Hi!
My husband and I are building a recording studio-plus-shed in our backyard. We don't have a lot of space, and there are a bunch of really irritating restraints due to keeping clearance around sewage assets etc etc. But we're nonetheless very excited. The studio will be a single 5.5mx4m room with standard 2.4 ceilings, with a small potting shed next door. Right now we're in the planning stages.
The floor will be timber boards on a concrete slab (with acoustic foam in between)
The roof will be Colourbond.
There'll be built-in cupboards on the wall separating the shed and the studio.
Window will be double glazed, door will be solid core with a seal.
Music played/recorded in here is mostly folky stuff, so nothing SUPER loud. Probably no drums, at least not a full kit.
We're currently trying to find a balance between:
1. soundproofing quality - the studio is freestanding in a quiet area, but there is a tram (trolley in the US) about 35m away which we can hear in our backyard. It's more of a high squeal, not a low rumble like a train.
2. space (because the studio is so small, having super-thick walls will be a significant loss of precious space).
3. money (we've got about $30,000 to spend, give or take $5k). Some of the work we can do ourselves, but we're not very experienced builders.
Caveat: I know the walls shouldn't be parallel. I know the box shape is basically the worst. But we're very constrained for space (stupid trendy inner suburbs) and money. We have a deal that if my husband's currently semi-pro music turns into a professional business, we'll move to somewhere with a bigger backyard and start again.
So here are the questions:
1. What should we build it from? Double brick? Filled concrete blocks plus plasterboard? Weatherboard (to match our house) plus stud, insulation, 2 layers of plasterboard with green glue in between? Remember we're trying to keep the walls as thin as possible, while getting as much soundproofing as we need (also don't want to go overboard with soundproofing if it isn't necessary). I've looked at a million websites about STC and SRI, but am not sure how to achieve the best result for the thinnest wall-width (at a not ridiculous cost).
2. Would having a well-insulated gabled ceiling be okay for soundproofing? It'd add height to the room, and remove some of the boxiness.
I'm attaching our basic design - the external shape is fixed because we need clearance around a stupid sewage manhole on our neighbour's property, and a property service branch on ours.
We'd be very grateful for any advice!
Small studio from scratch
Originally posted at johnlsayers.com, topic 18483.
Hi "Lilifish", and welcome! :)
Great! That's actually a fairly decent ratio for a studio. It should work out well, from that point of view.The studio will be a single 5.5mx4m room with standard 2.4 ceilings
When you say "timber boards", I assume you mean something like laminate flooring?The floor will be timber boards on a concrete slab (with acoustic foam in between)
That might be a problem: Any time you trap air between two hard, solid, heavy surfaces, you have created a resonant chamber, and it will "ring" at it's own natural resonant frequencies.There'll be built-in cupboards on the wall separating the shed and the studio.
Double-glazing is good for typical street noise, but not so good for typical studio noise: the glass is too thin and the air gap is too small, so the natural MSM resonant frequency is fairly high; that means that isolation for low notes is greatly reduced, even though it blocks higher frequencies OK. You also only mentioned one "door", but in reality you need two of them, back to back, separate by an air space.Window will be double glazed, door will be solid core with a seal.
How loud is that squeal? It would be good to put numbers to all of this (decibels).there is a tram (trolley in the US) about 35m away which we can hear in our backyard. It's more of a high squeal, not a low rumble like a train.
Then don't make them thick! :) Instead, use higher density materials. Isolation ("soundproofing") depends much more on mass than it does on thickness, so use the most dense materials you can afford, since higher density implies the same amount of mass in a a thinner material, or more mass in the the same thickness.2. space (because the studio is so small, having super-thick walls will be a significant loss of precious space).
That sounds reasonable, but to be certain, call up some local contractors and ask for their "flat rate" per square meter for building an outside "granny flat" of 20m2. That's about the same total cost as what you need to do.3. money (we've got about $30,000 to spend, give or take $5k). Some of the work we can do ourselves, but we're not very experienced builders.
They can be parallel, if designed correctly. The problem with parallel walls is "flutter echo", where high frequency sounds sort of "zing" back and forth between the walls. But that can be handled with suitable acoustic treatment on the walls, so it's not a big deal.Caveat: I know the walls shouldn't be parallel.
A rectangular shape is fine: it's square shapes that are bad, and the worst of all is a cube. Also, anything where one dimension is an exact multiple of another dimension, or within about 5% of it. So a room measuring 2.4m x 2.4m x 2.4m is about as bat as you can get, one of 7.2 x 4.8 x 2.4 is almost as bad, but varying that to 6.5 x 4.1 x 2.4 improves things quite a bit. And yours is OK. With rectangular rooms, what's important is the ratio between the three dimensions. If you search the forum for "room ratio" you should find lots of info on this.I know the box shape is basically the worst.
To answer that, you first need to answer the even bigger question: how much isolation do you need? In terms of decibels. Different materials are useful for different scenarios. 20 cm thick reinforced concrete on all sides, for both leaves, is the absolute best, but the price is pretty high. A single layer of 6mm drywall on each side of a 2x3 stud frame is dirt cheap and thin, but hardly isolates at all. So it's a matter of finding a balance between how much isolation you would like, the materials you can afford, and how much space they take up. It all depends on knowing that number: how many decibels of isolation you need.1. What should we build it from?
don't bother with STC ratings: The STC system is a single-number rating for isolation in the SPEACH range: mid frequencies ONLY. It does not consider the lowest frequencies at all. The bottom two and a half octaves of the music spectrum are simply outside the range that STC covers, and therefore a wall that has a a high STC rating might be really bad at isolating drums, bass guitars, and the low end of the keyboards, while a wall with a lower STC rating might do a great job. What is most important is something called "transmission loss", which measures how much energy the wall blocks. It is usually shown as a graph, showing how much is blocked at each frequency. An even easier method is just to talk about isolation in terms of sound pressure levels: the numbers you would see on a simple sound level meter set to "C" weighting and "slow" response, since that's a good representation of the way we perceive loud sounds.I've looked at a million websites about STC
Great! If you got to understanding that point, then you are now a fully qualified studio builder! :) You have the basic parameters correctly identified, and you know that you have to trade them off against each other, so you are ready! This might help: http://archive.nrc-cnrc.gc.ca/obj/irc/d ... /ir761.pdf That's the single best document I'm aware of that compares literally hundreds of different wall types, analyzing each one in an acoustic laboratory, and showing the complete results. It should give you all the info you need to help you figure out that trade-off.am not sure how to achieve the best result for the thinnest wall-width (at a not ridiculous cost).
You can yes. It's a bit harder to build, since the ceiling has to be done to the same level of isolation as the walls, but increasing the height is pretty much always a good thing, for acoustics. You only need to be careful about reflections and "bass build-up" in the angle at the top. But once again, that can be treated.2. Would having a well-insulated gabled ceiling be okay for soundproofing? It'd add height to the room, and remove some of the boxiness.
Two things you probably have not considered but are essential for any studio: HVAC and electrical. You need to get fresh air in, stale air out. You need to cool and dehumidify the room. And you need electrical power and lighting. And you need all of those without compromising the isolation of your room, or the acoustics. All of these need to be considered together, as you design, since they all interact with each other. - Stuart -We'd be very grateful for any advice!