A Bedroom transformed into a small Studio in Sofia(Bulgaria)

Good evening everybody :) I bet I am the first forum member from Sofia, Bulgaria. If so, I am really proud to join this community and represent my small country :yahoo: Let me thank you sincerely and from all my heart for hosting such a great place and for taking time to help all in need. I have been following the forum for years, reading as much as I can and tracking all the useful information you provide. I am an architect. I have also been playing guitar for the last 25 years or more :) In the University we had a band... now, it's just for pleasure and to record some stuff. If anybody's interested, here are some of our recent recordings with a colleague of mine, living in Budapest (Hungary). Marvelous and very talented pianist. https://soundcloud.com/brother-vader 10 years ago, after some really hard work, we had our new family house completed. Today, my daughter is already 21, she is a student abroad, and I am happy to have an empty bedroom :) After some bargaining with my wife, and a couple of sacrifices from my side... voilà, I have a "green light"to transform the bedroom to a small studio. 1) So, let me start with the current situation. Here is the plan drawing: And here is a cross-section of the room: As you will notice, we have pretty massive construction around. I was in the insulation business for years, doing also some acoustics from time to time, so mineral wools are all over the place. 2) What is my target? Separating the room in two: recording booth (vocals / electric and acoustic guitar), and a small control room. As you might notice the room has a big window (pain in the **s), but I have to live with that somehow. Also, all furniture comes from adjacent bedroom, where my small studio is right now, so dimensions are fixed... On the back wall I will have to place an existing bookshelf, full of books. Should be a pretty good absorber anyway: The booth construction is based on Mr.Sayers' drawings, so I would not go in detail in the insulation layers. With regards to insulation, my target is to have decent sound levels in the rest of the house and not to annoy my wife. With close to 600mm. of insulation between me and my neighbor downstairs, I am not so worried about him getting irritated :) Above the room is our living room, then comes the roof of the house with another layer of 250mm. of mineral wool. So no danger of sound penetration in that direction as well. After reading both Gervais and Newell books, I have also tried to check at least all pinned topics in the relevant forum folders. Here is the two initial designs I came to. 2.1) Design 1: Or a Sketchup version: 2.2) Design 2: And the Sketchup version: Here are both Sketchup files: http://dox.bg/files/dw?a=80eb15ee15 As you would see, I am just "marking"the positions of the new walls and absorption layers and elements. I am still not quite sure if I am on the right track and would very much appreciate if you could advise and correct any mistakes. What has made things worse is Mr.Newell and his book. Basically, on pages 272-274 he declares that rectangular shapes are OK, and angling of walls is nothing more than "waste of space", as anyway low frequencies are impossible to reflect. He mentions geometrically parallel walls have nothing to do with "acoustically" parallel ones :) Basically, his idea (if I got it right) is that angling of walls is important only in rooms with poor treatment. So, I came up with Design 2... Please, kindly have a look and help me find my piece of mind :) When I fix the initial design I would appreciate some advise on the correct absorbers and their situating as well. I do not want to make a too "heavy" post (being my first one). In case any questions appear, I will gladly answer all of them. Thank you very much in advance, Cheers, Yavor

I feel it is time to say... BUMP :) Anyone willing to help a poor lost soul? :horse:

Well, obviously there's concerns about the overall small size of the space. It's going to be tough in that scenario... still, assuming that there's no choice about that, here's my comments: Design 1: I'm not a fan. The asymmetry is going to be an issue, with a wall coming so close on the right side, and the wall expanding away on the left side. Design 2: This is definitely an improvement, at least with what you've got for a framework. There's still some obvious concerns, but some of them are unavoidable with this space. Rectangular shapes are often good, square ones aren't. I can't see your measurements clearly, so I'm not sure what the dimensions are, but it's looking awefully like you're sitting in the center of a square.. not good. Question... I know this is undesireable in some respects, and it's not something most people do... but have you considered simply turning the entire room into a control room, and then build a free standing recording booth in the back of the room? The sight lines would be absolutely horrible, but I'm assuming you're just trying to be able to lay down tracks, not run a business. Last suggestion, I'm a big fan of side facing control rooms... I dunno why, but I've liked them best when I've been in studios... Granted one of the studios that was front facing that I worked in, was one of those who totally misunderstand some of the principles of good acoustic design, and just basically carpeted plywood walls as their idea of absorption. If you really want that "studio look" that comes from not having an Iso booth, but a more full construction booth, have you thought of doing something like this? http://johnlsayers.com/Stuff/Small_Studio.skp Side facing control room. Try to keep John's proportions as you put it into your space... I haven't done the measurements, but does this give you enough space for an Iso room?

