SOUND ON SOUND

[RobGlockenspiel]

I'm the process of turning a loft space into a solo music den. i'm on a tight budget but i want to make sure its as good as can be.

At this stage of the build i have some questions regarding the shape of the room, acoustics etc.

details: Height - 83"
Width - 98"
(longest point) Length - 627"
(Shortest point) Length - 462"

The loft has a pitched roof and because of the width I've decided to place my rear ported speakers along the shortest wall towards the exit (left) and storage area (right). There are going to be 3 windows. the roof joist will be insulated as per regulations and covered with plasterboard. The whole room is timber frame, insulation, plasterboard, plaster. The floor is insulated then 20mm chipboard tongue and groove, there will be laminate flooring too.















Questions:

1. the pitched walls are symmetrical, would angling the plasterboard slightly on one side be beneficial ?

2. What problems will i incur adding this much desk space and how can i deal with it, should i mount anything to the top of the desks ?

3. The speaker wall is solid brick, the cavity between here and the outside wall isn't insulated so there will be a layer of Celotec and then plasterboard. should i put anything else behind the plasterboard or deal with all acoustic issues once the room is completed?

4. Is there anything else i can do (on a budget) to make this room behave better before its all finished/put together ? or should i just get it all finished and deal with any issues afterwards with DIY broadband and bass traps ?

I have been researching these topics and there are lots of similar articles, i will be calibrating my Yam Hs8's as best i can with the controls, running eq wizard and creating my own broadband and bass traps further down the line but if there is anything i can do now to make it better i'd like to know.

i'm firing this out there to see what i can learn from you guys directly. if there is anything else that i haven't mentioned that you think would help i'd like to know :thumbup:

Apologies for the questionable room schematic and for repeating myself. :lol:

Edited to make image links point to the images themselves rather than the imgur page - JP

[Eddy Deegan]

Hi Rob, and welcome to the forum :)

I've just seen this post, and may have more specific input to offer once I've digested it. I'm in the middle of building a studio in my converted loft and at first read your situation looks similar to mine in a few ways.

My thread on it is here. I'm about to start putting together an additional update post to it but if you read through some of the processes/research I've been undertaking then you may get some food for thought on various aspects of your project.

Are you concerned about noise leaking through the brick wall (is it a party wall or does it have nothing of concern on the other side?), from your studio space to the floor beneath, only considering the acoustics in the space itself, or a combination of these things?

[Luke W]

Welcome :thumbup:

Another member of the loft studio club here, although mine was a case of fitting out a space that was already converted. It's definitely worth you having a look through Eddy's thread that he's linked to, there will be lots of information in there that's relevant to your project.

I do have some thoughts to add to a couple of your points, although as usual I'll point out that I'm not an expert in acoustics...

1. the pitched walls are symmetrical, would angling the plasterboard slightly on one side be beneficial ?

I don't think that'd be worth the effort personally, my approach would probably be to keep them symmetrical and then treat the resulting surfaces with some panels at the appropriate points. That way any panels you make up for treatment will be the same either side, and symmetry is going to be your friend when it comes to stereo imaging.

2. What problems will i incur adding this much desk space and how can i deal with it, should i mount anything to the top of the desks ?

If you have a hard surface for the desktops (which desks usually are, of course!) then you'll get some reflections from them, but it's whether or not those reflections make it back to your ears (or how long it takes them to do so) that's your issue, and there's plenty you can do to help there. If the side desks start behind your listening position then that's a good start, and some strategically placed broadband panels would likely be enough to sort any problems that crop up.

[Eddy Deegan]

3. The speaker wall is solid brick, the cavity between here and the outside wall isn't insulated so there will be a layer of Celotec and then plasterboard. should i put anything else behind the plasterboard or deal with all acoustic issues once the room is completed?

Celotex has very good thermal properties but is all but useless for anything acoustic. If possible, I would look into using Rockwool RW3 (the dense 60Kg/m3 stuff). It's relatively cheap, has the consistency of bread and as such is easy to cut with a breadknife, has excellent acoustic dampening properties and is thermally efficient.

However, you will need a thicker layer of it than the equivalent celotex. I've used it throughout the entire studio space in my conversion (floor, walls and ceilings).

Looking at your rafter depths I'm assuming you were considering 50mm celotex? You will need an air gap of about 50mm between the insulation and the inside of the roof itself to avoid condensation buildup. In my case I thickened the rafters by 50mm using 2-by-2 screwed directly onto them and installed 100mm rockwool RW3 with a 50mm airgap above it.

You should definitely check the building regulations for a habitable room as on my project they were clear that 100mm of RW3 (or 50mm of celotex; I use it in the eaves, outside the acoustic space) wasn't enough insulation, so I had to add a layer of multifoil insulation as well.

4. Is there anything else i can do (on a budget) to make this room behave better before its all finished/put together ? or should i just get it all finished and deal with any issues afterwards with DIY broadband and bass traps ?

If soundproofing isn't a concern (both incoming and outgoing) then you'll probably be able to get most what you need from treatment after construction. However, rather than using normal plasterboard I would recommend using acoustic plasterboard if you aren't already. It's thicker and heavier than normal plasterboard but will provide more sound deadening.

Ideally two layers of it, with an acoustic insert in between them, but on a budget even going for a single layer of 15mm+ acoustic board will be better (and not significantly more expensive) than standard plasterboard.

One thing I did which you could consider is to build a 100mm stud wall, insulated with 100mm RW3, right up against the brick wall. As well as providing additional insulation and sound deadening it gives you a nicer internal surface to work on going forwards and on a wall that size it shouldn't break the bank.

