John Sayers' Recording Studio Design Forum Archive

Hi Guys, does anyone have a good grounding in sound isolation?

I just need some advice on how to achieve a good amount of isolation without looking too much space. I’m not that bothered about acoustics initially, I can figure out the acoustic treatment after.

The main objective is to play acoustic drums a few times a month, record vocalists without picking up the living room TV and use my guitar amp loud now and then.

I had the opportunity in 2013 to build my own bedroom/studio using heavy plasterboard, resilient channels, green glue, rockwool etc so I know how to do the installation… per se.

The unit is on the ground floor of an old victorian industrial building with concrete floors and thick brick columns.

I’m probable only going to be here for 3 years so I can’t go crazy but It needs to be ‘good enough’.

For the 3 stud walls I’m proposing a sort of double leaf assembly, where you’d take off the inner skin of plasterboard, leave an inch air gap, put up an inner 4”x2”stud frame, put rockwool in, then screw in 2 layers of 12.5mm SoundBloc via hat channels.

For the outside layer of the stud walls I’d leave the single skin of existing plasterboard.

The brick wall being such a funny shape, is tricky but I’d propose to attach one layer of heavy plasterboard using resilient channels. The ceiling would be a 4x2”inch stud frame with rock wool and resilient channels, or clips and hat channels, then a layer of Soundbloc. I’m assuming the existing ceiling is reinforced concrete.

Also. In order to bypass the complication of the white steel girders at the top of both the short stud walls, I was thinking of using 45 degree angled 4x2”s to connect with the ceiling timbers.

I’d uninstall the opening window, and fill the hole with rockwool.

I’m planning on swapping the hollow outer door for a fire door, and installing an inner fire door.

For the floor, I was going to try a floating frame, OSB layer etc but I think I’d create a resonating floor. I’m hoping instead, if I put down down heavy rubber matts that would prevent a bit of transmission though the concrete.

I’d always keep the drums and guitar amps between midday and 9/10pm

Please excuse the mess, I just took down the mezzanine and I haven’t organised a skip yet!

At the maximum points, the room is 4.0 metres high, 4.1m long and 3.4m wide for reference. The materials budget is £2000-2500 I’d say. I’ll hire a plasterboard lift and get some buddies to help me with the construction.

My main issue is working out whether to try to figure out a timber frame for the various right angles of the brick construction which would give better isolation or just rely on one layer of plasterboard with a resilient channel. Flanking from the brick wall in the studio connected to the other rooms in my unit and the neighbours is my my concern here though. Would it negate the work done to the ceiling and stud walls?

If anyone has some experience in this and can give me some constructive advice that would be amazing. Feel free to ask any questions, Thanks! Rob


ps. I'll try to find a way to upload the photos, thanks

Hi, I just wanted to post some pictures so you know what I'm getting at. The quality isn't the best but It's an idea at least. Please let me know your thoughts about the approach for the brick wall.

Thanks a lot, Rob

have you tested to see what isolation exists? cover the windows with some plywood (couple of layers), and test. you'll want to check not only outside but at neighbors. i'd start with a 120db @ 1m PA speaker level testand sweep - LF first, then all freq to ensure you know where any coincident MF and HF may be.

in any case, you'll want your inner room structure to be as decoupled from the exterior and much as possible. one option for the floor is a frame on isolation pads and semi-rigid insulation (e.g. Kinetics Noise RIM), and fill the frame with sand to damp and add mass. the inner room sits on that. windows are all sealed with equiv mass - blocks etc.

first though - assuming you build this hyper-insulated room, where is the air coming from? if it is attenuating sound enough not to hear drums, it's not likely someone will hear you weakly calling out for help as you pass out... split AC will no do it. you'll need proper ventilator fan(s) or ERV/HRV unit to handle this.

Hi Gullfo, that is brilliant advice. I haven't met the neighbours on that side yet but I'm going over now to see about doing a few tests. I think I'll try some sine waves but also get the kick and snare down from the rafters and beat the hell out of them. Not sure if the db meter apps are much use but i'll give that a go for starters.

As for the air or lack of. I was in a similarly treated room before this place with a lower ceiling with no ac just a fan. It was a bit hot when my canadian bass noiseman used to come over to jam but it wasn't too bad to be honest! Cold beer also helps. I think the cold weather makes it just about possible. About the only upside of living here...

I'll do a quick test playing on the bare floor, then chuck some scrap chipboard on something soft and see if it makes any difference.

I checked out the kinetics rim product. Looks pretty tasty


I really wasn't sure if anyone would reply so thanks so much!

Rob

studiosixdigital.com and faberacoustical.com have some really nice iOS Sound Level and Analysis Apps. REW, RodeTest, Smaart, ARTA, for computers.
A music track with steady level may be a lot less stressful/destructive on a speaker system.
Stud and plasterboard, entirely isolated from the building envelope, will probably not benefit any extra from RC or Hats or whatever.

Thanks very much for that Dan! I'll definitely be checking them out. I only had 5 minutes to test yesterday so I played some hard kick and snare, and played bass through an amp, really loud. I just left the neighbours with a phone db app which is obviously a toy, but the snare was coming out as around 90 db, and the bass around 70db. They also said the drums were way louder, or at least more offensive. The snare sound plus its reflections is pretty loud so that makes sense. I'm going to do some more research and ask the guys who have a studio here - "Act Cool records" about what they did and if they have some building skills, then hopefully I can get it rolling in a couple of weeks.

Thanks again!