have I found it? the green alternative to fiberglass- 3M Thinsulate

[Coconutout]

Hi guys, I just wanted to share with you my finds.
I had been looking for that magic acoustic material for my statement transmission tunnels for a while. I stopped using fiberglass since learning that it's a source of formaldehyde emission. Eggcrate foams barely seemed to get the job done in the tunnel. The tunnel resonance was clearly heard at the recommended thickness. (my enclosure material is BB so your experience may vary with mdf) Next I tried sonic barrier and that did the job too well- the midrange now lost all 'air' and dynamic. The stuff had literally put a barrier on the airflow. And this was at mere 1" thickness. So as a last resort I loosely stuffed the empty tunnels with polyfil. The sound was acceptable but still I sought better.
Today I got to try stuff called Thinsulate. It's made by 3m for arctic insulation. the crosscut of the stuff looks like polyfil made into a cotton candy and flattened. It's very light density and air permeable (is that the right term?) yet expensively woven. The moment I turned on the music, I knew my searching was over. Wow wow. No tunnel resonance at all yet the air and dynamic is as good as a dampener free tunnel. The sound is totally open. There's so much ambiance now and it's all crystal clean. Thank you 3M!

P.S. another little mod i tried out today and keeping is- removing the rubber boot on the RS-180. I just did it out of curiosity and it actually improves the sound. upper bass is more defined now and so far I haven't detected any distortion, so now I'm thinking maybe the boots are put on there for looks and/or car audio application? anyways, I urge to you give it a try if you have Statement monitors. go ahead, take off those boots!

[AdelaaR]

Here in Europe the name "thinsulate" is widely used for all kinds of winter clothing using the 3M insulation but I've never heard of thinsulate being available for purchase seperately.
Did you buy this in a normal shop and if so what is the exact name of the product?

[ThomasW]

I stopped using fiberglass since learning that it's a source of formaldehyde emission.

There is fiberglass available that doesn't contain formaldehyde. Most of it is white in color instead of the familiar yellow or pink.

Did you buy this in a normal shop and if so what is the exact name of the product?

Title of the thread "3M Thinsulate" is the name of the product.

It's sold in the US by retail stores offering fabrics by the yard

'Bonded' polyester is a similar option and is also sold by fabric stores

[Hdale85]

All the big hardware stores actually don't sell the fiberglass with formaldehyde anymore. We just bought a bunch of insulation for a room recently and I was surprised to see it's no longer pink.

[Curt C]

The tunnel resonance was clearly heard at the recommended thickness. (my enclosure material is BB so your experience may vary with mdf)

if you have Statement monitors. go ahead, take off those boots!

I'm glad you found a solution to the resonance issues in your build. This is the best example I've seen of the difference in damping between MDF and BB. Since it is 'open back', one would think the enclosure walls would 'see' far less acoustic energy than a typical sealed midrange enclosure, but obviously there was enough to excite the panels. The tunnels on the Mini's are well braced as well, so bracing alone doesn't appear to resolve the issue, at least in this instance.

It's too cold here to take off my boots!

C

[Coconutout]

^ hehe, thank you, Curt. It's been a long journey. In the end, I don't find BB to be an ideal material but the formaldehyde issue with mdf was something I couldn't ignore. Even with the woofers, I still get a slight coloration that I need not complain about- because it's that warm woodiness that I like to call 'musical'. It could be because I didn't choose the best quality BB, (9ply) but if not, then I think BB is better suited for bigger enclosures where there's more flexibilities for extensive bracing. Of course that's only my speculation. :B

'Bonded' polyester is a similar option and is also sold by fabric stores

I did try the bonded polyester but since it was really so ineffective as to be insignificant, I didn't bother to mention. In fact, it wasn't even as good as the egg crate foam. It's dense and doesn't damp well at all at all frequencies. The thinsulate, however, is in an entirely different league. I should add (for a little brag) that the sheet I tried is in mere 15mm thickness- about 3/4 of an inch. I'll be ordering the inch thickness sheet and expect improvements.

I'm glad to learn that about the white fiberglass stuffings. another issue that bothered me though, was the dust. Not only was the dust generated while working with the stuff almost unavoidable, (especially since I live in an apartment with no access to a workshop) but I also worried about the dust that could constantly generate as the air flows in and out of the port. That issue however, was still debatable last time I checked.





P.S.S. I also replaced the speaker cables for the tweeters with jeweler's silver wire, 1mm. this has also been a major improvement and it must be as good as any 99.9% silver cables from a named brand because I get all the said benefits- more natural sybillance, smoother presentation, that crazy imaging... and it only costed me $10 per meter. I plan on doing the same for the tangbands. and no it doesn't sound any brighter nor bright at all by any standards. that taboo only applies to silver coated copper, I believe.

