Smaller than small sound editing facility (postproduction)

Hi everyone, My name is Arthur and I am a new member of this fine and unbelievably helpful forum. I have spent quite some time now reading through as many post as possible, learning the basic principles of studio construction and design, but also getting to know the host and most active members. I will very much appreciate any input in regards to my 'studio' construction and design. I must tell you straight away I am very hesitant to call it a studio and very doubtful about any construction as such to take place in fact. I am a sound designer and sound editor for film and television work. Mostly I deal with low-budget shorts, documentaries and other not-too-overwhelming-productions. What I am trying to say is my requirements are not immensely high and I do not mix full-blown hollywood blockbusters. What I have to my disposal is a single room in a flat (apartment) on a 9th floor of a 11-floor building. The building was erected in the 70s and is made of reinforced concrete. The room is 4400 x 2370 x 2475 mm (LxWxH) /14'5"x7'9"x8'1"/. Now, I understand this size far from decent, but that is what I have for the time being. Although, the flat is mine (not rented), there are some issues... The important fact is that I consider this place to be temporary. By that I mean probably up to 2-3 years. For the time being though I need some space to work in. At present the room is untreated and I cannot work like this. My work usually involves dialogue editing, designing and editing sound effects, preliminary mixing. I do not record anything in this room and rarely work with music. The average sound level generated is probably around 70-75dB(C) and hardly ever reaching 95-100dB(C). I believe the through-the-walls sound isolation is not that bad. I have neighbours above, below and to the left and has never heard them as yet (over a year now). Impact sound gets to my ears sometimes, but this is not a problem. As to the airborne sound, the weakest points are naturally my window and door at the moment. The floor and the ceiling as well as the window and left wall are 15 mm thick, whereas the right and bottom walls are 6 mm thick. At the moment the walls are plastered, painted and covered with wallpaper, the ceiling is plastered and painted, while on the floor there is a carpet on concrete, then laminated flooring on typical white foam underlay. Here is the current layout: Although I still do consider (or did?) building an isolated room within the room, there is more than one strong doubt ruining this beautiful dream. First of, my wife will hardly be happy if I sealed the window. Secondly, I do not want to rip out the existing door frame to mount one that would enable opening the door onto the hall, which as you can guess is not the case at present. Thirdly, just below the window (not in the picture) is a radiator. I do not use it, but it has to be accessible nonetheless as there is a heat meter on it (checked 2-3 times a year by the estate administration). First draft of the inner room: The main question is unsurprising: is there a point to plan sound isolation in this space? I mean naturally room-within-a-room. I do not see a way of building a fully decoupled MSM two-leaf structure with single door, accessible/visible window and radiator. Nevertheless, I am more than willing to do this, if anyone opens my eyes to a possible solution to that. I was also thinking of doing that purely to improve the modal response and create a better ratio of, say, 1:1.2:1.9 (W:H:L !), instead of current 1:1.04:1.86. I do not see any way of tilting the side walls (at least 6 degrees) , due to the asymmetrical position of the door and window. I would be also very grateful for any suggestions for most appropriate treatment for this kind of space. I assume the best place for my desk would be against the window rather than anywhere else. A few more words: 1. I work on a 28" iMac, read big flat reflector. Also, it generates some fan and disk noise, which is fine by me. 2. My near-fields are Mackies HR824. 3. I do not have or need a mixing desk. Will use an iPad wirelessly. It is way more about editing than mixing. 4. I would prefer to keep it under $1000 but can go more if necessary. Take into account building materials may be less expensive where I live than in Australia, UK or USA. Before I start building anything or even seriously drawing anything, I would very much appreciate your input. I do care about your wise words and know I can rely on expertise of many of you. I do apologise if I missed any of your guidelines and did forget to mention any details. Hope this is not the case. I will correct these as soon as you point them out. Thank you kindly,

Hi Arthur, and Welcome! :) A couple of comments on your post:

The floor and the ceiling as well as the window and left wall are 15 mm thick, whereas the right and bottom walls are 6 mm thick.

I think you mean cm, not mm! :shock: 6mm is about 1/4". or about half the thickness of a CD case! :)

Although I still do consider (or did?) building an isolated room within the room, ... The main question is unsurprising: is there a point to plan sound isolation in this space?

From what you say, it sounds like you don't really need much isolation. You are not doing any tracking, only mixing / editing, and you are doing it at low levels, so if that is working out for you, and you don't mind the occasional impact noise or street noise interrupting your sessions, then I don't see the need for all that expense. However, you might want to do some tests with a sound level meter to make sure that you are not violating your city noise regulations. Your current neighbors might be fine with your noise, but future neighbors might not! So it would be good to measure the real levels, to check compliance. That said, there are a few things you can do to improve isolation without going for a full "room-in-a-room": The first thing you can do is to seal everything, the second thing you can do is to seal everything, and the third thing you can do is to seal everything... :) For example, go around the room carefully, checking for tiny cracks around the edges of your walls, ceiling and floor, and seal anything that you even suspect might be a gap, no matter how small. Use caulk for that. The same applies to your windows and doors: Check for gaps, and seal the gaps with weatherstripping, caulk, or something similar. Sealing the door includes the gap underneath! The entire room needs to be sealed airtight. If you do that well, you can increase the isolation considerably. Another option is to replace the glass in your windows with thicker laminate glass, and to replace your door with a heavy solid-core door.

