My wife and I are in the construction stage of a house with a downstairs soundproof studio. I ambitiously took on the challenge of designing the studio myself mostly as I’ve been really interested in the bizarre nature of sound and enjoying the process of dreaming up a studio. It's a mix room / live room with a vocal booth. I have photos of current construction, diagrams and have made a sketchup model but they currently won't attach properly so I'll try again shortly.
THE GOAL:
The studio will be used almost daily for Drum tuition. For this reason soundproofing will be my priority.
I'm also a producer & DJ, I record bands occasionally, I’ll definitely be recording live drums, various instruments and vocalists for my own projects. I want to treat the room well so I myself and other engineers can do final mixes knowing it will translate well.
CURRENT CONSTRUCTION COMPLETED:
- Concrete Slab Poured – on the earth, the exact size of the studio.
- Brick wall complete on North and West walls.
- The external Stud Frame – All 4 external wall frames are complete, 90mm stud framing. Where the two brick walls are there is sarking between the brick and the studs, this sarking is 50mm from the brick with the stud wall up against it. (it's purely to stop moisture from the bricks).
The inner leaves of the main room and the vocal booth isn't built but will be decoupled completely free standing rooms within this. Insulation will be in the air gap (more on this later).
The external roof will be the above floor, this is completed and tiles and bamboo floor will be laid on it very soon. The Inner roof will be decoupled from this with insulation in the air gap.
There is a stud frame already built between the vocal booth and the main room but it’s getting changed when we build the inner walls. The vocal booth will be decoupled from the main room and accessed through two sliding glass doors.
Window - There is a 12mm laminated V-lam hush glass window on the East wall which opens outwards with a winder and has a strong seal.
It is a window designed for acoustic isolation that we ordered early in the piece in order to get building approval. Since then I’ve noted the need for an inner leaf window which will be a 6mm laminated sliding window with acoustic seal. The air gap between will be approximately 280mm. Basically both windows can open up and allow fresh air in when I’m not making noise, also will be handy if I need to call out to kids in the backyard (Baby no.1 due in 5 weeks!).
The Entrance Door is currently not constructed but the plan is to use 2 solid core doors and the builder is figuring out a frame - it looks like it’ll be a through frame and I plan to buy a good mechanical seal system but it’s not yet in the budget and I need to do more research on an affordable option.
Power is already supplied to the future power points which will be block mounted. I’ve attatched the electrical plan showing current positions. Studio lights will also be hanging mounted lights.
Power has also been supplied for the Air Con unit - I’m planning on a Split system unit (more on that later).
WALL CONSTRUCTION PLAN (outside to inside) :
- Brick Wall (North and East) / Fibre Cement Cladding (West and South).
- Outer Stud Frame (90mm) lined with 2.5 Rock wool bats (90mm) in gaps between studs.
- Gap between stud frames 30mm. (Total air gap from brick to the inner leaf soundcheck boards is 260mm)
- Inner stud frame
- 10mm soundcheck board (laid horizontal)
- Layer of green glue.
- 13mm soundcheck board, (laid vertical)
RW RATING:
Our attempt at calculating this current wall plan is that it should achieve RW70, take 5 off to get RW+c 65 rating (for bass heavy music). Which is 5 better than my goal.. a little buffer zone for being too optomistic.
I need advice on achieving equivilant Isolation with the entrance door (if this is possible). If my door only achieved RW60 would that mean that in reality I’ve wasted money making the walls RW70? Or is it still worth going for RW70 walls either way?
DIMENSIONS OF MAIN ROOM:
Between inner dry wall 6480mm long, 4500 wide, 2440 high
External wall measurements (from outside of brick ) 6980 x 5050 x 2700 (to support beams of floor above)
BUDGET:
The external Structure was costed as a part of our house loan and was on the plans that went to council. This included Concrete Slab, Brick wall, the external stud frame, external window, and external door. I’ve had an allocation of $20000 for the rest of the studio build. This has already been all quoted / allocated and gone over budget by $4000 with the current plan specified in this post! This includes both materials and labour. Because I’ve already gone over budget the treatment inside the studio will have to happen as a DIY 2nd stage when holidays come around. I’m hoping that my current plan is well sufficient so far and that possibly some cost saving ideas and advice my result from this forum of great minds! ☺
LIVE / CONTROL ROOM:
I’ll often record myself playing the drums and various instruments on my own so the live room is also the control room as it provides a quicker work flow for me, also the flexible large space allows me to rehearse and conduct workshops there. As far as the live rooms acoustics go I want to prioritize treating it as a mix room.
