Rod

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