Sexy subject title, I know!

Anybody seen this material before? I picked up some 2cm x 100cm x 200cm thick sheets the other day for a decent price. Made from recycled pieces of polyurethane of different densities - I think the density is 150 kg/m3 - the literature isn't totally clear about this, but I think there's also some 4cm thick stuff which is 80 kg/m3.

Anyway, it's bendy, but not too much, no loose fibres, nothing toxic to breathe in or irritate the skin, easy to cut. I chopped some up into big corner chunks, wrapped them all up in some old cotton curtains and totally cleaned up a 15 dB null I had in the 60 - 110 Hz region as well as 35-60 Hz (haven't finished testing).

It was just a casual experiment as I happened to come across this on a shopping expedition and it seemed too cheap to pass up. I'm glad it worked out for me, but I can't find much info on this stuff, just wondering if anybody else has any experience of using this for bass traps.

I could see how that might work. The proof is in the pudding as they say, and if your tests confirm that they work in your room then great! Have at it!

Frank

Frank

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Frank Oesterheld - GIK Acoustics
www.GIKAcoustics.com

Well, my tests are far from scientific , but I've undoubedly cleared up the deep low end nulls in my room, all the way down to 35-40 Hz, which is good news. I haven't done a thorough test yet, but I might be experiencing slightly more pronounced peaks (nothing too serious) - does this happen?

I can't find much acoustic info on this material, so this post was largely idle curiousity(!). From my inexperienced point of view the pros are - easy to handle (stanley knife), no danger of breathing in anything toxic, made from recycled material. On the negative side it is flammable and can release toxic fumes so you need to watch where you use it, definitely not in walls, near lamps etc

Quote whataboutit:

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Well, my tests are far from scientific , but I've undoubedly cleared up the deep low end nulls in my room, all the way down to 35-40 Hz, which is good news. I haven't done a thorough test yet, but I might be experiencing slightly more pronounced peaks (nothing too serious) - does this happen?

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I'd be surprised if it's working that low...testing would prove it though. What you may be hearing are shorter ringing times up higher, which makes the lower lows more pronounced. That's also the reason for the other issue you bring up: treatment doesn't typically *cause* other peaks, but it does *reveal* the issues that were formerly covered up by low end mud.

Frank

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Frank Oesterheld - GIK Acoustics
www.GIKAcoustics.com

I'll definitely do some thorough testing when I get a chance. I was using test tones and a sound level reader, but only had time to quickly check on a few frequency bands. What I noticed right away was all those low end areas were cleaned up, as well as slightly higher peaks.

Obviously, I'll have to take the time to do it right, I'm sure the 35-50 Hz zone isn't totally level, but it was almost non-existent before. As for the peaks, I'm only using a Radio Shack meter so maybe those slight increases are down to suspect measuring... I mentioned it in case this was a recognised phenomenon as I know so little about the subject.

As for the tests, I need to do some analysis because I placed a panel on the back wall on top of my record shelves, it's practically touching the ceiling but I'm not sure it's doing very much.

ps Thanks for the interesting feedback Frank!

Quote whataboutit:

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As for the peaks, I'm only using a Radio Shack meter so maybe those slight increases are down to suspect measuring... I mentioned it in case this was a recognised phenomenon as I know so little about the subject.

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You can get calibration files for the different Radio Shack models, the older analogue models are more accurate in the low end than the digital ones and are considered quite accurate up to 3000hz.

A common free program to use for testing is Room EQ Wizard, you can calibrate your soundcard and also load the relevant calibration file for your meter.

I would be interested in any results (graphs/waterfall plots) you could post.

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Visit Hypagen on Myspace

Have you got a link for this for sale anywhere? Sounds interesting.

To be clear - I did my original testing and calibrating using realtraps's test tones CD and plotted the graph by hand, so I'll need to repeat the same process to get a meaningful comparison. The Radio Shack meter does seem very decent for my purposes (new digital model) but I imagine that I can't rely on it for totally strict results so I could explain away an increase of a few dBs what with slightly different listening position, waning moon etc

Neverthless I'll post the before and after graphs as soon as I get some time to run the tests. Mixing these last couple of days has been quite pleasurable compared to before when I had those unnerving nulls.

ps I'm using the above testing method in part due to the fact that I can't get Room Eq Wizard to work on my computer, I think it's because it has never been connected to the net and doesn't have the necessary Java updates...

I can't find anything apart from this link (it's in Spanish, sorry)- http://www.isolplus.es/catalogue.php?cat=9

I bought the stuff at Leroy Merlin (DIY supplies store), apparently some people use it for soundproofing. I can't find anything at all about using it for bass traps, but that's probably because rockwool does the job (I was having trouble getting my hands on higher density rockwool).

Google translation: Acústic Copopren New formula

This product makes me think of the Vicoustic Isolation Line blanket product.
Seemingly not having the same potential use against low freq issues as the Spanish product, these blankets may be interesting for other applications, and are at least fire approved in Portugal, and hence I guess wouldn't be too problematic to get approved at least in other EU countries (don't know if this has already happened..)

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/van

Edited by van Sinn (02/09/09 09:55 AM)

hm. going to check my local leroy merlin in france, see if they do it too.

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Me? But I`m such a loveable old bugger!