John Sayers' Recording Studio Design Forum Archive

Hi All,

First time in the forums! I've been planning a build at the bottom of my garden, easily 30m from the house, and i was looking for some advice.
I make electronic music mostly, never recording vocals. I'm coming from a 3m x3m bedroom studio which i've outgrown. My budget for this is about £3000. The build is in England.

Pics attached.

I'm looking at doing 5.5m x 3.5m, i have marked this out in wood in the pictures to outline the shape. 2.5m height overall as i believe this is as high as you can go without planning permission.

First things that come to mind that i'd like to know are :

1. Where are windows acceptable? I want as much light in as i can really, i was thinking of a couple of skylights towards the middle and a window on the wall. I won't have windows on the walls where the fence is as its pointless. Can i have a window on the back wall? or the wall i'm facing, or neither?

2. Ceiling type inside? - Flat ceiling ok? Or a vaulted/open ceiling? Any advice here would be great.

3. Where's best to have the door? Does it matter?

4. Thinking of building the studio out of SIPS panels, any thoughts on this? I found a site that will build the shell to your spec then send it you and you assemble it, i was going to link it but didn't want to appear spammy.

5. Overall size/shape - I will work 'long ways' i.e the listening position will be me working towards the short wall (probably looking at the fence end) - Should one of the long sides be a different length to the other? Would splaying the walls help? I thought i read that somewhere.

6. How far should i bring my speakers in from the front wall? I will work in an equilateral triangle with the speakers, but I want to be careful i don't end up sitting halfway between the from and back wall in the middle of the room, as i believe this is a dead/null spot for bass?

Any other help, tips, links, advice is more than welcome!

Just a few Q's, apologies if it's quite a lot. Thank you so much for any help and advice,

Thanks

H there "elastic", and Welcome!

I make electronic music mostly, never recording vocals.

So this is basically just a control room for mixing and mastering? No tracking of live acoustic instruments?

I'm looking at doing 5.5m x 3.5m, i have marked this out in wood in the pictures to outline the shape.

That's a reasonable size for a small project studio. Minimal, but usable.

2.5m height overall as i believe this is as high as you can go without planning permission.

Under "permitted development" rules, yes 2.5m is the limit for the height, if you are within 2m of the property boundary. If you are more than 2m away from the boundary, you can go up to 4.5m if you do a gabled roof, or 3.5m if you do a shed roof. I have designed a few studios for customers in the UK, and that's what I recall from the permitted development documents last time I did it. Hopefully they have not changed! But do get a copy, and check them. So if you could move yours away form the fences to get a 2m margin all around, you could go a lot higher, and open up some much better options for the design.

1. Where are windows acceptable?

Anywhere that they don't get in the way of acoustic treatment! So not in the corners (no doors in the corners either). Usually the middle of the walls is a good choice.

i was thinking of a couple of skylights

Skylights are very hard to isolate, acoustically. Better stick to just windows.

Can i have a window on the back wall? or the wall i'm facing, or neither?

It is possible to have a window on the back wall, but not recommendable. The back wall is always the toughest to treat in a small studio, and is always the source of many problems, so it's best to leave hte entire back wall available for treatment. The middle of the front wall is fine, and the side walls are too.

2. Ceiling type inside? - Flat ceiling ok? Or a vaulted/open ceiling? Any advice here would be great.

Flat ceiling is fine. With only 2.5m max roof height, you don't have space for a vaulted ceiling!

3. Where's best to have the door? Does it matter?

Same rule as for windows: yes it does matter, and NOT in the corners. The middle of the side wall is a good option, or the middle of the front wall. It COULD go in the middle of the back wall as a last resort, but preferably not.

4. Thinking of building the studio out of SIPS panels, any thoughts on this? I found a site that will build the shell to your spec then send it you and you assemble it,

It is possible, but it all depends on how much isolation you need. Isolation requires mass: LOTS of mass, and SIP panels don't have much mass...

5. Overall size/shape - I will work 'long ways' i.e the listening position will be me working towards the short wall (probably looking at the fence end)

Correct!

Should one of the long sides be a different length to the other? I thought i read that somewhere.

No, definitely not. That's a myth. In reality, your control room must be perfectly symmetrical, because you will be mixing in stereo (I assume?). So your ears MUST hear exactly the same acoustic signature, or you will end up skewing the mix one way or the other. It will sound fine in your room, but will sound bad in other rooms.

6. How far should i bring my speakers in from the front wall?

Zero! Nothing! It's a small room, so there is not enough space to get your speakers far enough way from the walls so that you don't have SBIR artifacts. You need sa distance of at least 3m between the speakers and the front wall to force the SBIR issues down to a low enough frequency, and that is physically impossible in a room that is only 5m long. So your only other option is to put them up against the front wall, which pushes the first SBIR dip into the lower mid frequencies, where it can be absorbed with a relative thin porous absorber, such as 10cm of OC703 or similar. So push your speakers right up against the front wall, except for 10cm.

An even better option is to "flush mount" your speakers, sometimes also called "soffit mounting". That's the single best thing you can do to a room to improve the acoustics.

