Recording Studio in Brazil

hello everyone soon I'll start building my own studio I already have in mind more or less what I want to do but I like to have some advice and ideas basically the studio will have 3 foundations built separately (physically separated to avoid problems related to isolation between foundations; +/- 1m – 2m between rooms) 1st control room (H x 3.5m W x 4.5m L 5.5m) 2nd recording room (H 4,5m x W 5,8m x L 6,9) 3rd room recording / rehearsal room (H x 4.5m W x 5.8m L 6.9) The contact will be made via windows the size of the rooms have been chosen according to the Sepmeyer criteria to avoid the most possible modal problems The 3 buildings will be constructed with concrete blocks in order to keep a good STC In the 3rd room which also will be used as a rehearsal room, I would like to have a more neutral room I'm thinking about wooden floor and for the ceiling, wooden strips fixed over the fabric layer , with spaces between them which would allow a good proportion of the lower frequencies to pass into the absorbers behind It would be a trapezoidal room to avoid flutter echo A wall : plywood B wall : plywood and a heavy curtain to be able to change the acoustics C wall : absorbing wall D wall: Diffusive wall, with absorbers between diffusing half-cylinders and if needed some bass traps to maintain the level of all reflections It would be a trapezoidal room to avoid flutter echo I would like to keep the reverberation time around 0,7 sec For the 2nd room I would like to have a room if more characteristic acoustics. I was thinking to keep the same shape of the 3rd room,but rise the reverberation time to around 1,5 sec. I would like to be able to vary the sonic characteristics... I was thinking to have one brighter corner made of stones, the other sides made of wood with some rotatable diffuser/absorbers to change the acoustics. I know that I must use some heavy absorbers to maintain the control of sound,especially for low frequencies I'm open to ideas and suggestions because I want to avoid errors

Hi Fernando. Please read the forum rules for posting (click here). You seem to be missing a couple of things! :)

basically the studio will have 3 foundations built separately (physically separated to avoid problems related to isolation between foundations; +/- 1m – 2m between rooms)

Do you really need such enormous isolation? Very, very few studios need anything like that. Why do you need so much? Is this going to be a Foley / ADR studio? I can't think of any other reason why you would want to have such huge separation between rooms. 1 meter between foundations? :shock: :!: Even in the most extreme cases of isolated slab construction, people normally only have a few millimeters between slabs. Maybe a centimeter or so, max. I can't think why you'd need a meter.....

1st control room (H x 3.5m W x 4.5m L 5.5m)

That's a good choice. Very close to Sepmeyer's 2nd best ratio.

the size of the rooms have been chosen according to the Sepmeyer criteria to avoid the most possible modal problems

You don't need to worry about ratios too much for the live rooms: only the control room.

The 3 buildings will be constructed with concrete blocks in order to keep a good STC

STC is not a good system for measuring studio isolation. It was never designed for that. It is reasonably useful for measuring isolation of typical home and office sounds, but not for loud music. Use TL instead.

I'm thinking about wooden floor

You said the floors were going to be concrete slab: That's the best possible floor for a studio, so you don't need to put anything an top of it. If you pour the concrete well, and get it flat, level and smooth, it can be an excellent surface for a studio. Or if you don't like the look of concrete, then just put laminate flooring, or tiles, or something similar on the concrete. But do not build any type of wooden floor over the concrete if it has an air gap in it.

and for the ceiling wooden strips fixed over the fabric layer, with spaces between them which would allow a good proportion of the lower frequencies to pass into the absorbers behind

I think you probably need to study acoustics a bit more, to understand why that would be a bad idea. I'd suggest that you read the book: "Master Handbook of Acoustics" by F. Alton Everest. But to summarize, since the studio floor will be hard, solid and reflective, the ceiling should be mostly soft, fluffy and absorptive. Or else you will have flutter echo problems between those two surfaces. Placing wooden slats on your ceiling would create reflective areas. Slats are fine for the walls, if done properly, but not for the ceiling. Take a look at photos of world-class professionally designed studios, and see how many have large slats on the ceiling. You might find that in small booths, or even drum rooms, usually in the form of a binary diffuser or something similar, but you very seldom see that in large live rooms.

It would be a trapezoidal room to avoid flutter echo

That's fine for the live rooms, but the control cannot be like that: it MUST be symmetrical. If the control room is not symmetrical, then your left and right ears are hearing different acoustic environments, and you will never be able to create a well balanced stereo mix. I would suggest that you research RFZ control room design. Also, flutter echo can be eliminated in several other ways: you do no need to angle the walls to do that. There might be other reasons to angle them, but flutter echo is not usually one of them.

I would like to keep the reverberation time around 0,7 sec

For a control room that size, it should be more like 250 ms. For the live rooms, 700 ms is a possibility, but what will the live rooms be used for? That would be OK for guitar or even drums, but pretty bad for vocals.

I was thinking to keep the same shape of the 3rd room,but rise the reverberation time to around 1,5 sec.

Do you record a lot of church organ music? Gregorian chant? Taiko drums? That's a pretty long decay. Getting well into concert hall territory... It would be pretty hard to get such a long decay time in such a small room as well: You'd need to make all the walls, the ceiling, and the floor very reflective, with overall absorption coefficient for the entire room of less then 0.1.

I would like to be able to vary the sonic characteristics...

That is possible, yes. There are several ways that you can make your acoustics variable. You do that by covering or uncovering large areas of absorption or diffusion. - Stuart -

First of all ... thank you for the Answer and sorry for my bad english. I saw that I've to put my budget...I don't really have a budget for that I was thinking about 1m between the foundations just because I've the space for that,but I'll decrease the space for about 5 cm – 20 cm. For the floor of the rooms I was thinking of using wood for aesthetic and the look... and when I said wood I was thinking of laminate flooring...LOL but I didn't know that the concrete slab were that good. I 'll probably use laminate flooring for the control room and leave the concrete slab for the recording rooms When I said wooden strips for the ceiling I was thinking about Convex Diffuser Panels like those used in “Galaxy Studio” in Belgium The shape and reverberation time are for the recording rooms I know that the control room must be symmetrical and I'm planning to use the RFZ design But for the recording rooms is it better to have an asymmetrical shape or have a rectangular room and and only then change it "shape" with diffusers, etc ? For the reverberation time I'll maintain it around -250ms for the control room -500ms for the 3rd room -700ms for the 2nd room And for vocal I'll use a portable vocal booth Do you think that's a good idea to mix stones and wood in order to have a “live” room with plenty of characteristics?

For the reverberation time I'll maintain it around -250ms for the control room -500ms for the 3rd room -700ms for the 2nd room

Great! Those are fine.

Do you think that's a good idea to mix stones and wood in order to have a “live” room with plenty of characteristics?

Definitely! You could have one section with stone, another with wood, another with just absorption, and another with just diffusion, then you can play around: try out each instrument in different locations and orientations, to see what sounds best. Also make some "gobos" that you can move around, to give you more flexibility. That's a really beautiful location you have there! Wow. Lucky guy! :) - Stuart -