Hi Johhnie, Thanks a lot for posting ! I suppose you meant something like that: Yes, I was also thinking for such a possibility, as that is probably the only placing where the window (reflective surface) would be OK; However, could not find a place for bass traps in the corners, but probably I have to work a bit more on that... seems quite worth it :) I have rejected the possibility of using the whole room as a single space for several reasons: - it is newly repainted, massive oak floor... would be a waste; - pretty nasty and probably costly details around the window, the radiator.... etc. - I really would like a separate recording booth; Yes, the dimensions of the control room would be in that case (and actually in any case) very close to a square (297 x 270 cm.). Very valuable hint, thanks a lot again! Cheers, Yavor

OK Guys, Here comes the last development: Some Sketchup views: I am still not sure whether to make bass traps on corners of wall and ceiling, or stick to simple false ceiling on all area and bass trap only above seating place / wall-to-wall corners. Will decide on the run. Planned materials: - Walls (from exterior to interior): 50mm.ISOVER FDPL (25kg/m3) in studs / 3x1.25mm.g.board. / ECOPHON Super G 40mm. fixed with Omega profile; - Floor (booth): 50mm. ROCKWOOL (150kg/m3) / chipboard / 50x50mm. wood studs w.ISOVER DOMO (13kg/m3) inbetween / 3x1.25 g.board / BITUVER FONAS deadsheet / 2xchipboard / 20mm.oak floor.; - Ceiling (booth): same as wall; - Ceiling (room): perforated g.board (if basstraps are made) / or whole ceiling with ECOPHON Focus A; Bass traps: broadband absorbers as shown in the forum with 80mm. ISOVER FDPL, some of them on wheels, movable (the ones by the window and in front of the front door); Booth window: 2 pcs. laminated glass, 10 and 8 mm. New Behringer ECM 8000 mic purchased, REW downloaded... and old SPL meter from my previous job found in a cupboard... That's all. Wish me luck. It was more a monologue than a dialogue (hoped to be different and to get a bit more opinions). Johhnie's one was a precious one though, and it counts for ten. Thanks Johhnie ! U are my man :)

In case anybody cares (which I seriously doubt however :) ), here is how the construction goes: http://forum.muzikant.org/topic/145607- ... r-dummies-на-живо-от-софия-и-варна/page-3#entry817412

Hi Yavor Andreev!! How is it going??? :D I'm not an expert but i try to help you, you must understand that the "big" here are pretty busy (they help us for free if they can) and your thread lacks some informations (rules :twisted: ) first of all sorry for my english, let's go: 1-you say that angled walls are useless because of the bass frequencies, i think that these frequencies are not the only one in a room. In a very small room you don't have space for these angled sides and for this reason i think that your design is right! Anyway, especially in a small room a lot of bass trapping is required and because the waves are so big the more the better! :mrgreen: 2

On the back wall I will have to place an existing bookshelf, full of books. Should be a pretty good absorber anyway:

No, it can be a diffuser but this isn't a good thing in a small room (for what i read everywhere) 3

With regards to insulation, my target is to have decent sound levels in the rest of the house and not to annoy my wife. With close to 600mm. of insulation between me and my neighbor downstairs, I am not so worried about him getting irritated :) Above the room is our living room, then comes the roof of the house with another layer of 250mm. of mineral wool. So no danger of sound penetration in that direction as well.

Insulation ad isolation are two really different things: if i understand, you're not building a "MSM" system, so if everything is connected the sound will go everywhere, not matter how much massive your walls are (unless they are REALLY MASSIVE, scientifically speaking 8 feet per wall or more!!!!!!) More mass in only one wall will not increase the trasmission loss of your room because sound "explodes" everywhere also in a tiny hole, and you have a window! Insulation inside the room helps you with the sound of your studio but without a properly builded "MSM" system it isn't enough to stop 110 decibel of Justin Bieber irritating your neighbours!!! :mrgreen: :horse: From the pictures seems like you want to build your vocal booth with MSM...but i'm not sure, from the pictures seems also that you are building a floating floor and a window in the wrong way, other things too! 4 Where is this room exactly??? Basement? 1st floor? Do you need a floating floor? 5 What is your goal in terms of trasmission loss? How many db? Do you play loud??? 6 You need simmetry in sound and placement! In your design you want yourself in the right place inside the room! I/we/THEY :mrgreen: need a lot of informations to help you figure out what is best for you and your room, read the rules!! Anyway i'm whit Johnnie, 1 room and tracking with headphones just because the control room is much more workable if more big. Sorry for my english and sorry if i misunderstood your design, post here on the forum so we can understand your progesses because not everybody understand your mother tongue! :D Bye!!!

