John Sayers' Recording Studio Design Forum

Hi Friends,

I intend to build a recording studio with the space I have (in Bangalore, India). This space is located on the third floor of a residential building that my family owns. It has been built recently. There are two rooms located on the floor above me, and there are families living in the floors below mine (rented out).

With regard to soundproofing, I am very much concerned about outgoing noise that could disturb the other tenants who live below me.

I have a space of 735 sq ft. I have made a rough drawing of it and I have marked all the dimensions I could think of. There are no windows in the space that I intend to use as the studio, but there is a bathroom and a bedroom that I have built which has windows, but this would fall outside the 735 sq ft that I mentioned.



Regarding Materials used for construction: The whole building has been built out of concrete blocks, followed by 1/2" plaster on each of the faces. This applies to walls/ceiling/floors. The exterior wall width is 6" of concrete block + 1" of plaster. The walls around the stairwell are slightly less wide - 4" of concrete block + 1" of plaster.

Current state: All exterior walls have been constructed. The bedroom and the toilet too has been constructed and ready-to-use. So I now have 735 sq ft of concrete enclosure.

My plans so far:
I want to construct a double leaf system for the walls. There will be an interior wall made of gypsum board supported by a wood frame, with an air gap of 6". That is, 6" from the inner face of the gypsum board to the inner face of the concrete wall. This will be filled with fibre glass slabs or rock wool.

I have not planned for any sub-rooms. I don't want to have any partitions. One big room that sounds great is what I am going for.

Inner Ceiling will be same as the wall design. I have not put much thought into ceiling details yet.

I don't know what to do with the floor. There are many posts on floating floors and whether it is necessary. In my case, I am not sure, because my floor is 7" of concrete. I intend to rent this place out as a jam room for bands (most of them would play rock and metal), so there will be a lot of drumming and bass going on. I also would be using this place to record music, not just bands, but also ads/jingles and my own stuff and films in the future.

I have thought about building platforms for the drumkit and bass/guitar amps as an alternative to floating floors - is this a viable option?

I would like to hear your thoughts regarding the following concerns:
1. What do you think about an all-concrete enclosure? Is it a great start to sound proofing the place or does it not matter?
2. What can I do with the flooring that will help me run the place in peace?

I have been reading and researching about studio construction for almost a year. I realized very recently that I might have an advantage because of the concrete and plaster. Most of the sound proofing articles assume that the walls are made of drywall or similar board. I read this article - http://www.nrc-cnrc.gc.ca/obj/irc/doc/ctu-n13_eng.pdf - that gave me this hope.

I measured the weight of one of the concrete blocks - it was 17kg. The measurements were 4" x 8" x 16". (this is not the same one used in my building, but the mass per unit area should be same)

I am going to do some measurements of how isolated the current space already is? Any ideas? I already have an SPL meter. I want to be able to play music at 100db inside the space and not disturb anybody.

Thanks for this great forum and for allowing me to post here! Awaiting your comments!

Regards,
Vimal

Hi Vimal, and Welcome!



I don't know if you have seen these threads. If not, you might find them interesting.

viewtopic.php?f=2&t=8173
viewtopic.php?f=2&t=8134

This paper also deals with floating floors, so you can get an idea about different ways of building them, and how that works out in practice:

http://www.nrc-cnrc.gc.ca/obj/irc/doc/p ... /ir802.pdf


Your concrete block shell should be giving you pretty decent isolation, just like it is. Probably around 45 dB. However, that's for airborne sound: structure-borne sound is another thing entirely. For example, gently tap on the wall of one room with a hammer, and you will easily hear that everywhere on the building. Stomp on the floor, and that too will be heard everywhere. That's what drummers do: they stomp on the floor with every kick and hi-hat beat. Low frequency vibration from bass cabinets sitting on the floor will do the same. Once this type of impact noise gets into the building structure, there is nothing you can do to stop it, so the key point is to prevent it getting in. For a ground floor room, this isn't too much of a problem since the concrete slab is damped by the earth below it, but in your case you are on the second floor, and there is only air below you.

Yes it is an option: that's usually called a "drum riser", and if built correctly it will keep all that kind of impact noise out of the building structure. Obviously, it is not as good as a floating floor, but it certainly does help a lot.

It is an excellent start!

Four options: 1) Do nothing at all. 2) Build a drum riser, and a smaller pad for the bass amp. 3) Build an isolated floor. 4) Build a full floating.

That's probably not a realistic estimate. The drums alone can put out 115 dB, and by the time you add in several other loud things, you are getting really close to 120 dB peaks. Your existing wall should be getting that down to around 70-something, so you still need more isolation. I'd suggest building a fully decoupled 2-leaf MSM "room within a room", designed to give you about another 25 to 30 dB of isolation.

That would be my suggestion.

- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.