John Sayers' Recording Studio Design Forum Archive

hi im from Bangladesh. Insaa Allah, im building a small studio at the city Dhaka ,the CRoom dimension is 19',6" by 12',6" and live room (for drums) 14'.6"by 12',6".
in our country the type of fiberglass that is said over your tutorials or over the forum is not available(pink r-13/30 that is 4").my understanding reading the forum is, it should around 45-60kg/QM for insulation. here ,available is glass wool (yellow 1"or 2")density:20kg/QM or 16/QM accordingly and rock wool 2",4". density :=>120kg/QM .the rock wool is very very expensive here

so , im confused. what should i do? can i use double layer of 2" glass wool or 4 layer of 1"glass wool or 2" rock wool is better?
hopefully, im not breaking any rules of posting......

why a handbag commercial is here?...................crazy!!!nutz!!!

why a handbag commercial is here?

Yeah, it happens sometimes. The new spam filter that John installed is pretty good, but every now and then a spammer gets through. And the spam get's removed very quickly! And the person gets banned permanently. So if you see spam like this, just let one of the moderators know, and we'll take care of it.

Anyway, about your question:

in our country the type of fiberglass that is said over your tutorials or over the forum is not available(pink r-13/30 that is 4").my understanding reading the forum is, it should around 45-60kg/QM for insulation. here ,available is glass wool (yellow 1"or 2")density:20kg/QM or 16/QM accordingly and rock wool 2",4". density :=>120kg/QM .the rock wool is very very expensive here

Use the yellow 20 kg/m3 stuff. That's close enough that it will work OK. It's actually not really the density that matters, but the gas flow resistivity. It turns out that fiberglass with a density of about 30 kg/m3 is ideal, and mineral wool (rock wool) with a density of about 50 kg/m3 is ideal, but in both cases there's a range of densities where the gas flow resistivity is still good, and for fiberglass you should still be getting a decent amount of absorption with 20 kg/m2. Just use it a bit thicker, to make up for the lower absorption.

The "rock wool 2",4". density :=>120kg/QM " is way too dense: it won't work well, especially for low frequencies.

So just use the yellow 20 kg/m3 stuff.

Welcome to the forum, by the way! Feel free to start a thread about your build, where you can show what you are doing and ask for advice if you get stuck. That's what the forum is all about!


- Stuart -

thanks! man for the reply ,i didn't know about gas .....(y) ..............so i guess
option1: 4 layers of 1"(20kgpqm)........
option2: or 2 layers of 1"will be sufficient
option3: or 2 layers of 2"(16kgpqm) where thickness is 4"total(if 4" matters more)
....well last two options will cost the same..................any suggestion?

Don't forget that this is density that we are talking about: Adding more layers does not make it more dense: it just makes it thicker. So putting two layers of 2" 16 kg/m3 insulation just means that you have 4" of 16 kg/m3 insulation. The density does not increase.

So I'd suggest using two layers of the 2" 20 kg/m3 yellow insulation: that would be your best bet.


- Stuart -

thanx i have got it now,2" thick 20kg inst available but 1" is.so, i guess it is 4 layers of 1"(20kg)........

Glass whool is thermal insulating agent,while rock wool can also be used in gardening,it is excellent in noise reduction.

Actually, BOTH of them are excellent acoustic absorbers, and both of them are also excellent for thermal insulation. But I'm not sure how you would how you would use either of them for gardening.... Care to elaborate on that?

- Stuart -