So far with these cheap tweaks, my monitors have jumped another league in fidelity. I highly recommend these materials. You won't regret them. I'm hearing things I've never heard before with my original statements in the same music. And the statements were driven by good quality seperates. The monitors right now are hooked up to a mere onkyo theater receiver. My Unico P couldn't get here sooner oh and praise Jim, Curt and the people who made this design possible.

[chrismercurio]

I believe Bonded Logic is the "green" alternative to fiberglass. It makes dust, but no itching...

http://www.bondedlogic.com/ultratouch-cotton.htm

[Coconutout]

^hey that's a cool find. Always happy to see a new green product. the denim stuff seem too dense to be put in enclosures, though. I would still love to have my future home done with the stuff.

[chrismercurio]

I have used it in enclosures just fine as have many others. Since it is a building material it's quite affordable as well.

[ThomasW]

In the end, I don't find BB to be an ideal material but the formaldehyde issue with mdf was something I couldn't ignore.

Home Depot where I live sells formaldehyde free MDF.

[Face]

Home Depot where I live sells formaldehyde free MDF.

You're lucky.

[Coconutout]

Hi. I've done another mod to my statements that I think is recommendable- acoustically suspending the tangbands Instead of fixing them to the baffle with screws, I 'levitated' them with sticky silicone earplugs. I rolled the earplugs into an even string and used that in place of weather strips, first tightly pressing the woofer with screws to help the silicone achieve a firm 'stick'. then when I removed the screws, voila, they're staying stuck and is air sealed. This effectively reduced the vibration transfer from the baffle to the tangbands. When I put my ear to the enclosure and tap on the driver baskets, the tangbands now make a different sound from the daytons and founteks. It is more of a muffled thud than a sharp twang of the other two. and the sound has become noticeably more clean. Instrument separation is better, and it's more transparent sounding. give it a shot if you're bored.

[DAVE.S]

i am thinking about the silver wire mod. Have you done a double blind test to see if it is not just the placebo effect and see if you really can hear a diffrence? next time just change one speakers cable and not the other then do a double blindtest if you like the altered speakers better 10-10 times then ill do it in a heartbeat

[Coconutout]

well the difference between the sound of silver & copper is known to be pretty dramatic so I doubt it was any placebo effect that I heard. If you're worried about the time you might waste putting your statements through a surgery, you might want to give silver interconnects a try. If you notice the difference and like it, I'm sure the next step won't go to waste either.

[cjd]

well the difference between the sound of silver & copper is known to be pretty dramatic so I doubt it was any placebo effect that I heard.

Known to be pretty dramatic?

Last time I heard people acclaim a wire, they couldn't even identify what changed.

While there CAN be differences, I'd venture to suggest they are anything but dramatic. They are subtle.

[DAVE.S]

anybody who uses the word dramatic when it comes to cable loses some credibity with me

[Coconutout]

What some feel as subtle might be dramatic to others. It's a subjective term. No word in the english language is forbidden when describing one's experience in this hobby.

And Dave, asking me to perform 10 blind tests when it's your ears that are skeptical, and discrediting me even before doing them yourself? ridiculous. I doubt your credibility would be worth my effort.

[DAVE.S]

oh well silvers cheap enought that ill try it ill update when i can

[gbegland]

^hey that's a cool find. Always happy to see a new green product. the denim stuff seem too dense to be put in enclosures, though. I would still love to have my future home done with the stuff.

No, not at all. Just the opposite, it actually DOES something down into the lower mids quite nicely. Best box stuffing out there. Been using it for over 2 years now and not looking back. Great for DIY acoustic panels too.

Greg

[DancesWithBeers]

You can also try putting magnets in the corners of your room to prevent stray currents from reaching your drivers. This really opened up the sound for me.

[Coconutout]

I also heard that praying in front of your speakers soothes the distortion devils but I won't go that far. ;P

I'd love to try the bonded logic stuff, but I'm currently in china and can only rely on materials that can be bought on taobao.com

[Hank]

Thank you 3M!

You're quite welcome, Coconutout! History: we invented Thinsulate as a superior thermal insulating product and it was adopted by clothing and footwear companies and has been used in gloves, boots and of course coats and parkas. After a while, engineers tested its acoustic barrier properties and it performed great and is used in appliances (diswashers). Now, auto makers are studying it for automotive sound insulation where its light weight is a premium feature. Lab guys sent me a sample to try in speakers, but that was after my last major speaker build. Glad it worked for you.
The white fiberglas that Thomas referred to is, I think, Johns Manville brand.

[Coconutout]

I found the 18mm thickness to be too much damping for the woofer cabinet. Lining the walls with single sheet gave me the similar result to an overstuffed box. It is simply too effective. I think that 13mm could be the ticket and will be ordering a sheet of it asap.