High density sound proofing

[publius]

Hi everyone, this is my first post. I've been reading this forum's posts quite a while but never found a straight answer to my queries, so here it is...

I'm going to construct a studio with a live room ~32m^2 with a control room ~15m^2 which will be used for rehearshing and recording, however there some drawbacks in the design

1. The rooms are already constructed about a decade back when the house was constructed and cannot be modified since these walls are part of the foundations.
2. The height is only 2.5m which is very low
3. The floor above the live room is a dining room which is marble while the whole house is constructed with concrete armed cement as most houses in my country are build this way.

The list goes on...but there are also some advantages...I own the place

So what I'm trying to do is to totaly isolate the live room from the rest of the building so that external ambient sounds or noise does not enter this room but more crusial is that 'noise' made in the live room does not escape to the other floors.

Since the height is very small I am examining materials that may have small width but very high density and I found two materials sold in retail in my country, the Ecorubber and the Isolgomma. Both these materials are made from pressed rubber fibres and granules and both have a density of 700-800kg/m^2.
Therefore my query is...
...does such high density means that the mass is also high?
Has anyone used such high density materials for sound insulation, what's your opinion?
I know these materials are expensive but do these get the job done?

[Bill Pillmore]

What country?

[gullfo]

please update your profile with your location information and read the read-me stickies which will guide you on how to provide enough information. as a general note, common 16mm type X drywall is 600-700kg/m3 and is likely less expensive.

[Soundman2020]

There is an announcement at the top of the forum about what to do to assure getting as many responses as possible.
The announcement leads to this post (click here). Actually, several people, who are experts on this forum, will most likely not reply if you don't do what is written in that post.

... as most houses in my country are build this way.

??? and that country would be ???

Both these materials are made from pressed rubber fibres and granules

Sounds like typical MLV to me (Mass Loaded Vinyl) or something similar. Very expensive mass. Not normally recommended here. Sound waves don't care how much you pay for the mass, so get the cheapest mass you can.

have a density of 700-800kg/m^2.

Are you talking about surface density, or density? Different things. kg/m^2 is surface density. kg/m^3 is density.

...does such high density means that the mass is also high?

Depends on teh thickness, if you are talking about surface density.

In any event, the thickness of the mass isn't that much compared to the dimensions of the framework that you will need to support it.

For example, if you put a single layer of 4 mm steel plate on 2x6 studs or a single layer of 16mm drywall on 2x6 studs, the total thickness of the ceiling only increases from 169mm to 181mm, or about 9%. Not really useful, for all the extra effort and cost.

Has anyone used such high density materials for sound insulation, what's your opinion?

Yes, it has been used. No it isn't recommended, due to the cost. And no, that isn't very high density. Aluminium, steel and lead are all much denser. So is ordinary window glass. Even drywall is about the same, as Glenn pointed out.

I know these materials are expensive but do these get the job done?

Probably not. How would you seal it anyway?

If you want material that is denser than drywall and still not too expensive, take a look at fiber-cement board. Its about twice as dense as drywall, and only a bit more expensive: Not fun to work with, though....

If you are concerned about ceiling height, then you should probably consider building your entire room inside-out.

- Stuart -