fiberglass wool

[pos]

Another potential candidate: Owens Corning's SelectSound Black Acoustic Blanket
It is 25mm thick and 24kg/m3, similar in density to their 701 series.

Soniroll is 28mm thick and around 20kg/m3 from my calculation.

[RMC]

If you are stuck using fiberglass wool from building material stores, like the yellow or pink one, beware of that stuff Inside speaker boxes because it DOES lose many small fibers when handling/tacking. Some may even come out through the speaker port/vent in high power low frequency boxes, plus you could very well find many tiny fibers Inside the woofer's back vent, on their way to the gap ? With that material it is best to wrap it (not tightly wrapped) in cotton cheesecloth to contain the fibers first and before installing/tacking it Inside the cabinet. I've done it and works well. 1" (25mm) may not be thick enough for large woofer(s) boxes specially after tacking it inside the box since it gets thinner after many tacks... In these cases it may be preferable to use somewhat thicker fiberglass wool, like 2" (50mm) or two layers of 1" for example, wrapped together in cheesecloth. I've seen up to 6" thick(!) In a very high power double JBL 2226 low frequency cabinet from Northreading Engineering if my memory is correct...

Richard

[Tony Sullivan]

If you are stuck using fiberglass wool from building material stores, like the yellow or pink one, beware of that stuff Inside speaker boxes because it DOES lose many small fibers when handling/tacking. Some may even come out through the speaker port/vent in high power low frequency boxes, plus you could very well find many tiny fibers Inside the woofer's back vent, on their way to the gap ? With that material it is best to wrap it (not tightly wrapped) in cotton cheesecloth to contain the fibers first and before installing/tacking it Inside the cabinet. I've done it and works well. 1" (25mm) may not be thick enough for large woofer(s) boxes specially after tacking it inside the box since it gets thinner after many tacks... In these cases it may be preferable to use somewhat thicker fiberglass wool, like 2" (50mm) or two layers of 1" for example, wrapped together in cheesecloth. I've seen up to 6" thick(!) In a very high power double JBL 2226 low frequency cabinet from Northreading Engineering if my memory is correct...

Richard

If you are worried about fibers coming out of ports buy an extra large can of cheap extra hold Tammy Wynette approved hairspray and have at it
Much easier and more effective

[RMC]

Hi Tony,

The hairspray is not a bad idea. But then I'd rather use a can of black flat spray paint, possibly less sticky to the touch and more durable for the long run (non-glossy in case seen through the port). In my mind, the important issue here with those sprays is just a very thin coat (see-thru), just enough to contain the fibers in place, and avoid making a hard surface "crust" on the wool by applying too much spray (i.e. keeping the wool soft for absorption.)

I'm more worried about fiberglass fibers inside the driver's back vent possibly making their way to the gap...

Richard

[2$Bill]

As an installation tip, a person on another forum shared a tip that I used. Buy some women's panty hose and put your arms down the legs and you head in the middle. Works great.

[Ed Zeppeli]

That may frighten my children.

[dn92]

I don't know if this will be easier for you to get, but Isover Soniroll Confort is the closest thing to what JBL currently uses that can be found in France.
It only comes in 16m2 rolls, and is pretty expensive...

It the one I'm using. It seems to generate less particules in the air than traditional fiberglass wool, even if you have to wear a mask when cutting/placing it.

As it is expensive you have usely to order it as it is not in stock. I went to a professional shop in France open to individuals, to get it (http://www.pointp.fr/platre-isolatio...1-2-m-A1615800 ), and I don't know if it is possible to order it there from elsewhere. You can probably have a chance to get it if your delivery address is located in EU. Saint Gobain has subsidiaries around the world. I had a first look at the one from USA, but it seems there are not manufacturing this type of acoustic glasswool.
Anyway there are probably similar product from other manufacturers.

PS: pos, if you need, I should have a remaining length of the roll for your M2 clones.