Need Help about Studio construction!!!

Hello everyone, Great site and Great forum,lots of useful information and lots of things to get stressed for..... Anyway,we are building a Recording/rehearsal studio on a basement and we have plans for 3 rooms:Control,recording and rehearsal. We got in touch with a specialist company in studio design and they prepare the whole sound insulation design. The basement is 150m2 and our main problem is that due to space restrictions,the rehearsal room will be next to recording room and we want to be able to use both at the same time!!!!!! Of course we wonder if something like that is possible. The guys from the company decided a room in a room design for each of the 3 rooms based on 3 concrete floating floors standing on elastic pads(Silomer).For the walls they recommended us 2 gypsumboards of the same size(12,5mm)and rock wool for all of the walls except the partition walls(Control room-Recording room and Recording room-Rehearsal room) where a 3 gypsumboards(of the same size again) design has been chosen. In both rooms the drums will be on a pedestal filled with rock wool and standing on pads. I must tell you that we already have finished the 3 floors and they look great but..... Searching on this Great site again and again I now have a lot of worries especially as far as it concerns the gypsumboards/rockwool design they proposed us. For example:shouldn't the 2 gypsumboards to be of different size,one 16mm and one 12,5mm? Are 3 gypsumboards more effective than 2?I read in a topic here that 2 are more effective for the dreadful low frequencies while 3 are suitable for the high freq. I would really appreciate any help you could offer because we already have lost money and time in a total wrong design and now we start one more time from the beginning :(

read this viewtopic.php?f=17&t=7572

First, please do what John said. But a couple of comments are in order:

they prepare the whole sound insulation design

I think you mean "isolation" not "insulation". It might seem like a minor point, but precision in using the right term is actually very important, and can save you a lot of heartache later! Insulation is pink fluffy fiberglass or mineral wool. Isolation means to stop sound getting in and out, and is also incorrectly called "soundproofing".

... based on 3 concrete floating floors standing on elastic pads(Silomer).

:shock: While that will certainly work (if it is done correctly), it sounds like way overkill for what you are trying to do, and I sure hope you have a LOT of money to do it! Take a look at these to get an idea of what that involves: viewtopic.php?f=2&t=8173 http://www.nrc-cnrc.gc.ca/obj/irc/doc/p ... /ir802.pdf

For the walls they recommended us 2 gypsumboards of the same size(12,5mm)

Bad idea: 12.5 mm too thin, too flexible, resonant frequency is too high, mass is too low. Use only 16mm. But I don't get this: they want you to float concrete floors, but then only use 12.5mm drywall???? Huh? :shock: Makes no sense. Major big-time expense on the floors, but then flimsy low-isolation partitions for the walls???

I must tell you that we already have finished the 3 floors and they look great but.....

so that must have set you back many tens of thousands of dollars already! Wow! Pity you didn't come here first: you probably could have saved a LOT of money. Maybe you could post some photos of how those floor were floated?

For example:shouldn't the 2 gypsumboards to be of different size,one 16mm and one 12,5mm?

They should BOTH be 16mm. 12.5 is too thin, for the reasons mentioned above.

Are 3 gypsumboards more effective than 2

Yes!

I read in a topic here that 2 are more effective for the dreadful low frequencies while 3 are suitable for the high freq.

Actually, it's the other way around: 2 is probably enough for highs, but 3 is better if you have low frequency problems as well.

I would really appreciate any help you could offer because we already have lost money and time in a total wrong design

Yes, folks here WILL help, but please abide by the rules first! Read the post that John linked to, do everything he says there, then post your diagrams, plans, photos and other details. Then we can help you. If you don't explain and show clearly what you have and what you need to do, then nobody here can help! - Stuart -