I've tried to design it as close to the golden ratios as possible within the limitations of the block. I will hopefully find the budget to include bass traps, broadband absorbent and disbursing treatment to the walls, a cloud to the roof and hopefully building helmholtz resonators (more research required) and also building the speakers into the walls.
VOCAL BOOTH:
The vocal booth began as a storage area but I’ve now upgraded it, it’s a strange shape but I figure I’ll put a bass trap in that narrow corner and use a lot of absorption along with the abstract shapes of drum cases as no-cost diffusers or them covered and a heavy curtain drawn for further absorbtion. Drums are loud enough that I don’t hear my computer in the recordings, meanwhile anything quiet I can record in the vocal booth.
GLASS DOORS TO VOCAL BOOTH:
My plan is to install two glass sliding doors with an air gap in between. They'll be In between the speakers, in line of site from mix position to the vocal booth. The doors I've budgetted for include one 6mm laminate and one 5 mm laminate glass door with good acoustic seals. The seals apparently provide about RW10 extra so they recon it should achieve about RW 45-50 total but I haven't seen exact test results. (Further Question on these doors later in this post)
THE MUSIC : My music will often be bass heavy – Acoustic kick drums, analogue synths and electronic music with plenty of Sub. I like to feel the bass however we don't usually belt the drums and I don't plan on mixing too loud. Loudest Mixing level based on current home studio testing is 86DB average 93 Peak.
LOUDNESS / REDUCTION
Testing levels in my current studio I found that my loud drumming was 96DB peak and average of 91DB so I would predict that inside the studio would get to 100 DB at times. (louder on occasion if recording loud rock bands but lets not get too worried about that as it will be less frequent). I'd like outside to be 40 (not heard by neighbours) so I would like to achieve an overall reduction of 60db if possible.
NEIGHBOURS
The north and east facing walls of the external leaf are brick. These walls face the neighbours, the North wall with the entrance door is only 6 m away from the neighbor!! As shown in the plans the west and south facing walls aren't brick but West faces into the side of the hill. And the south wall is the vocal booth side. Although these two walls face into the side of a hill they do find open-air and neighbours are about 20 metres away. As I teach drums most 5 days a week 3-7:30pm you can see why my main consideration is soundproofing.
SUB WOOFER POSITIONING ISSUE :
Unfortunately I’ve already discovered a design flaw and need advice..
I had forgotten my plan do buy a reference sub to go with my Yamaha HS80 speakers. I DJ and produce music that needs great attention to the sub bass and without it I tend to want to over-compensate in my mixing, I definitely do want do add a sub to my set-up. The problem is that it’s position would naturally be central where my glass doors to the vocal booth are in the way!! I need to decide how to go about this in order to continue with the build. Here are the options I’ve come up with..
Sub Placement Option A :
If I could be sure that my speakers would sound great 3m or more apart and that me sitting 3m or more away from them would allow me an ideal listening position in the room then I could place the sub central. I could place the stationary pane of the glass door central and the sliding door to the left. I could have the sub sitting central with treatment between it and the glass pane. In this situation the glass sliding door would open for access in between the sub and the speakers built into the wall. Good for sub position but limiting my speaker position to be 3m apart. Is this too wide for my room and these speakers? Currently I use these speakers 1.5m apart in my smaller 3.3m wide studio. I’ve read advice to get the satellites as wide as possible but is 3m too wide? Could my stereo image suffer being this wide?
Sub Placement Option B :
I could buy two subs and run them in stereo mounted in under the HS80s either side of the glass sliding door. This way I would be able to place the satellite speakers closer together or wherever sounds best.
The sub I planned to buy is the HS8S which are only about $400 so although it seems a waste of money I could buy two of them. So long as the pair of subs are positioned symmetrically will they stay in phase? Do you face them at the same 60 degree angle as the satellite speakers or straight forward?
I feel like this is a good solution but I need to know if there are problems with using a stereo pair of subs and also if there is a work around for these subs only having a phase switch rather then 180 degree dial..
