So, I stopped by the place that sold me the "semi-cured" rubber sound insulation to get a product reference. The dude wouldn't give me any info, only that he could get as much as I need, and ship it anywhere (welcome to France!).

But... He did spill the words "masse polymère"... And that was enough: I have cracked the case... 

Check this out : http://www.texsa.com/index.asp?i=3&prod=14

Looks like they even have a US distributor.

Before finding this site, I translated a French site, which I might as well include here :

"Range of high density visco-elastic (without bitumin) synthetique membranes. Available with or without adhesive backing, permitting the direct application to different types of substrates.

Intended for acoustic insulation of inclined roofs, vertical walls (either periferal or internal), ducting, floors and ceilings.

With adhesive backing : Tecsound S 35/ 60/ 70/ 100 and Tecsound SY 50/ 70

Without adhesive backing : Tecsound 35/ 60/ 70/ 100

Also available : 

A composite laminate including a layer of sound absorbing felt : Tecsound FT 40/ 75/ 55AL

A composite laminate including two layers of sound absorbing felt and one layer of visco-elastic synthetique membrane: Tecsound 2FT 45/ 80

Available in thicknesses from 1.8  to 24 mm"

http://produits-btp.batiproduits.com/Texsa/Tecsound/fiche/r?id=1543720266

Voilà!

jd*

DERRICK wrote:

Although I think that Romy has voiced some fair criticisms (bearing in mind that he has not heard these speakers, I am sure that he would moderate his opinions if he were to hear them.

Derrick, you might be wrong about it. You are new at my, site let me I explain to you how it "works".

It is not a conversation that I might be impressed or disgusted if I heard these speakers. From something that you have said I presume that I will not like them but publicizing my reaction and my reasons is not what is important. The important part, as I can see it, is to use the experiences of others as an educational method. At this site you will see a lot of commentaries about different steps different horn people took. Do not pay attention to the concussion if you do not like them – pay attention to the reasons and rational - they are always presented. Yes, they are speculations and attempt to assess the things – it shell be understood as such.  I can assure you that if I hear many of the solutions that I criticize then my negativism would be MUCH harsher – I am taking for my past experiences ….

Now about your comment that I might moderate my opinions if I heard any given speaker. I think you have a bit shallow few of the dilemma. The ONLY reasons I might be open in my criticism is because I did not heard the loudspeakers.  Look at the reality how people can get familiar with the sound of speakers. It might be at public arena (show, public demo rooms) or during private visits.  If you paid attention I never (unless the people are dead) make public comments about private visits of audio people or about the private accommodations the some dealers made to me. In fact some dealers made some accommodations for me ONLY with attached condition that I will not pass public comments bout what they demonstrated to me. As far as the private audio visits – the audio people are VERY insecure and have completely fucked up perception of constrictive criticism. So, in most cases if I did hear let say an acoustic system then it very much closes the door for me for expressing my analyses about the performances of the given acoustic system.

So, if to look at subject a bit wider then I hope you will understand now that  the fact the I never heard a given speaker is not necessary a problem. If you heard the drivers and have a grip how the different topologies work then you can pass a relatively accurate predictions but ONLY if you never heard it. If you did heard it and have evidences that Sound was horrible then … you can’t express your opinion as it would violate the “audio friendship”. It is not my rule; it is how the audio people live, unfortunately…

So, think again when you “accuse” me that I did not near the things… I think the criticism, as I use it, is not the criticisms but rather exchange of reasons and rational about horns design.