Small Studio Design, Any Changes Before I Start

Hi everybody, Been reading this forum for over a year but this is my first post. I'm ready to build a studio in my spare room with control room and iso booth just want all you experts to check through my design. My Goal- Build a iso booth and control room, were I can record most instruments from vocals to drums (it'll be a tight to fit drums in but I think they will fit). How Loud- won't be recording drums that much and no neighbours near by so main focus is having the booth isolated enough not to hear noise from outside. Budget- £1500 on materials all work done by me or free work by others. Info- Room is 2.36m wide, 4.32m long and 2.35m high, this is inside dimensions (Small I know). Window is 1.6m high and 1.30m wide in the middle of the front wall. Door is 1.2m from the wall with the window on. All walls are made of concrete blocks. Plan. My plan is to build a room inside the existing room with a 2 inch air gap, built of timber frame filled with 60kg insulation, with 1 panel of acoustic plaster board on the back and 2 panels on the front with a resilient bar channel between the timber frame and both panels of plaster board on the front. The celling will be built in the same way and I will be building a floating floor. The booth should be around 2.2m wide and 2.1m long (I know its kinda square and thats not good but I don't know how I can get round that) and should be 2.25m high with an angled celling. I will also be building two panel absorbers and two slot absorber. Heres some pics of my design Here is a SketchUp of my empty room. If anyone has any ideas let me know Thanks Joe :D

Some more pics.

Hi, I'm liking the design. Not liking the budget. And your not going to be building a floating floor! Are you on the 2nd floor or a slab? Would you consider sliding glass doors?

Hi lilith, Thanks for the reply, I did think about sliding glass doors as it would give me a lot more space, but I already have two double glazed panes of glass the size I have draw on the design and two heavy duty fire doors which I never paid for (left over windows and doors from my dads house) so be a waste not to use them. I'm on the first floor, which is built on solid concrete then chipboard floor, underlay then laminate wood flooring. was going to put a layer chipboard on top of that with really dense foam (or neoprene) underneath to decouple the room from the floor. (good idea, bad idea?) My budget is a bit on the cheap side But I have worked out my material cost and should cost a lot less I get 55% off insulation so i'm paying around £290 for all the acoustic plasterboard, 60 KG insulation, resilient bar etc... timber and chipboard floor cost came to £179 (excluding slot absorbers and panel absorbers) Thanks Joe :D

You shouldt float your floor if you're on a concrete slab. Your floor is too massive and is already dampened by the earth to resonate and transfer vibrations (or sound) to the walls or adjacent rooms. That will save you a lot of money. Just build your inner walls on top of your floor and you'll safe. I did that and isolation is excelent

Hi jbassino, If I said I would only have to buy laminate flooring for the floor (as I already have foam and chipboard floor) do you think floating the floor on this would be worth doing? If not I guess it would save me on height in my room. (and a bit of money) I know this is the wrong part of the forum but has anyone got any info about the slot absorbers do I just work out the axial room modes and treat them or tangential and oblique? Also with my slot absorber which is covering one of my walls (if you see pic your get what i'm on about) is it ok to put acoustic plasterboard on the wall then build the slot resonator off of that or would I have to put some kind of absorbent material behind the wooden slats. With the smaller panel i'm just going to build the same as my panel absorbers using rockwool or similar. Thanks again Joe

I see several issues with your plan. First, as you already noted, the rooms are nearly square. Even worse, they are nearly cubes! That's bad! In addition, all the walls are parallel. Cubed and parallel is not good. You'll have major room mode issues, combined with flutter echos at related frequencies. I'd suggest you do whatever you can to get away from square and parallel. I would try to angle the dividing wall between the two rooms, and move at least one other wall a bit to get as far away from square as you can. Maybe angle the ceiling as well.

