flexCL Acoustic Data

[sound_music]

i've been searching through the forums here and at john sayers, and on google, and even on homatherm's own site (makers of the flexCL product), and cannot find any actual data sheets to support their sound absorption claims.

from what i can tell all these claims have been extrapolated from the product's density and gas flow resistance numbers. but have the product's sound absorption properties actually been scientifically tested in a lab? (and btw, i've been unable to find the GFR numbers myself, but apparently they're out there somewhere--just not on homatherms site. it has been posted in another GS thread that they have a GFR of 43000 to 76000 rayls/m. how can the varience be so wide!? doesn't make sense to me, would love an explanation if someone's got one...)

if someone can put up a link to such data it would be greatly appreciated. i've been looking for recycled material like this for some upcoming absorption panels/traps, and would love to buy the product if the claims can be substantiated!

[MrCrowbar]

Originally Posted by sound_music

i've been searching through the forums here and at john sayers, and on google, and even on homatherm's own site (makers of the flexCL product), and cannot find any actual data sheets to support their sound absorption claims.

from what i can tell all these claims have been extrapolated from the product's density and gas flow resistance numbers. but have the product's sound absorption properties actually been scientifically tested in a lab? (and btw, i've been unable to find the GFR numbers myself, but apparently they're out there somewhere--just not on homatherms site. it has been posted in another GS thread that they have a GFR of 43000 to 76000 rayls/m. how can the varience be so wide!? doesn't make to me, would love an explanation if someone's got one...)

if someone can put up a link to such data it would be greatly appreciated. i've been looking for recycled material like this for some upcoming absorption panels/traps, and would love to buy the product if the claims can be substantiated!

I've seen on some german forum that FlexCL has big variances, but I couldn't figure out why and what the data was based on. I'm in the same boat as you, looking for a bass trap material that doesn't emit nasty gases and fibers. I figure if you stack thin layers into a thick one, you can effectively minimize that variance because stacking random GFRs on top of each other is the same as having the average GFR.

That said, I don't think that variance is that relevant for bass trap building. If you have found a similar but cheaper material, let me know. FlexCL seems to be rather expensive.

[jeremyglover]

i bought a bunch of it and put it up in my room and now it sounds much better.

it's a good, cheap and healthy alternative to other acoustic products ..

this does nothing to answer you question so i will leave now ..



jeremy

[MrCrowbar]

Originally Posted by passivepeter

i bought a bunch of it and put it up in my room and now it sounds much better.

it's a good, cheap and healthy alternative to other acoustic products ..

this does nothing to answer you question so i will leave now ..



jeremy

Where did you buy it?

[sound_music]

thanks for your opinions guys, anyone's experiences with / impressions of the flexCL stuff is also helpful and welcome, but really i'm trying to find some hard data to support the company's acoustic claims.

anyone...?

[Northward]

Originally Posted by sound_music

thanks for your opinions guys, anyone's experiences with / impressions of the flexCL stuff is also helpful and welcome, but really i'm trying to find some hard data to support the company's acoustic claims.

anyone...?

You will find the data you're looking for on their german website. It's all there, lab measurements etc for 40mm thick Flex CL.

We have measurements for 100mm Flex CL, but they are not public because privately funded.

The product is amazing.

[MrCrowbar]

Originally Posted by Northward

You will find the data you're looking for on their german website. It's all there, lab measurements etc for 40mm thick Flex CL.

We have measurements for 100mm Flex CL, but they are not public because privately funded.

The product is amazing.

Sounds good to me. Guess I'll try it out sometime, putting a monitor on the floor, speaker upward, and moving a FlexCl mat around while playing sine waves at increasing frequencies. If I don't hear any difference when moving the mat around, it's good enough.

[jeremyglover]

Originally Posted by MrCrowbar

Where did you buy it?

