Hello guys!
First of all, a big thanks to the creator and the participants of this fantastic site!
I am in the midst of constructing a small recording studio, her in Copenhagen, Denmark.
Most of the construction is well underway. Here is a picture of a simple sketchup drawing of the studio:
I am about to construct the isolation room, located behind the small kitchen area, where I plan to record guitar amps, and if at all possible, a drum kit.
Here is a picture:
I have read through the whole reference area, and numerous threads conserning other basement builds, and I feel I have a good understanding of the whole MAM wall building process. I just want to be sure that the construction of this iso-room is as optimal as possible.
The area reserved for this build is about 240cm by 290cm and 250cm in height. The floor is solid concrete with earth underneath. Two of the walls are thick double brick walls, and the other 2 walls are solid concrete with earth outside.
After reading a lot of articles on this site, I have decided not to have a floating floor, but I recently got a hold of some Quiet-glue super cheap, that I intend to use.
My question is this:
Will there be any reason to add rockwool to the existing outer walls, before I build the inner walls? Will I benefit from using 95mm rockwool slaps instead of 70mm? Is around 2 inches between outer and inner wall still the optimal airgap in my case? Is two layers of gypsum for the inner room optimal, or is three layers better? The standard studs for building inner walls here in Denmark are 45mm by 70mm. Will I gain anything by using thicker wood?
My main goal is to let as little noise escape to the apartment above, as possible. I would like to be able to record drums, but I will settle for amp recording if necessary. Room treatment will be done at a later point with some diy-style corner traps, and bass traps.
General comments on my room design will also be appreciated!
Stud walls have been put up in all the rooms, apart from the iso-room and wires have be installed. But I am still considering doing some fancy wall angling, if it will not compromise the general layout of the floorplan.
Amateur recording studio in basement
Originally posted at johnlsayers.com, topic 18658.
Hi " Scamstar", and Welcome! :)
Have you tried plugging those numbers into a room mode calculator, such as this one? http://www.bobgolds.com/Mode/RoomModes.htm The results are not so good. You might want to consider changing one (or more) of those dimensions, to see if you can improve things.The area reserved for this build is about 240cm by 290cm and 250cm in height.
:yahoo: Smart man! :)After reading a lot of articles on this site, I have decided not to have a floating floor,
Yes! Absolutely! It is the damper on the MSM resonance, and all other resonances inside the wall. Leaving that out can cost you around 10 to 15 dB of isolation! :shock:Will there be any reason to add rockwool to the existing outer walls, before I build the inner walls?
Yes, for the same reason: if you can fill the entire cavity, then that would be even better.Will I benefit from using 95mm rockwool slaps instead of 70mm?
The air gap needs to be at least 4". That refers to the distance across the entire cavity, from surface to surface, regardless of the insulation.Is around 2 inches between outer and inner wall still the optimal airgap in my case?
3 layers is always better than 2 layers, but you should do the math to find out if you need it, based on your requirements of how many dB of isolation you need, and what frequencies you need it at.Is two layers of gypsum for the inner room optimal, or is three layers better?
Not really. There is a slight advantage at very low frequencies with more rigid wood, but the effect is not worth the cost.The standard studs for building inner walls here in Denmark are 45mm by 70mm. Will I gain anything by using thicker wood?
You should define that in terms of decibels: How many dB of isolation do you need? Putting objective numbers on it is the smart thing to do. - Stuart -My main goal is to let as little noise escape to the apartment above, as possible.
Thank you so much for the reply!
I'm mainly trying to maximize the area I have, in order to record drums. Furthermore, I'm not really sure how to read the outcome of those room mode calculators :oops:Have you tried plugging those numbers into a room mode calculator, such as this one?
Ok. So does that mean that I can just fill the entire area with insulation, and no air gap at all?. That would be great news, because then I don't have to worry about keeping the insulation from collapsing over time!if you can fill the entire cavity, then that would be even better.
Right. More mass! I guess it will also depend upon what kind of doors I will be able to get my hands on for this build. I guess there will be no reason to go for 5 layers of drywall, if my door solution wont be up to par. I better look up on that, before I even get into this illusive "math" aspect you speak of.3 layers is always better than 2 layers, but you should do the math to find out if you need it, based on your requirements of how many dB of isolation you need, and what frequencies you need it at.
But more rigid wood would benefit me in a drum recording situation, right?Not really. There is a slight advantage at very low frequencies with more rigid wood, but the effect is not worth the cost.
Ok. So the optimal solution would be to bring the sound leakage from the room, down to something like 30-40 dB. My prior research have lead me to believe that a drum set will let out as much as 110 dB. That means that my aim is something like 70-80 dB of isolation. Is that even possible, and if so, will a 4" gap still be optimal?You should define that in terms of decibels: How many dB of isolation do you need? Putting objective numbers on it is the smart thing to do.
To get a basic "go/no go" no decision, it is fairly easy: scroll down until you see the text section, and see if your ratio pass all three BBC tests, and that it is in close to one of the top ten ratios. If that's OK, then scroll down to the bottom and look at the Bonello diagram. If it looks like the example on the left, you are doing great, but if it looks more like the example on the right, then you have problems.I'm not really sure how to read the outcome of those room mode calculators
Right, but do so intelligently! If the maximum area leads to a really bad ratio, then you would be MUCH worse off than a slightly smaller room with a good ratio.... Modal response is a bitch, and will bite you hard if you aren't careful. Imagine if you happen to build a room that cancels all your floor tom sounds at the room mic location due to the modes, and at the same time triples the reverberation of the kick drum...I'm mainly trying to maximize the area I have, in order to record drums.
Yup! Insulation is mostly air anyway, so filling the cavity does not get rid of the air gap. In fact, believe it or not, technically it increases the size of the air gap by a factor of about 1.4! :) (Acoustics is not too intuitive at fist glance.... ) However, do check your fire codes and building code: you might not be allowed to completely fill the cavity...Ok. So does that mean that I can just fill the entire area with insulation, and no air gap at all?.
:shot: :D Yup, there's a LOT of math that goes into designing a successful studio! So sharpen your pencil, and pull out those old high school text books... Or at least fire up Excel on your computer! If you look around the forum, you'll see many examples of great studios that worked out fantastically, because they did the math and paid attention to detail. Then there are quite a few examples of the "other" kind of studio too... :) Those are the threads where you see the builder "going his own way", ignoring advise, and not bothering with math... those are normally the threads that sort of trail off into nothing, and the studio never gets finished, or they never post the final outcome...Right. More mass! I guess it will also depend upon what kind of doors I will be able to get my hands on for this build. I guess there will be no reason to go for 5 layers of drywall, if my door solution wont be up to par. I better look up on that, before I even get into this illusive "math" aspect you speak of.
You won't like this answer, but it's the best I can give you: "That depends." The reason I can't say more than that is because walls are resonant systems: they vibrate and resonate in various ways at different frequencies, and there are four distinct "zones" of the spectrum: The frequency where the division occurs between each of those regions depends on how you build your wall. And the relationship between that and how well your room isolates, depends on the frequency spectrum of the music you are playing inside. So without doing all the math, I really can't say if you'd be better off with stiffer studs, or not.But more rigid wood would benefit me in a drum recording situation, right?
60 is about as much as you can hope for in a typical home build. You could probably it 70 if you have VERY deep pockets and are able to work with high precision in your build. But 50 to 60 is more realistic. - Stuart -That means that my aim is something like 70-80 dB of isolation. Is that even possible, and if so, will a 4" gap still be optimal?