My plan is to build a room inside the existing room with a 2 inch air gap,

Two inches isn't really enough. It should be 4" in order to keep the MSM resonant frequency down low. However, that number refers to the distance between the surfaces of the inner and outer leaves, not to the distance between the new frame and the existing wall. So you could have a 1" gap between the existing wall and the new frame, plus the depth of the studs. That would give you more than 4" of air gap. so if you are taking about a 2" gap between the existing wall and the new frame, you could actually reduce that gap a bit, down to 1", and gain space inside the room, if you want to! Of course, if you don't need the extra space in the room, then keep that 2" gap, by all means! It will help your isolation.

built of timber frame filled with 60kg insulation,

You don't really need such a high density. Normal recommendation here is 48 kg/m3: The higher density won't do anything additional acoustically, and will only cost you more money.

with 1 panel of acoustic plaster board on the back and 2 panels on the front

Forget the acoustic plaster board, and just go with the plain old ordinary plasterboard (drywall, gypsum board, sheetrock, etc.). The acoustic stuff doesn't stuff doesn't do a lot extra for you, and just costs more money.

with a resilient bar channel between the timber frame and both panels of plaster board on the front.

You don't need the resilient channel since you will already have a decoupled stud frame. At least, I assume that by "built of timber frame" and "2 inch air gap" you are referring to a decoupled stud frame? By "decoupled" I mean that the new frame is totally free-standing, NOT attached to the existing walls or ceiling ANYWHERE. No mechanical connection at all (no nails, bolts, screws, wires, blocking, etc.) It can only be bolted to the existing floor, but cannot touch any other wall or the ceiling. If that is what you have, then you do NOT need the resilient channel (RC), since your wall is already decoupled. The RC will cost you extra money, take up extra space, and will not do anything for you acoustically.

The celling will be built in the same way and I will be building a floating floor.

Like others already said, you don't need a floating floor, and you most certainly don't have the budget for it! A proper floating floor would cost many times your entire budget, and is really hard to get right anyway.

I'm on the first floor, which is built on solid concrete then chipboard floor, underlay then laminate wood flooring. was going to put a layer chipboard on top of that with really dense foam (or neoprene) underneath to decouple the room from the floor. (good idea, bad idea?)

doesn't sound like a good plan for the floor, as others already said. I think what I'd do is to take off everything everything that is already on the floor, right down to bare concrete, and just use that as the floor. Concrete is a good floor, acoustically, provided that you go with a soft ceiling. It will also gain you maximum possible room height, which you are short of right now. If you hate the idea of a concrete floor, then just level the concrete with self-leveling cement, and lay laminate flooring directly on top of that.

(as I already have foam and chipboard floor) do you think floating the floor on this would be worth doing?

Nope. Floating your floor is a huge expense, and doing it right is not easy. Do it wrong and you screw up the isolation. You'd be much better with plain concrete floor, and a drum riser (like Lilith's) for isolating drums, amps, etc.

I know this is the wrong part of the forum but has anyone got any info about the slot absorbers do I just work out the axial room modes and treat them or tangential and oblique?

No need to. Just build John's standard slot resonator, which is a broad-band design, and the dimensions are already figured out for you.

is it ok to put acoustic plasterboard on the wall then build the slot resonator off of that or would I have to put some kind of absorbent material behind the wooden slats.

Look at the designs that John has posted here in several places, and that has been built in many studios, successfully. It works very well. Just build it like that, apying attention to all the details. - Stuart -

Hi Stuart, Thanks for the great reply Theres going to be changes to plan thanks to your detailed reply, I'm going to have an 1" air gap as it will give me an overall depth of around 5" with timber frame and plasterboard. (and maybe resilient bar as I have some but don't know if it would improve isolation enough to make it worth having a slightly smaller room). Also going to angle the dividing wall, Angle the celling, and build angled slot absorbers like johns designs on the walls of the booth. (hopefully that will be enough I don't think I can make the room much smaller or less square). Going to rip up laminate flooring and build straight onto the existing floor which is concrete then cement (not just concrete if that makes any difference) going to put strips of foam rubber on the bottoms of the new timber frame walls between the wood and the floor. I have most materials ready to start such as insulation, timber frame, acoustic plaster board etc... So might get started ripping the floor up tomorrow :mrgreen:

Hi everyone Started building, should I start a post in the construction section of the forum? I've built all the walls up just need to build the slot resonators, doors and the window etc... (building everything from the designs in the recording manual on John's website so should all work :) ). Changes to the design from what I posted above are no floating floor and an angled celling and an angled wall between the two rooms. Thanks for all the help so far Joe