I was also thinking of doing that purely to improve the modal response and create a better ratio of, say, 1:1.2:1.9 (W:H:L !), instead of current 1:1.04:1.86.

Well, your current ratio is not good, so trying to improve that would be a good idea. But you might not need to build an entire room-in-a-room to accomplish that. For example, a hard-backed cloud can help to break up modal issues to a certain extent, and even building a single side wall a few cm in from where it is now would help. You can also use some types of angled treatment on the walls, instead of splaying them.

I assume the best place for my desk would be against the window rather than anywhere else.

Yes, that looks like your best option. Are you planning to soffit mount (flush mount) your speakers, or just put them on stands?

I do apologise if I missed any of your guidelines and did forget to mention any details. Hope this is not the case.

Looks like you covered all your bases pretty well! :) In short, to me it looks like you have a usable room that needs some work and lots of treatment, like any small room, but you don't seem to need additional isolation, so construction should be fairly simple. - Stuart -

Thank you for a warm welcome and your prompt response Stuart!

I think you mean cm, not mm! 6mm is about 1/4". or about half the thickness of a CD case!

Yes, naturally :) 150 and 60 mm respectively. Sorry for that.

(...) you might want to do some tests with a sound level meter to make sure that you are not violating your city noise regulations

I will do that.

(...) your current ratio is not good, so trying to improve that would be a good idea. (...) a hard-backed cloud can help to break up modal issues to a certain extent, and even building a single side wall a few cm in from where it is now would help.

I will try to come up with some ideas on this subject and, if I may, I will come back with a drawing or SketchUp project for consultation. I hope you will be able to have a look at that and provide some feedback. For the time being thank you again and I will get back with more concrete details soon,

if I may, I will come back with a drawing or SketchUp project for consultation. I hope you will be able to have a look at that and provide some feedback.

That's what we're here for! :) - Stuart -

I am coming back with a few question I am afraid :D Turn out things look even darker in terms the available space. What I have to do is to squeeze a wardrobe (closet) in there. This has to be at least 550 mm (<21") deep and about 1 m (39") long. Once again, here is the current layout, albeit a bit more detailed: Because of this piece of furniture (this will be made by me, so the dimensions are flexible), I assumed that placing the closet against the back wall (by the door) would create substantial asymmetry. Thus, I came up with something like this: This way I will have even more storage an symmetrical layout. Does this make any sense? I mean, is it a good idea taking into account requirements (storage) and acoustics. I understand that high and mid frequencies will be exposed to more symmetrical layout, whereas the lows will most likely ignore the thin OSB wall and get through it. However, since they are not directional, it does not really matter. What matters is the even reverb time across the whole spectrum I guess, but that is to be measured and addressed at a later stage I suppose. I will most likely install two superchunks against the new walls, such as this: and later on, taking into account the measurements (waiting for the mike atm), it will probably be more or less this: Please advice me in this. Is it a good idea or should I just ignore the symmetry and place the closet against the back wall, next to the door. If not, should the walls be thicker? Is this a good place for superchunks? Here is the sketchup: Thanks a lot in advance, Arthur

I would greatly appreciate your input on this one.

Hi Arthur, Oops! Didn't notice your update! Lots going on...

I assumed that placing the closet against the back wall (by the door) would create substantial asymmetry. Thus, I came up with something like this:

Looks good, yes. Symmetry at the back of the room isn't as critical as at the front, but it's still nice to have if you can. Plan on treating the forward-facing surfaces of that closet with absorption, so it doesn't need to be neatly varnished/painted.

What matters is the even reverb time across the whole spectrum I guess, but that is to be measured and addressed at a later stage I suppose.

Well, technically, it isn't reverb in a small room. You need a path length of about seven times the frequency in order to talk about reverb, so small rooms don't have a statistically valid reverberant field in the lows, or the mids, and it doesn't matter for the highs. But what small rooms DO have, is modal issues. Room modes are easy to confuse with reverb, because they kind of sound like the same thing, but they aren't. Modes are standing waves, defined by room dimensions. The idea is to choose your room dimensions so that your modes are spread out as evenly as possible, without having several all bunched up together, nor large gaps between them. That's hard to do in small rooms. The smaller, the harder!

I will most likely install two superchunks against the new walls, such as this:

Yup! That will help. All modes terminate in room corners, so putting superchunks in corners is a good way to damp them. But that's only two corners: rectangular rooms have 12 corners, so see if you can try to cover at least a few more. Once again, hard to do in a small room. But once again, the smaller the room is, the more bass trapping it needs!

and later on, taking into account the measurements (waiting for the mike atm), it will probably be more or less this:

Also looks good. It seems like you have the right approach. Once again, symmetry at the back isn't critical, so you can pretty much do what you want with the closet there, but the way you have it looks pretty good to me. - Stuart -

Quote:

What matters is the even reverb time across the whole spectrum I guess, but that is to be measured and addressed at a later stage I suppose.

Well, technically, it isn't reverb in a small room(...)

I do apologize. I know that is the case, nevertheless I still tend to forget about it :) Thank you kindly Stuart. That sounds to me like a green light for my initial DIYs. I will post some pictures of the progress. Especially the superchunks or any other treatment I make.