Finally building my own Studio

Hi, I am new to this Forum. I have been reading alot of your posts and am really happy to have found this. I started planning my Studio a few weeks ago. I bought books and started thinking about geometry ect. ect. I found a couple of excellent construction diaries here as well as on gearslutz. I used to work as a studio planner, however my company was only concerned with the technical aspect of the design, meaning I am a newbie with the whole construction thing. Ok I would really like to turn this thread into a diary in the end, however first of I need to get the whole thing planned out in order to start (well I started a little already, got too excited :) ). Let me explain What I want to be doing first. I want to build a small ( about 45 sqm) recording studio, with a recording, a mixing room and two small booths. The room itself is sited in a residential area, "downtown" Munich (Germany), if there is such a thing. It is in the ( I always get confused with first, second ... floor because it is different in germany so I will call it) ground Floor. I have someone living ontop, a basement underneath and two joined walls with the buildings next door. The basement is empty and all the other walls either adjoin a garage or open space. The ceiling height is 3,15m, which is nice and since the builing was built in 1901, I have very thick brick walls (>45cm). Now I am thinking of the best geometry. I know of trying to avoid paralell walls. I tried to calculate a couple of wave paths to have an area of no reflections on the mixing position. As I said I have read a couple of books. My first and maybe biggest problem is the floor. It has a step right where I wanted to have the wall between the mixing and recording rooms, which would not be so bad, if I didn't want to have two small booths there for vocals and guitar cabs. This means there would be a step or I would have to even out that part of the floor or even out the whole floor. Another consideration I am not exactly sure about is floating the floor. How do I do it? Or do I even have to do it? I just read this excellent post (viewtopic.php?f=2&t=8173&start=30) and now I am not sure anymore if I would really need it. Of course I would prefer not to, since the budget is tight, but who am I telling this? whos budget is not tight? I uploaded this simple plan, because I am new to sketchup (great great software),too. I am really hoping to get some feedback, because I just hate wasting money on something that could just have been planned better. Don't you? So please, if you have suggestions don't hazitate. Thanks P.s. I am german so please excuse my english if it is not 100% understandable

Welcome, I'll have a look at your drawing and give some suggestions... Cheers, John

Grossstadtlegende wrote:

...ground Floor. I have someone living ontop, a basement underneath and two joined walls with the buildings next door. The basement is empty and all the other walls either adjoin a garage or open space. The ceiling height is 3,15m, which is nice and since the builing was built in 1901, I have very thick brick walls (>45cm).

With the thick concrete walls you will probably get about 50db transmission loss. I wouldn't worry too much about the floor, unless you are cranking hip-hop...

Grossstadtlegende wrote:

Now I am thinking of the best geometry. I know of trying to avoid paralell walls. I tried to calculate a couple of wave paths to have an area of no reflections on the mixing position. As I said I have read a couple of books.

Honestly, the luxury of slanting walls should be reserved for those that have the space to waste. 1. they do not improve the standing wave distribution but only make them harder to calculate and trap. 2. wasted area (already mentioned) and 3. there are more efficient ways to treat for flutter echo.

Grossstadtlegende wrote:

My first and maybe biggest problem is the floor. It has a step right where I wanted to have the wall between the mixing and recording rooms, which would not be so bad, if I didn't want to have two small booths there for vocals and guitar cabs.

Try putting the booths at the back of the live room. ?? Make the CR window smaller. Not a good idea to have that much glass. May I suggest these dimensions: CR = 523cm X 440cm X 315cm... Live room (including booths) 440cm X 266cm X 315cm. These dimensions result in an excellent modal response in both rooms. You can put booths in the back corners of the live room. Question about vocal booth. Do you need it because you are recording the entire band together and need a scratch vocal to keep everyone one track?? If not - you don't need a vocal booth. record the vocal in the big room surrounded by gobos to dry up the room sound. You will get a 'bigger' sounding vocal without the boxy booth anomalies that always accompany booth vocals. I looks like you are going to have some fun. enjoy! and good luck. Keep me posted. (... where's my pipe??) Cheers, John

jhbrandt wrote:

With the thick concrete walls you will probably get about 50db transmission loss. I wouldn't worry too much about the floor, unless you are cranking hip-hop...