Hi Finck :) Thanks for posting ! 1) Bass trapping will be at every possible corner, I agree with that :) No other chance with room so small. 2) Phew, the bookshelf for sure is a diffuser... I was sleeping while writing that. Anyway, behind it will be an absorbing layer. Good or bad, it is there and I have to accommodate it in the room somehow :) 3) Well, it is a MSM system indeed (the booth). I do not care for sound insulating the mixing room, only the booth. I will definitely not play my guitar at 110 dB :) A 60 dBA insulation should satisfy me generally speaking (for the booth) and I think it is pretty achievable (check the pic attached, and that is with 1 layer of GB per side. I will have three + deadsheet). Massive layers bellow the room do make the difference (in my opinion). I really missed to point out that the room is on the 3rd floor of a 4 floors house (my floors are 3 and 4). So having >600mm mineral wool and >200mm concrete between me and my cousin on the 2nd floor.... helps a bit :) 4) I am almost sure the floating floor and the window should be OK, since I took the layers and details from Philip Newell's and Rod Gervais' books. I see no real chance for a "room inside a room" construction without a floating floor. Actually, at the end I will have two FF. You might notice that the room itself has one :) 5) I was thinking a lot on the option of one room / no separated booth. But! Nasty details around window and heater (hot water one, cannot be easily detached), a brand new oak floor to the waste, finally, much more complicated and costly. And again, this is a house, apart from the fellow under me, neighbors are at least 25-30 mtrs. away... Anyway, construction is on the way, I have opened another topic in the "Constructions"forum. Wish me luck and thanks for caring :) Cheers, Yavor

Ok, with that kind of walls for the booth, if builded carefully you should accomplish your goal! Thanks for posting!

Keep rockin' :yahoo:

Hi Yavor, and welcome! Just a few comments on your initial post:

With close to 600mm. of insulation between me and my neighbor downstairs, I am not so worried about him getting irritated

Actually, insulation does not isolate very well. That's a common myth. Insulation is great as part of an isolation system, but by itself it does not do much. Insulation by itself is very good for room treatment, but that's a very different thing. Isolating a room acoustically is one thing, and treating a room acoustically is another thing. To isolate a room using only insulation, you would have to make the insulation about 4.5 meters thick, and it would have to be a 100% perfect absorber at all frequencies from 20 Hz to 20 kHz. There is no such material. So 60 cm of insulation will help a bit with reducing the transmission of high frequencies, but won't do much at all for lows. Your neighbor will still hear all the low frequencies, and most of the mids as well.

On the back wall I will have to place an existing bookshelf, full of books. Should be a pretty good absorber anyway:

It will be much more of a diffuser than an absorber! It will diffuse mids and highs, and scatter some of the low mids, but it won't absorb much.

Here is the two initial designs I came to

#2 is better, but there is a bog problem with both of them: your room is not symmetrical. It is critical that the front half of the room must be perfectly symmetrical (the left half must be a mirror-image of the right half).

he declares that rectangular shapes are OK, and angling of walls is nothing more than "waste of space"

That's for his concept of room design, which I believe he calls NER. For those of us who follow the RFZ design principle, angling the front walls is a critical part of that. There are several different design philosophies, and those are just two of them. So it depends on which philosophy you plan to follow for your room.

as anyway low frequencies are impossible to reflect.

Well, I wouldn't agree with that: A concrete wall 18" thick does a pretty good job of reflecting low frequencies. I'd agree that it is harder to reflect low frequencies than it is to reflect highs, but not impossible.

is that angling of walls is important only in rooms with poor treatment

Once again, that's for his design philosophy, which might not be applicable to other design philosophies.

I suppose you meant something like that:

Yes! That's a better design from the symmetry point of view, and you could even angle your walls slightly, to make better use of space in both rooms: you don't need as much space at the front of the room, where the speakers are, so narrowing that down means you can make the booth wider at that end, which is a good idea. However, there's a major problem with that layout: the bookshelves will have to go. You cannot have one side of the room completely diffusive and the other side completely reflective. Remember, the room must be acoustically symmetrical: both sides exactly the same.

I am still not sure whether to make bass traps on corners of wall and ceiling

Yes, definitely! Your bass traps MUST be in the corners, from floor to ceiling, and you will need to make them very large, since it is a small room.

- Floor (booth): 50mm. ROCKWOOL (150kg/m3) / chipboard / 50x50mm. wood studs w.ISOVER DOMO (13kg/m3) inbetween / 3x1.25 g.board / BITUVER FONAS deadsheet / 2xchipboard / 20mm.oak floor.;

What is the existing floor made of? You probably do not need to do that in your booth.

