John Sayers' Recording Studio Design Forum Archive

Hi All

Thanks all first to anyone who has contributed to these forums as I've learnt more than i thought i ever would.

I am fortunate enough to be moving into a new house that has a rumpus area which is going to be the new studio.

I've only had one look in person (and didn't take a tapemeasure) as I don't have access to the area at the moment until the purchase period is complete, but would like to ask some preliminary questions while I consider the design stage.

I am hoping to submit a full sketch etc in the future.

I have attached photos from the real estate website.

Location: Hillcrest (south of Brisbane), Queensland, Australia.

USE: The use will be both a control and recording room mixing mainly rock and pop

BUDGET: At the moment not much as we have just bought the house and have pretty much given up the hope of ever getting to eat food again, but in truth I will have enough left over at the end of each pay to work on a little bit at time. I am prepared for his to be an ongoing job

Room: 4.2 Metres x 6 Metres. Given that they are the real estate measurements I would assume this includes to the little outlet/pokey out bit at the end of the room. 2 windows and one Air-Con unit.


QUESTIONS
1. I would like to isolate as much noise going to the neighbour as I would really like the chance to record an amp inside which I previously haven't been able to do. I was thinking of putting a false/freestanding wall along the side with the air-conditioner. The walls I believe, are brick veneer. Would this be considered 2 leaves

Would creating an extra internal wall (maybe ply wood with insulation internally) help at all, or would this be considered a 3rd leaf. Only touching areas will be around the air-con and I would probably put extra insulation over the window.

What if I leave a large air space?

I was also thinking of creating a 3rd wall outside of the house again insulated, completely surrounding the room, really want to be able to record an amp inside which i didn't have the luxuray of where i am now.

Should i bother with these in the design or not?


2. Removing the carpet is not an option. I have read a few posts regarding why this is bad but I couldn't find anything regarding treating a room with carpet. Is there anything to reduce its impact?

3. The small protruding space at the rear I was thinking of possibly turning into either a vocal booth or isolation chamber for a guitar cabinet. What is the smallest space you would recommend for a vocal booth? If not, is there any preferred end of the room for the mixing desk (either facing the protruding space next to it facing away?)

4. Not directly related to the room but in my previous house (much smaller room for mixing), I hung 2 clouds (basically 2 pieces of insulation side by side wrapped in flannel sheets) directly behind my sitting position. My thought was that this would catch early reflections out of the speaker and then absorb more sound bouncing of the back wall. I also used them when recording vocals as my mic was right next to the mixing desk. I haven't seen this anywhere else so was just wondering just how wrong I was in doing this….


Thanks for any responses, hopefully I will have a full sketch up drawing by the end of the year!

JK

1. I would like to isolate as much noise going to the neighbour as I would really like the chance to record an amp inside which I previously haven't been able to do. I was thinking of putting a false/freestanding wall along the side with the air-conditioner. The walls I believe, are brick veneer. Would this be considered 2 leaves

Would creating an extra internal wall (maybe ply wood with insulation internally) help at all, or would this be considered a 3rd leaf. Only touching areas will be around the air-con and I would probably put extra insulation over the window.

In order to isolate very well, you need an inner leaf that does not touch the outer leaf anywhere except the floor. Period. Your outer leaf has to be air tight (sealed with caulk). Your inner leaf also needs to be air tight. Speaking of the air conditioner, you will need to move that to your inner leaf and also install ventilation to bring in 25-30% fresh air through silencer boxes. We don't know your roof/attic details but hopefully you can situate these above the ceiling in the picture?

I was also thinking of creating a 3rd wall outside of the house again insulated, completely surrounding the room, really want to be able to record an amp inside which i didn't have the luxuray of where i am now.

A 3rd wall would for sure make a third leaf. This would make things worse in the lowest frequencies where we strive to achieve isolation. It also would cost way more and honestly, I'm not sure how you'd even go about it. Short answer. No. Don't even think about it.

Should i bother with these in the design or not?

Every detail of the design or build should be included in your SketchUp model.

2. Removing the carpet is not an option. I have read a few posts regarding why this is bad but I couldn't find anything regarding treating a room with carpet. Is there anything to reduce its impact?

Why can't your remove the carpet? You won't achieve great acoustics in your space with carpet. Figure out a way to remove it.

3. The small protruding space at the rear I was thinking of possibly turning into either a vocal booth or isolation chamber for a guitar cabinet. What is the smallest space you would recommend for a vocal booth? If not, is there any preferred end of the room for the mixing desk (either facing the protruding space next to it facing away?)

Can you knock down that wall and make a nice rectangular recording space?