38 SCHESLIESERSTRASSE BERLIn, near gorlitzer bahnhof .. walk into the court yard and it's on your right. i forget the name of the place.
they have always had it in stock when i needed it.

you can also check this thread:

my insprirations for DIY basstrap builders

[MrCrowbar]

Originally Posted by passivepeter

38 SCHESLIESERSTRASSE BERLIn, near gorlitzer bahnhof .. walk into the court yard and it's on your right. i forget the name of the place.
they have always had it in stock when i needed it.

you can also check this thread:

my insprirations for DIY basstrap builders

Anything in Munich maybe? Or do they deliver to your home?

[jeremyglover]

i went to a store in berlin,
i hope to get there again next week.
i'll ask about munich ..

[MrCrowbar]

Originally Posted by passivepeter

i went to a store in berlin,
i hope to get there again next week.
i'll ask about munich ..

Thanks. I'm so glad I finally found a material that would work for me. Wouldn't mid driving to Berlin, but you kinda need a big van to get it all back home.

[mikahanau]

You can ask hometherm for a dealer in your area.
here you find the contact site:
Informationsanfrage *|* HOMATHERM

most of the time the give you a call very soon.
cheers
mika

[MrCrowbar]

Originally Posted by mikahanau

You can ask hometherm for a dealer in your area.
here you find the contact site:
Informationsanfrage *|* HOMATHERM

most of the time the give you a call very soon.
cheers
mika

Awesome. Thanks!

[jeremyglover]

BTW they come in 2 different sizes that i've seen one is 4cm thick the other closer to 7cm ..

[DanDan]

There is a common assumption, perhaps even intuitive, that these dirty chemical sourced panels are toxic, smelly, even carcinogenic. On the other hand the animal and plant products are warm and safe.
Actual studies have shown the opposite is often the case.
RockWool dissolves in the body within weeks, Cotton can take 18 months.

The Comparative Safety of Rockwool, Fiberglass, and Organic Fibers (a review)

So be careful with Cotton and Cellulose dust. And be aware that some of the bad guys come up as good guys in the tests, e.g. Roxul.
I suspect Ecose would do well also.

DD

[tun]

Originally Posted by Northward

You will find the data you're looking for on their german website. It's all there, lab measurements etc for 40mm thick Flex CL.

We have measurements for 100mm Flex CL, but they are not public because privately funded.

The product is amazing.

Guys, inspired by the Amsterdam studio build and Northward's comments, I'm considering FlexCL to treat my back wall in the manner recommended by him. However, I can only get the 30mm thickness here, and the dealer says it's more like 25mm thick than 30mm.

So, I'm considering 6 traps, each containing 7 panels of FlexCL to give me a thickness of just under 18cm. There'll be an air gap of around 18cm between the absorbent material and the wall. 6 traps will just about do my entire back wall.

My questions are as follows:

Will multiple layers of a thin panel (7 x 25mm) give the same amount of absorption as using 1 x 18cm thick panel? Are the FlexCL flow resistivity figures uniform throughout the product range and various thicknesses?

Also, I'm looking to absorb as deep as possible into the bass freq's, but is layering 7 x 25mm panels excessive? Could I get away with 6 layers or even 5 layers? Or would that mean less low freq absorption? I've read Northwards comments that 12cm to 15cm would be sufficient for 1st reflection points, but also noted that the Amsterdam build utilises 18cm thickness for the back wall, so that's why I'm planning to use 7 x 25mm panels.

Finally, the price over here for 42 x 25mm FlexCL panels (including vat and delivery) will be the equivalent of €263 / US$379 / £229. That's a lot of money. Is FlexCL really that good as Northward suggests? Should I go for it? Or should I look for an equally suitable but cheaper solution?

All input greatly appreciated!

Cheers

[audiomuze]

Originally Posted by sound_music

i've been searching through the forums here and at john sayers, and on google, and even on homatherm's own site (makers of the flexCL product), and cannot find any actual data sheets to support their sound absorption claims.

Here's a link to some data on their website. It's in German though.

Determination of sound absorption by DIN EN 20354 in the echo chamber