Drum Room Construction

[lakidog123]

Dear Stuart ,

Regarding the drum room construction conversation that started at Fri Feb 03, 2012 , you mentioned that you can get good results if you built 2-leaf wall using rockwool and gypsum board .

But what if someone builts a drum room using a third rockwool wall in between the other two.

For example : 1st leaf includes double gypsum board , or concrete wall after that continuing with a rockwool board (with no gypsum board on it just the wooden frame around it) , and closing with the 3rd wall of rockwool and double gypsum board .

Keep in mind that the 3 rockwool walls will have minimum 10 cm air gap between them .


Thanks and Best Regards

Andrew .

[Soundman2020]

Hi there Andrew, and Welcome. Please read the forum rules for posting (click here). You seem to be missing a couple of things!

Regarding the drum room construction conversation that started at Fri Feb 03, 2012

Which thread? Please post the link to that thread, so I can see which one you are talking about.

you mentioned that you can get good results if you built 2-leaf wall using rockwool and gypsum board .

But what if someone builts a drum room using a third rockwool wall in between the other two.

For example : 1st leaf includes double gypsum board , or concrete wall after that continuing with a rockwool board (with no gypsum board on it just the wooden frame around it) , and closing with the 3rd wall of rockwool and double gypsum board .

Keep in mind that the 3 rockwool walls will have minimum 10 cm air gap between them .

I'm not sure I understand: Are you saying that your hypothetical "wall in the middle" would just be a wooden frame with mineral wool in it, but no sheathing of any type on it at all? Just empty framing with insulation?

If that is what you are asking, then the isolation would be better than if the middle "wall" was not there (because mineral wool is a good acoustic damper, and would damp any internal resonance that happened inside the cavity, among other things), but I don't understand why you would want to build an additional empty frame in the middle of a wall cavity. It would be better to design the wall to have the correct total air gap for the needed level of isolation, the fill that entire air gap with suitable insulation. I don't see the need for the empty frame.

- Stuart -

[lakidog123]

Hello Stuart,

Thank you for your reply. It was just a thought of mine, thinking that this might gain extra sound isolation. Thank you for your advice on this.

By the way, if you could also help me with something else, I am building a sound proof booth in the basement of my store.

The floor is concrete, so obviously no floating floor.

However, whereas I have read that the studio construction sticky (beeros), and learned a lot of things from this, how things work, thank you again for this, the guideline should be as follows:

1. First construct the ceiling?
2. Secondly the walls, that are firstly attached to concrete floor and then to the ceiling? That is the thing I am not sure about. Should the walls attach to the ceiling or should there be a
small gap between.
If so, what size gap? I know that then it should be filled with acoustic sealant. Is this correct.

The size of the bare room is 3,5 m by 3,5 m and 2,6 m height, and will be used for guitar/amp demo.


I would grately appreciate your help with this.

Kind regards.


Andrew.

[Soundman2020]

2. Secondly the walls, that are firstly attached to concrete floor and then to the ceiling? That is the thing I am not sure about. Should the walls attach to the ceiling or should there be a small gap between

If you want a lot of isolation, then build the walls first, bolted to the floor, then build a new ceiling on top of those new walls. The new ceiling cannot touch the original ceiling at all: no nails, nothing. Just put joists across the top of the new walls, then put drywall on those joists. Of course, this means you need to plane carefully, so that the walls are just high enough to make sure that things don't touch, and there's a gap up there!

The size of the bare room is 3,5 m by 3,5 m and 2,6 m height, and will be used for guitar/amp demo.

Two of those dimensions are the same! You should never build an acoustic room that has a square section, like yours. 3.5m wide by 3.5m long is bad. It means that all of the modal problems will be multiplies, as the natural resonant frequencies of the room for the "width" direction will be exactly the same as the natural resonant frequencies of the room for the "length" direction. You really should change that. You need a difference of at least 5%, so you need to make one of those dimensions either more than 3.7m, or less than 3,3m.

- Stuart -

[lakidog123]

Hello Stuart,

Once again thank you for your very prompt reply.

I will build the walls first, attaching the frame to the concrete floor. Do I also attach the upper frame to the original ceiling (like in the thread from Beeros on page 3 IMG 1052 jpg?) This is what
I have understood. The new ceiling will be constructed without touching the old one, just on joists with isolated hangers from the original ceiling.

Should the frame that joins to the ceiling (the top frame), also have isolated parts?

The gap you are referring to is the gap between the new ceiling and the new drywall walls. What would you suggest as an appropriate size for the gap in cm or mm?

One last question, the four drywall walls, should they have a gap between them like the same relationship between the floor and the ceiling?

Thank you for your advice on not building the room as a square section. I will try to change the dimensions. If though, let`s say it is impossible for the room dimensions to change, is there
anyway that we can improve the acoustics of the space by adding something after the room is complete, i.e. abosorbers.

Once again your reply will help me a lot. Congratulations on your patience with all of the questions you answer.

Regards.



Andrew.

[Soundman2020]

Do I also attach the upper frame to the original ceiling

No. The new inner-leaf walls are attached only to the existing floor. You build a new ceiling on top of those walls, without attaching them to anything else. Of course, you have to build the walls correctly, so they provide the structural support, but that's not hard to do.

The new ceiling will be constructed without touching the old one, just on joists with isolated hangers from the original ceiling.

That's the other way of dong it! If you do it that way, then the new ceiling is not connected to the new walls, so the new walls will need support. In that case, you would need sway braces at the tops of the walls, to keep them in place. Extra cost, extra complication....

The gap you are referring to is the gap between the new ceiling and the new drywall walls. What would you suggest as an appropriate size for the gap in cm or mm?

That depends on how many decibels of isolation you need, and what is the lowest frequency that you need to isolate.

If though, let`s say it is impossible for the room dimensions to change, is there anyway that we can improve the acoustics of the space by adding something after the room is complete, i.e. abosorbers.

, well, it is possible to treat the room, to a certain extent... but for very low frequencies in a small room, you need a LOT of treatment...


- Stuart -