I was planning on doing an extra layer of gypsum board on the outside walls anyways, I do not want any neighbours complaining :) So the Isolation should be fine, right? I want the studio to be rented, so I will only work in there when it is empty. This is why I do not know what kind of music will be recorded in it. I guess mostly rock/metal. And I would really like to keep the two booths, because recording simultaniously saves so much time. As you can see in this picture, I have an old wall in the room, that has been cut out. So I think the wall with the window is pretty much restricted to be where I put it because of this wall. Is lowering the ceiling to 3m or something like that going to help the modal distribution? I will have a friend come over and do a proper measurement of the room (dimension wise) today and will do a new more acurate drawing opf the place.

jhbrandt wrote:

I wouldn't worry too much about the floor, unless you are cranking hip-hop...

As I said, I dont know who will be recording whom in there, so I dont know if it is going to be HipHop. I guess not too much... But you think I do not need to float the floor? Btw. I already got rid of the old wood floor, which was loud just walking on it. My brother took it apart with a chainsaw and the girl living above the studio did not even hear it... Thanks so much for the response! More help than I got out of the books... :) Here are a couple of pictures of the room:

I was planning on doing an extra layer of gypsum board on the outside walls anyways, I do not want any neighbours complaining :) So the Isolation should be fine, right?

One extra layer of drywall over 45cm of solid brick is not going to make any appreciable difference at all. Not even a measurable fraction of one dB! Brick is roughly twice as dense as drywall, so just to double the mass of that wall you'd need to put about SIXTY layers of 5/8" drywall on there, and all of that would only gain you 6 dB of isolation, at the very best, assuming that there are no flanking paths at all. So don't waste your money with that plan If you really do need better isolation, then your best bet would be to build a stud frame about 20cm inside of the existing brick wall, totally decoupled from it, put at least 3 layers of 5/8" drywall on only ONE side of that frame, with Green Glue between the layers, and fill the entire gap between that and the brick wall with mineral wool or fiberglass. Do the same on the ceiling, with the new ceiling resting ONLY on the new stud frame walls. No mechanical contact at all between the new wall and the existing wall. That would make a worthwhile difference in isolation. However, you did not say how loud you are nor how quite you have to be (in real numbers), so it's really hard to say if you already have enough isolation, or if you will need more. You say you have someone living directly above you, so that will be the limiting factor in how quite you have to be, and since you share walls and his floor (your ceiling) there will be flanking going on, which you will need to deal with through decoupling.

Now I am thinking of the best geometry. I know of trying to avoid paralell walls. I tried to calculate a couple of wave paths to have an area of no reflections on the mixing position.

For a reflection free zone (RFZ) you need to splay your inner-leaf side walls by at 6 degrees each (total of 12°) and tilt your inner-leaf ceiling by 12° (lowest at the front of the room, highest at the back). That is assuming that you will arrange your speakers in the "usual" geometry, being an equilateral triangle with a 60° intercept of the acoustic axis a few inches behind your head. However, based on your current design, it looks that would put the listening position at roughly 50% of the room depth, which is a bad idea. You will probably have to tighten the angles on your speakers, perhaps to as much as 90° intercept angle, to get your listening position closer to the 38% general guideline. (It doesn't matter if you can't hit 38% exactly, but as log as you are close to 38% and far away from 50% and 25% then you should be OK.): So if you were to change your speaker angles like that, then you'd need to increase your wall and ceiling splay angles accordingly, to still have a good RFZ around your mix position. I'd also suggest getting rid od most of that glass up front: bad idea. Way too much reflective surface, and it takes up the exact space where you could be soffit mounting your speakers.

Another consideration I am not exactly sure about is floating the floor. How do I do it?

with great care and a LOT of money! :) Seriously, correctly floating a floor isn't that easy, and is expensive. Unless you absolutely determine that you must do it in order to get the isolation you need (calculated from your numbers) then it isn't needed. You say that there is only an empty basement below you, so it sounds like it won't be necessary. The only reason you MIGHT want to consider it is if you figure out that you will have too much flanking through the floor and into the walls.

Or do I even have to do it?

Most likely not!

I do not want any neighbours complaining :) So the Isolation should be fine, right?

That depends on how loud you will be, how quiet the neighbors want you to be, and how much isolation you already have. You need to measure those with a sound level meter, to get real numbers. You can't guess.