4. Not directly related to the room but in my previous house (much smaller room for mixing), I hung 2 clouds (basically 2 pieces of insulation side by side wrapped in flannel sheets) directly behind my sitting position. My thought was that this would catch early reflections out of the speaker and then absorb more sound bouncing of the back wall. I also used them when recording vocals as my mic was right next to the mixing desk. I haven't seen this anywhere else so was just wondering just how wrong I was in doing this….

Read some more on the forum and check how everyone else is designing their rooms. You need 6"-2' thick of hangers or insulation on the wall behind your head. You need to fire your speakers down the long length of your room. These two things in tandem are critical. Furthermore, you have to decide what style of control room you are wanting. The most popular (and ultimately best) design is an RFZ control room. If you're wanting to mix and record in the space, you're going to have to use variable acoustics and your design is going to be a lot more tricky than individual rooms.

Thanks for any responses, hopefully I will have a full sketch up drawing by the end of the year!

I wouldn't count on having the design complete by then, but I'm sure you'll be well on your way with it! Study a ton more, ask way more questions and start learning SketchUp. We all look forward to your design progress!

Greg

Thanks Greg for the answers.

Much to consider!

Cheers
JK

Hi JK, and Welcome to the forum!

Adding to what Greg said:

The use will be both a control and recording room mixing mainly rock and pop

Those are actually two conflicting acoustic needs. The acoustic response of a control room needs to be very tightly controlled, within certain well-defined specs (see here for an example of how that is done in practice: http://www.johnlsayers.com/phpBB2/viewt ... =2&t=21368 ), but a tracking room has different acoustic needs. It is possible to make variable-acoustic treatment to achieve both goals, but it's not so easy to do.

Room: 4.2 Metres x 6 Metres.

Height? Rooms are 3D, and so is sound. The relationship between the three dimensions of your room can have an effect on the acoustic response. There are "good" ratios and "bad" ratios. You should do a little research on that. It's one of many aspects of room design, but don't get too hung up on it. It is important, but not critical.

I would like to isolate as much noise going to the neighbour as I would really like the chance to record an amp inside

Numbers: You'll need to put some actual numbers to that. There are equations and tables and spreadsheets and rules-of-thumb that you can use to figure out how to build your room (in terms of materials, thicknesses, techniques, etc.) but in order to use those, you first need to know how many decibels of isolation you need. That's the first thing you need to define about your room.

I was thinking of putting a false/freestanding wall along the side with the air-conditioner.

Isolation is "all or nothing". That means that if you don't isolate ALL sides of the room (including ceiling and possibly also the floor, under some conditions), then you won't have any isolation at all!

Think of this: Imagine there's a guy who wants to have an aquarium in his living room, because he likes to look at fish, so he goes to the store and buys a metal frame to make his aquarium. But then he thinks: "I only need to see them from the front, so I'll just buy one sheet of glass to put on that side, and leave the rest open". How well do you think that aquarium will hold water? Obviously, it won't hold water at all! But that is what you would be doing if you only isolate one wall...

In other words, if you do need to isolate your room from anything, then you need to isolate it from everything. You cannot isolate a room in only one direction, just like you cannot build an aquarium with glass on only one side. As soon as you put water in it, the water will simply gush out and splash all over, in ALL directions, even the direction where the glass is, since the water will go over, under, and around that glass. If you only isolate one side of your studio, then when you "pour" sound into it, the sound will gush out and splash all over, in all directions, including the direction where that one isolation wall was, because the sound will go under, over, and around that wall, as if it wasn't even there.

Therefore, if you do need isolation, then you need to build the same amount of isolation in all directions around your room, and in all aspects: every wall, ceiling, door, window, electrical conduit, HVAC duct, and everything else, must all be isolated to the same level. Acoustic isolation is only as good as the weakest point, so if you isolate your studio fantastically all around except for the window, then you might as well not isolate anything, because sound will take the "easy" path out through that window...

The walls I believe, are brick veneer. Would this be considered 2 leaves

Possibly, but it would likely be a coupled two-leaf, since walls built like that usually have metal ties across the cavity. You would have to find out for sure how the walls are built, in detail, to be certain.

Would creating an extra internal wall (maybe ply wood with insulation internally) help at all, or would this be considered a 3rd leaf. Only touching areas will be around the air-con

Then it would be very poor isolation. As Greg mentioned, each leaf must be fully decoupled from the other: no mechanical contact at all. Even a single nail that bridges between leaves is enough to trash the isolation.

I would probably put extra insulation over the window.

Insulation does not isolate. That's a common myth. Insulation does practically nothing to isolate. Mass is what isolates, not air, and insulation is mostly air...

What if I leave a large air space?