Sub Placement Option C :
Just so I’ve listed the option.. The sub could go central if it was at my feet. I could buy a speaker processing management unit and time delay the sub so I could have it closer but still in phase. At first this seemed like a good idea but thinking it through the sound would bounce back and reflect off the glass doors and return again. So phasing issues caused by this would probably make this option a really bad idea right?
QUESTIONS IN REGARD TO THE CONSTRUCTION OF MY SOUNDPROOF WALLS:
Q1. How big should my AIR GAP be between the two leaves? How do u calculate this? I know bigger is better especially for bass isolation but how big is appropriate with this design? The gap will have R2.5 Rockwool 90mm batts. The external walls are built but the inner leaf framing isn’t constructed. On my sketchup plan I’ve left a 100mm air gap but got the measurements today from the builder that we will actually have 260mm (from external brick wall to inner sound check board including the isolation thickness and stud frame.) If feel like this is a big gap but would love some conformation.. if it's too big I should save space for the two walls that don't already have a gap between brick and sarking.. (that alone is 50mm). If 260mm is perfect than I'll make sure the gap is that big all around the external walls and to the vocal booth.
Q2. In Regards to my SLIDING DOORS to vocal booth as described in detail above as 5mm laminated glass, 30mm air gap, 6mm glass. It's an extra $450 to get thicker 8mm and 10mm laminate glass doors. Do you think I will need the extra thickness? At the moment my walls between the live room and booth have 12mm soundcheck board green-glued to 10mm soundcheck in each leaf. Is this overkill and a waste of dollars spent on thick soundcheck board when I should spend it on the thicker glass instead? Or even save it for the entrance door?
I've started thinking a better combination could be 8mm laminated glass along side 10mm green-glued to 8mm soundcheck board for the leaf on the live room side, then a 300mm air gap ? Any thoughts?
Q3. I know I need a different material leaf on the vocal booth side. Seeming the vocal booth won't get as loud as the live room I'm thinking I could save some money here by using a cheaper material all the way around the booth's inner leaf, What would be a good alternative to more soundcheck boards?
Q4. For the west and south EXTERNAL WALLS brick isn’t practical so i need an option that would achieve good enough mass to be relatively as soundproof as the brick wall..? My builder suggested having a layer of 9mm FC cladding (Fibre-Cement board that suits external walls). Any thoughts on this?
Q 5. Which is the best INSULLATION? My current plan is to use 1 Layer of 90 mm thick R2.5 Rockwool sunscreen bats which I read has a density of 40kg/m3.
Or should I use semi-rigid fibreglass density 48kg/m3?
Q6 Also is it best to line the gaps of the outer leaf stud frame or the inner leaf stud frame? Practically I think it's going to be easier to line the external frame as they can do that before building the internal frame and get to it easily. Does it make a difference?
Q 7. I looked into AIR CONDITIONING using steel ducts that have been treated with sound installation and the job was roughly priced at $10 000 which I can't afford. I’ve heard that the flexible plastic ducts are cheaper and easier to install but they weren’t offering this.
They reckon a split system won't leak sound through the pipes as the holes cut in the walls are small and the pipes are thick. Split system fits my budget at about $3500 installed. So if this is the case I’ll go a split system.
Fortunately I have easy access to install a ducted system later if business blooms. They also showed me an option of a split system that pulls in fresh air through a hose but they couldn't guarantee that this one wouldn’t leak sound out to the neighborhood.
Fresh air through a simple split system seems like a great find if it doesn’t compromise the sound isolation! Has anyone looked into this? Its called Urura Sarara 7 by Daikin.
I’ll probably go wit the simple standard split system, will this keep the sound from getting in and out well enough?
Thanks for taking the time to check it out - sorry this has ended up massive! I've re-edited a zillion times before posting trying to ask less questions and add more detail.. but this only leads to more questions haha!
Any advice or feedback is deeply appreciated. I will be sure to upload more photoes as we progress.Brad.
but better to have more detail than not enough 
I don't believe they cause any more sound leakage than any other kind of AC as long as they are installed and sealed correctly.
Hnag on, you said two of the walls are already brick: why do you also need a framed wall in addition to that? The outer leaf is only ONE leaf, which is the brick in this case. How come there is also a frame there? Is this maybe a brick veneer house we are talking about, not solid brick?
Bad idea. Any type of operable window is a potential breach of your MSM system. Windows should be non-operable (fixed in place). You might want to screw that in place and seal it extremely well, with acoustic caulk.