- Ceiling (room): perforated g.board (if basstraps are made) / or whole ceiling with ECOPHON Focus A;

Make your ceiling fully absorptive. I would suggest 10cm of OC-703 over the entire surface, except where you have the bass traps in the corners, of course.

Massive layers bellow the room do make the difference (in my opinion).

According to mass law, you will get a 6 dB increase in isolation if you DOUBLE the mass of your existing floor. 6 dB is hardly noticeable. If you double the mass again (total of four times the existing mass) then you get an increase of 12 dB. Still not a lot, but that's a huge amount of mass you have down there! But that is not what you are proposing: you said "- Floor (booth): 50mm. ROCKWOOL (150kg/m3) / chipboard / 50x50mm. wood studs w.ISOVER DOMO (13kg/m3) inbetween / 3x1.25 g.board / BITUVER FONAS deadsheet / 2xchipboard / 20mm.oak floor.;" That is NOT a massive floor: it is a RESONANT floor, since it is mass OVER AN AIR GAP. What you have there basically is a drum: a membrane stretched over an air cavity. It will act exactly like a drum, resonating at certain frequencies. Even worse, in your case you are proposing to build TWO different air cavities with two different membranes, so you will actually have a 3-leaf resonant system, which has two sets of resonances! You might want to read this: viewtopic.php?f=2&t=8173

So having >600mm mineral wool and >200mm concrete between me and my cousin on the 2nd floor.... helps a bit

The 200mm of concrete DOES help.... but adding thin, lightweight membranes (chipboard, gypsum board, etc), above it over an air cavity does NOT help much: it can improve high frequency isolation, but it can also make low frequency isolation worse than it was with just the 200mm of concrete, because you are creating a resonant system.

I am almost sure the floating floor and the window should be OK,

And I'm almost sure you didn't do the math to calculate it correctly! What is the resonant frequency? What is the resilience of your floor? How much deflection do you need on your resilient springs to obtain that resonance? How much mass do you need on the springs to obtain that deflection? How much mass do you have? Rod and others provide the principles for floating a floor in their books, but you still have to do the math and work through the equations for YOUR specific floor, in order to ensure that you get it right. Once again, I'd suggest that you read this thread: viewtopic.php?f=2&t=8173

I see no real chance for a "room inside a room" construction without a floating floor

Why not? If the floor already has enough mass and damping, then all you need to do is to build the walls and ceiling! Many, many people have built "room-in-a-room" studios that way, WITHOUT floating their floors, very successfully, with excellent isolation (and they did the math first, to find out if it would work). Then there are quite a few people here on the forum who tried to float their floors like you are proposing, and later on discovered that it was not working, or that it had made things even worse: they then had to decide if they wanted to rip out the floor again, or just live with the problems...

Actually, at the end I will have two FF. You might notice that the room itself has one

Yup, I did notice that, which is why I mentioned that you have an even WORSE problem, since you have a three-leaf system, and a three-leaf system will ALWAYS give you WORSE isolation in low frequencies, as compared to a two-leaf system, or even a one leaf system, of equivalent mass and overall thickness. So by making that 3-leaf "floated", you would have two different sets of resonant frequencies (technically: f- and f+), and they would BOTH be much higher than the equivalent resonant frequency for a two-leaf floor ("f0"), so the floor would isolate worse. Acoustics is a science, and there are equations for calculating these things. It's not about what you "believe" might work: it is about what you calculated. Science works despite what you think about it! :) Curiously enough, you even show an image that very clearly demonstrates the exact issue I am talking about: You show a four-leaf wall on the left with STC-40, then a 3-leaf wall in the middle with STC-50, then a 2-leaf wall on the right with STC-57. Your own image proves, conclusively, that a 2-leaf system provides BETTER isolation than a 3-leaf or a 4-leaf, yet you designed your floor as a 4-leaf???? :shock: :!: :) - Stuart -

Hey Man! Sorry to be AFK for a bit. I'm definitely in agreement with Soundman's concerns re: the number of leaves. Yes, the overall shape is basically the lines of was thinking on, but with some minor refinements. One of the biggest is for the control room to have symmetry on both sides of the listening position. The listening position would need to be centered to the hard boundaries of the room and not to the bookshelf. I'd also give the bookshelf the heave-ho, as it's going to be acting like a diffuser on just one side. It'd interfere with that nice symmetry. Also, can door be adjusted to give yourself more room to treat corners? edit... LOL. I just gave soundmans post a more thorough read, and saw he mentioned both those as well as other things. Sorry, didn't mean to repeat. :roll:

Hi Guys and thanks for all the comments ! Bit late with my reply, was a pretty rough end of the year. Please check out the "Construction" thread :) Merry Christmas and Happy New Year to all of you ! Best regards from sunny Sofia :)