Assuming you do build a proper fully-decoupled 2-leaf MSM isolation system, then having a larger air gap drives the resonant frequency down lower, which is good as it basically moves the entire TL curve across to the left, as seen on a typical TL graph. Larger gap = lower frequency = better isolation.

I was also thinking of creating a 3rd wall outside of the house again insulated, completely surrounding the room,

That would be pretty hard to do! You would have to decouple all of the structure that holds the entire room in place: all of the framing, the ceiling, the bricks, .... I'm not even sure how you would go about that: it would be extremely complex, and very expensive. You'd have to figure out how to hold up the roof (or room above) when you cut off the existing studs and framework that is holding it up at present. Probably not really an option...

2. Removing the carpet is not an option.

Then having good acoustic response inside is not an option. Sorry! Take a look at all of the studios on the forum, and all of the pro studios that you seen in magazines, web-sites, videos, etc. How many of those have fully carpeted floors? There's a reason for that...

I have read a few posts regarding why this is bad but I couldn't find anything regarding treating a room with carpet.

There's a reason for that too! You can't find any ways to compensate for carpeting on the floor, because there aren't any. About the only thing you can do is to lay a hard, solid surface on top of the carpet, such as plywood, OSB or MDF, then put new flooring over that, such as laminate flooring.

What is the smallest space you would recommend for a vocal booth?

Big enough to stand in and walk around, comfortably, while still having a mic stand and music stand in there, as well as a chair. 2m x 3m would be a decent size. Smaller than that, and it becomes really hard to treat, and sounds terrible anyway, no matter how you treat it.

is there any preferred end of the room for the mixing desk

For mixing, it is absolutely critical that the room must be symmetrical. In other words, the left half must be a mirror image of the right half. That must be true for at least the front half of the room (from the speakers back to just behind the mix position. clearly, you can't do that if your desk faces the niche, and if it faces the other way, then you have another major problem because the door is in the corner of the room! So you have no place to put your corner treatment, and no place to put your speakers. Your best bet is probably to just wall off that niche and forget about it, then use that end of the room as your front, or do as Greg suggested: remove the other part of that wall, and extend the room into the garage, so it is larger than it is now.

I hung 2 clouds (basically 2 pieces of insulation side by side wrapped in flannel sheets) directly behind my sitting position.

Clouds need to go in FRONT of the mix position, between you and the speakers. The purpose is to damp first-order reflections coming off the ceiling, as well as to deal with possible modal problems in the vertical plane. Clouds behind your head can't do that. It might be useful in some rooms to ALSO have ADDITIONAL clouds back there, but the main cloud needs to go up front, over the region between the desk and the speakers.

My thought was that this would catch early reflections out of the speaker

How would it do that if it is BEHIND your head? The reflections will be coming from a point roughly mid way between your head and the speakers...

and then absorb more sound bouncing of the back wall.

The reflections coming from the rear wall that you need to worry about, wil be in the horizontal plane, not so much the vertical. Besides, in a properly treated room, there are no speculator reflections at all form the rear wall: only a diffuse or scattered sound field, that is about 20 dB below the direct sound, and hopefully delayed by at least 20 ms, if possible.

I also used them when recording vocals as my mic was right next to the mixing desk. I haven't seen this anywhere else so was just wondering just how wrong I was in doing this….

Absorption above you is not much use for vocal recordings. What matters is what is BEHIND you. What the mic is facing towards. That's what matters most, since that is what the mic sees (not what YOU see: that isn't a problem). When you have the mic set up for a typical recording session, take a walk around behind the mic, and take a look along the mic itself, from the far end towards where your mouth will be: what do you see beyond that? What surfaces are out there, in that direction? Not just in a straight line, but in a cone that expands out from the mic, and using the polar pattern diagram for the mic to judge how wide the cone needs to be. Whatever surfaces are inside that cone, need to be treated with absorption mostly, or perhaps diffusion. That's what the mic "sees", so that's where the major treatment is needed. What is above and below or out to the sides is not as important, and what is BEHIND the mic is least important (assuming the mic is cardiod or supercardiod). (This is one of the reasons why those silly little "reflection filter" or "portable sound booth" gadgets don't do anything at all useful: to start with, they are on the WRONG side of the mic!)

hopefully I will have a full sketch up drawing by the end of the year!

You'll probably need longer than that. First you'll need to spend some time studying the basic principles of acoustics, and the basic principles of construction, and the basic principles of studio design, and the basic principles of HVAC, then you can start on the actual 3D model. I would allow six months to a year, until your design is ready to start building. Of course, you can START on the model any time you want! But I doubt that it will be FINISHED before this time next year, realistically.

- Stuart -