internal walls concrete block question

[mart1977]

Hi all

I'm in Ireland and our building practices are generally that all houses and buildings are concrete - normally concrete block. What are the advantages and disadvantages of using say double 4" spaced concrete block on inner walls separating control room from recording room and any iso booths.

Concrete block should have an advantage in terms of mass and cutting down sound transmission over stud and plasterboard. However I've heard talk that the 'give' or resonance in plasterboard membrane has a damping effect as sound passes through the leaf to the next layer - whereas concrete block reflects back as it has no damping qualities.
One other thing about using concrete block would be getting separation between the inner leaf walls at the foundation which might have to be decoupled some way.

Most of the builds I've seen here and in books use stud partition walls but occasionally I see control room walls in concrete block separating the live room from the control room.

thanks

Martin

[Soundman2020]

What are the advantages and disadvantages of using say double 4" spaced concrete block on inner walls separating control room from recording room and any iso booths.

There are many advantages! Mainly the excellent isolation you would get like that. The only disadvantages are the thickness of the wall, and the cost. But if this is the normal way of building where you live, the cost is probably not that high.

Concrete block should have an advantage in terms of mass and cutting down sound transmission over stud and plasterboard.

Correct!

However I've heard talk that the 'give' or resonance in plasterboard membrane has a damping effect as sound passes through the leaf to the next layer -

True, but the effect is small, and it can actually work against you under certain circumstances. IF it acts like a membrane, resonating at some frequencies, then it is storing energy at those frequencies and will continue to resonate and "ring" after the tone has stopped, sending the same tone back into the room... so the room structure extends the tone and the decay time beyond what is in the music, and the room carries on playing after the music has stopped.. not what you want in a studio.

whereas concrete block reflects back as it has no damping qualities.

True, but it does not matter. The huge mass is sufficient to outweigh the minimal damping.

One other thing about using concrete block would be getting separation between the inner leaf walls at the foundation which might have to be decoupled some way.

Not necessary, unless you need extremely high levels of isolation.

Most of the builds I've seen here and in books use stud partition wall

True, and that's for two main reasons. One is that this type of construction (stud frame and drywall) is the cheapest in most places around the world, and the other is because it is very well understood, and simple to predict performance, for the same reason. Because this is such a common method, it is also the one that has had the most research done on it. But there is also research on other methods, such as what you propose.

A wall built with two layers of concrete block separated by a 4" air gap filled with suitable insulation, will get you around 60 dB of isolation, and you would have isolation all the way down to 21 Hz. That's excellent! That's about as good as it gets for home studio construction.

What you propose is an really good method of doing things. It takes up more space, yes, and might be a little more expensive yes, but it will give you really good isolation. Your biggest challenge here would be to design the ceiling, windows, doors, HVAC system and electrical system to the same high level of isolation!


- Stuart -

[mart1977]

Thankyou Stuart that gives me confidence with the potential design I'm sketching. I will begin posting it for input when I get to grips with sketchup!