what happens if you double it???

Hi everyone, I just bought 2 packs of rockwool 3inch for acoustic treatment in my very paralle room. (lol) I was wondering, if I put 2 pieces of 3 inch rock wool one on top of each other (by gluing them or just tapping them... I dunno), will the bass absorption be better then a single 3inch? I am guessing that 2x3inch = 6 inch so you would have a very good bass absorption like 6 inch pannels... am I wrong? Please help me francois (by the way, how much does rockwool cost around the world? it's darn cheap in canada! It's the equivalent of 25-30 cents US per square feet)

Please help me

where the f.... are you coming from?? we showed you how to fix up your tiny bedroom - now go and build it please :roll: cheers JOhn

??? I am now to the point where BUILDING is not a problem anymore but the ACOUSTICS are my main interrests now. The room is almost finish building so I was just wondering if 2 pannels of rockwool one on top of each other absorb more then 1... sorry for bothering... If anyone want's to answer kindly, I will strongly appreciate....

Oh, and I forgot to mention that where I live (canada, quebec) the sentenec PLEASE HELP ME is not considered as HARMING so the F word could have been facultative...

tenkas wrote:

I am guessing that 2x3inch = 6 inch so you would have a very good bass absorption like 6 inch pannels... am I wrong? francois)

No you are right, and when putting 3 inch with a cavity of 3 inch then it's also about the same as a 6" panel. The bottom 3 inch acts more as an acoustic transparant layer. So you can check what's cheapest: Wall + 6 inch Wall + 3 inch nothing + 3 inch material (must have some distance keeper).

tenkas wrote:

(by the way, how much does rockwool cost around the world? it's darn cheap in canada! It's the equivalent of 25-30 cents US per square feet)

Rockwool cost per weight/amount of spinned fiber + roughly fixed cost for handling, package and transport in function of volume. So price is VERY dependent on density. (and of course local market circumstances). :roll: So nobody can answer your question without more detail. And if labor cost is comparable, production method is also comparable, then prices won't differ that much. Rockwool is standard about anywhere and prices are controled by the price level of competitive products also. Regards Eric

Tenkas, try this on for size, I live in Michigan and rockwool (3") is about 25 censt a foot, the denser stuff is about .35 cents a sq ft. So our prices are similar. If someone is paying more, I;d have to blame it on shipping costs. My Nearest factory is about 4 hours away from me. Bryan Giles

francois - forgive me for my stupid outburst - full moon, too much red wine etc. :):) Eric has answered your question properly as usual - thanks Eric. cheers john

well I know you guys are very patient with all of us amateurs. You are giving away free knoledge and this is something I respect. I just didn't expect that kind of reply but heh... it's ok... If you want to answer another question (probably my last one before I really finish my room), here it is: (go see link at bottom first) In the bottom right corner of my room, there are shelves that arrive flush with the continuity of the bottom right wall (you still with me???). I would like to know if putting rockwool bats (covered in garbage bags) perpendicular to the shelves (has if the rockwool would be a wall) without sealing anything would make that a good bass trap. The bats would be about 1 foot from the wall (bottom right). I am sorry I can't post an image right know because I am not at home but here is a link to my room : http://membres.lycos.fr/tenkas/basement.gif To summarise, I would like to know if putting rockwool NON SEALED would created good absorbers. I just want to know if I have to cover EVERY inch of the parallele walls with rockwool or can I leave 1 foot spacing between the rockwool pannels? This seems confusing but I am sure someone will get it :P If not then I will try to make a picture soon, but I am really in a big school rush so it's hard! Thx a lot guys again for everythinkg

Yes I remember your room - yes - if you remember Steve in his first post to you actually suggested your rockwool line to go over that depth because of the benefit of being "off the wall" cheers john

ok! Thx a lot! it's just that I didn't drew the shelves so I didn't know if the shelves would have done any acoustic difference, so I will now go and finish the basement. when my room will be finished, I will tell if garbage bags are good or not to cover rockwool :P thx a lot