I do not know what kind of music will be recorded in it. I guess mostly rock/metal.

Well, that will give you an idea of how loud it might get in there: Assuming acoustic drums, bass amp, etc. you'll be hitting around 115 dB or even more. so now you only have to figure out how quiet the neighbors will want you to be, and/or how quite your municipal regulations require you to be. With those two numbers you can figure out how much total isolation you will need, and after measuring how much you already have, yo can then design your structure to give you the additional isolation that you need to reach your goal. In other words, your very next step is to research the sound levels. You cannot design your isolation until you have accurate numbers. If you try to guess then either you will screw up and not have enough isolation, meaning visits from the police (or from the neighbor, with a baseball bat in his hands!), or (much less likely) you will go too far, install too much isolation that you don't need, and waste lots of money.

I already got rid of the old wood floor, which was loud just walking on it.

So what do you have for a floor now????

Thanks so much for the response! More help than I got out of the books...

Speaking of books, I don't know if you have it already, but if not then I strongly suggest you should get Rod's book: "Home recording studio: Build it like the pros". - Stuart -

jhbrandt wrote:

Honestly, the luxury of slanting walls should be reserved for those that have the space to waste. 1. they do not improve the standing wave distribution but only make them harder to calculate and trap. 2. wasted area (already mentioned) and 3. there are more efficient ways to treat for flutter echo. John

1-3/8 of an inch per 12 inches of wall run is hardly luxury. I think you may want to spend a few weeks and get updated on what John Sayers does here. This generated cavity can be used for absorption in wall. What is your thinking on the "inside out wall"?

Brien, what was the URL of your web page where you have collected all that really useful acoustic information, with all the links to other places? I just lost my bookmarks file (tried to upgrade Thunderbird), and that was one that I really wanted to keep. Could you post it again please? - Stuart -

Yeah, that's the one! Thanks John!!!! :) - Stuart -

Hey there, could not write sooner. There is much going on at the moment.

Grossstadtlegende wrote:

Speaking of books, I don't know if you have it already, but if not then I strongly suggest you should get Rod's book: "Home recording studio: Build it like the pros".

Yes, I have it and I am still reading it. It is a little tough, since I do not know all the german names and some thing are just not available here, like the resilient channel or green glue. A very very informative book though. I had a friend come over to do a precise measurement of the room, dimension wise and I shall have a new plan in a couple of days. The one I had, isnt that great because I did nor have much time doing it. He knows what he is doing though. :) We measured the thickness of the walls and I got and old structural plan of the building, done in 1900. The Walls to the outside are at least 60cm thick and made of bricks. How much reduction does that give me? And I guess this means I might not have to build a second wall? Btw. I was planning on building a wooden frame, fill it with RockWool, and put 2 layers of gipsum board and one mdf on it. I also wanted to decouple the walls from the floor. But since it seems that a floating floor will not be necessary in my case and I am truely relieved to hear that, will decoupling the walls have any effect? By the way, I probably am a really shitty sketchup drawer, but the blue stuff in the original plan was not supposed to be the window :) I wanted to show a friend of mine the gap between the two drywalls separating recording and mixing rooms, because he didn't know what I was talking about. I know that having a 3 meter glass wall would not be that wise :). I was planning on having a 75cm wide window in the middle. Is that still too much? So let me try and summarize. As far as I understand, I do not need to float the floor. I need to change the agles on the mixing room, because the speaker position would be bad.

Soundman2020 wrote:

That is assuming that you will arrange your speakers in the "usual" geometry, being an equilateral triangle with a 60° intercept of the acoustic axis a few inches behind your head

Because, yes I want to set them up that way. I have only nearfields but really nice ones (PMC) :) I should angle the ceiling by about 12°, but first of all I will have to measure the noise levels. The Restrictions in Germany are, max 45db at daytime 35db at night (22-6 o clock). This means if I have a band playing with lets say 115db maybe a little more, I will have to isolate to at least 80db ? Is taht even possible? Thanks again for all the help, and for the cool collection of links!

John Sayers wrote:

http://www.buildthisroom.com/

Mike

Oh I forgot:

Soundman2020 wrote:

So what do you have for a floor now????

I have a concrete floor now.