[RobGlockenspiel]

Welcome :thumbup:

Another member of the loft studio club here, although mine was a case of fitting out a space that was already converted. It's definitely worth you having a look through Eddy's thread that he's linked to, there will be lots of information in there that's relevant to your project.

I do have some thoughts to add to a couple of your points, although as usual I'll point out that I'm not an expert in acoustics...

1. the pitched walls are symmetrical, would angling the plasterboard slightly on one side be beneficial ?

I don't think that'd be worth the effort personally, my approach would probably be to keep them symmetrical and then treat the resulting surfaces with some panels at the appropriate points. That way any panels you make up for treatment will be the same either side, and symmetry is going to be your friend when it comes to stereo imaging.

2. What problems will i incur adding this much desk space and how can i deal with it, should i mount anything to the top of the desks ?

If you have a hard surface for the desktops (which desks usually are, of course!) then you'll get some reflections from them, but it's whether or not those reflections make it back to your ears (or how long it takes them to do so) that's your issue, and there's plenty you can do to help there. If the side desks start behind your listening position then that's a good start, and some strategically placed broadband panels would likely be enough to sort any problems that crop up.

Hi Luke,

Acoustics is something that is going to take me a long time to get my head around, i'd say my ears are pretty well trained now but i'm no expert either, i lack the terminology needed to identify the problems i hear regarding acoustics and this is something i'm working on moving forward. I've found myself to be questioning the way i do things a lot more with production/recording also, the past 8 years I've just been winging it. :headbang:

These are excellent points Luke, thank you for your time.

[RobGlockenspiel]

3. The speaker wall is solid brick, the cavity between here and the outside wall isn't insulated so there will be a layer of Celotec and then plasterboard. should i put anything else behind the plasterboard or deal with all acoustic issues once the room is completed?

Celotex has very good thermal properties but is all but useless for anything acoustic. If possible, I would look into using Rockwool RW3 (the dense 60Kg/m3 stuff). It's relatively cheap, has the consistency of bread and as such is easy to cut with a breadknife, has excellent acoustic dampening properties and is thermally efficient.

However, you will need a thicker layer of it than the equivalent celotex. I've used it throughout the entire studio space in my conversion (floor, walls and ceilings).

Looking at your rafter depths I'm assuming you were considering 50mm celotex? You will need an air gap of about 50mm between the insulation and the inside of the roof itself to avoid condensation buildup. In my case I thickened the rafters by 50mm using 2-by-2 screwed directly onto them and installed 100mm rockwool RW3 with a 50mm airgap above it.

You should definitely check the building regulations for a habitable room as on my project they were clear that 100mm of RW3 (or 50mm of celotex; I use it in the eaves, outside the acoustic space) wasn't enough insulation, so I had to add a layer of multifoil insulation as well.

4. Is there anything else i can do (on a budget) to make this room behave better before its all finished/put together ? or should i just get it all finished and deal with any issues afterwards with DIY broadband and bass traps ?

If soundproofing isn't a concern (both incoming and outgoing) then you'll probably be able to get most what you need from treatment after construction. However, rather than using normal plasterboard I would recommend using acoustic plasterboard if you aren't already. It's thicker and heavier than normal plasterboard but will provide more sound deadening.

Ideally two layers of it, with an acoustic insert in between them, but on a budget even going for a single layer of 15mm+ acoustic board will be better (and not significantly more expensive) than standard plasterboard.

One thing I did which you could consider is to build a 100mm stud wall, insulated with 100mm RW3, right up against the brick wall. As well as providing additional insulation and sound deadening it gives you a nicer internal surface to work on going forwards and on a wall that size it shouldn't break the bank.

Hi Eddy,

I managed to have a quick scan through your build post this morning, great stuff! I especially enjoyed reading about the floor joist finds, would love to see some photographs :thumbup: I clocked that you where using RW3, I'm surprised at how relatively cheap it is. I was under the impression it was going to cost me a fortune to treat the room, there is a lot further you can go mind but this is a good compromise. Managed to order some off a local guy, going to pick it up tomorrow morning.

The rafters are 100mm thick, the building regs in my area recommend 25mm air gap and 75mm insulation. This is quite an unusual house, built like a tank. The floor joists are way bigger than they need to be. a lot of the internal walls are very thick too. Unfortunately a lot of the plasterboard is already in and its too late to swap it. I'm happy though, this will be a fine music den. Any problems that arise ill deal with it, or put up with it. :lol:
PS: The Gable end wall is insulated in the cavity.

The RW3 stud wall is a great idea, I will have some RW3 left over so ill see how far I can get with it. this can always be done at a later date so thanks for the tip. i may have some questions further down the line but this has been most helpful!

Thanks for the advice Eddy. :thumbup:

[Sam Spoons]

I'd echo the others and say keep it simple. The full ins and outs of acoustic treatment are for experts but basic principle will get you 90% of the way there (at least above about 250Hz). set you mix position somewhere that is not a exact division of the room length, hang broad band absorbers* at the mirror points (on the walls and ceiling where, if you placed a mirror, you would see the reflection of the speakers), keep the mixing environment symmetrical and the fit as many bass traps, as large as is practical to wall/ceiling, wall/floor junctions (maybe fill the unusable part of the room between the pitched ceiling and the floor as deep as possible in your case). You can't have enough bass trapping in a small room.

You'll never get a small room sounding perfect but covering about 30% or a little more of reflective surfaces with absorbers will make a huge difference. The shape of your room will work to your advantage as there shouldn't be any flutter echoes between floor and ceiling and the angled walls/ceilings.

* 50mm Rockwool RW3 spaced 40-50mm off the surface is a good compromise. I posted a sketch in another thread but can't find it so here it is again (not to scale)...