I will work in an equilateral triangle with the speakers,

Forget the famous "equilateral triangle". It is also a myth. Well, OK, it's a myth in that it is the only possible way to set up your speakers: it isn't. It's merely a good starting point, and works for most rooms, but is NOT necessarily the best for any room at all! It is nothing more than a simplified misrepresentation of how it should actually be. That "equilateral triangle" thing is all over the internet, in all types of books, all over YouTube, and every place else you look. But that does not make it correct. It would only be correct under two very specific conditions:

1) If the speakers and your head were set up some place where there is no room around them: out in the open, where there speakers are not "acoustically loaded" by the room, and there are no reflections or reverberant field. And:

2) For all listeners who have had there ears surgically transplanted onto their eyeballs!

Think about it. Every speaker manufacturer will tell you that the absolute flattest, cleanest sound from there speakers is "on axis": when your ear is lined up perfectly with the acoustic axis of the speaker. Yet all of those "equilateral triangle" diagrams show the acoustic axes interesting in the middle of the engineer head, which means that the ears are NOT on axis! They EYES are on axis... So if your ears are in your eyeballs, the equilateral triangle is the correct way to set up your speakers. For the rest of us, the speakers need to be set up so that the acoustic axes are aimed at the ears, not the eyes.

In fact, there are many indications that show that the axes should actually be aimed a bit outboard of the ears, not directly at them, since the head itself affects the sound as it approaches the ears, and also to create a wider sweet spot around the mix position. Thus, acoustic axes from your speakers should intersect at some point several inches behind your head, not in the middle of your head. Usually it turns out that the speakers are aimed at a point about 12 to 18 inches behind your head.

There are good locations for the speakers in the room, and there are bad locations. There are also good locations for the mix position (engineer's ears) in the room, and bad locations. In most rooms, creating the "equilateral triangle" puts the speakers in a bad location, or the head in a bad location, or both. And if yo put them both in good locations, then you no longer have an "equilateral triangle". My answer to that is: "So what?" There's no logical or acoustic reason why the distance between the speaker cones must be identical to the distance between the cone and your ears. Yes, the distance from the left speaker to your left ear must be the same as the distance form the right speaker to your right ear, in order to ensure that the two sounds arrive in phase and at the same intensity: Absolutely. But that has nothing at all to do with the distance between the speakers! In what way does that distance cause the sound to be better or worse? Answer: In no way!

So it's a myth. The truth is that the speakers should be set up at the best point in the room for your speakers in your room, and your head should be set up at the best location for your head in your room, then angled correctly such that the acoustic axes of the speakers intersect several inches behind your head, usually around 12" to 18" back.

But that means they won't be angled at 30° any more! Yup. So what? There is nothing magical about 30°. It just happens to be the angle you need to create an equilateral triangle, but once you abandon that myth, then you are automatically abandoning the need for a 30° angle: Yes, both speakers must be angled exactly the same, so the angles on each side are identical, but it does not have to be 30°. Anywhere from 25° to 35° is just fine, and under certain circumstance you could even go as far as 20° and 45°. Not more than that, though, for other reasons that I don't have time to go into here.

But you don't have to take my word for it: try it out for yourself! In your house, set up your speakers in the classic text-book "equilateral triangle", 2 feet away from the front wall, 1/3 and 2/3 of the room width, angled exactly 30°, with your chair set up so that the axes pierce your eyeballs and intersect in the middle of your head, then carefully listen to your favorite music like that (flat EQ: don't adjust!). Listen to a few songs that you know really well, and pay attention to the bass tightness, accurate definition in the mids, clarity in the highs, as well as the width of the sound-stage, and clarity in the stereo imaging. Move your head side to side, and forwards / backwards, to see how that changes, and how big your "sweet spot" is. The quickly and silently (all sounds turned off, so as not to lose the mental reference of what you just heard) move everything around to set it up the way I outlined above, and listen to the same songs again, at the same volume, once again paying careful attention to all of the above.

Then tell me which setup works best... Which one gives you the best stereo imaging, clearest sound-stage, and broadest sweet-spot, as well as the tightest bass, best definition in the mid range, and clearest, detailed high end?

Don't believe all of the "one size fits all" hype about how so set up your room. All rooms are different. All need different setups. Very seldom does the best setup work out to be a 30° equilateral triangle. Unless your ears are in your eyes!

but I want to be careful i don't end up sitting halfway between the from and back wall in the middle of the room, as i believe this is a dead/null spot for bass?

well..... yes but no. Yes, it's a really bad spot to be in, but no it's not because there will be a bass null there: its because of the modal response of the room. Search the form for "modal response" and "room ratios". All of the first order axial nodes have peaks in the exact center of the room, and all of the second order modes have nulls in the exact center of the room. So that's a BAD place to be. Theoretically, the best place to be us between about 33% and 43% of the room length (front to back), with the supposed optimal spot at 38%. But that is NOT written in stone! It's just a starting point and there's many reasons why you might want to move forward or backward from there.

Just a few Q's, apologies if it's quite a lot. Thank you so much for any help and advice,

Not at all! You are doing fine, and that's exactly what the forum is for: helping out folks who are working through doing their own studio designs, and are need assistance with specifics to keep them on track. (Not like this thread: http://www.johnlsayers.com/phpBB2/viewt ... =2&t=21438 ) . . .

Feel free to carry on asking, and especially when you start putting down your initial design on paper. Or better yet, in SketchUp! Take some time to learn that, and do your design there. But NOT in the web-based disaster that they launched recently! Download the free version "SketchUp Make 2017", while you still can, and use that.


- Stuart -

Wow amazing first reply, thanks! I really appreciate such a detailed reply, im hungry to learn and thirsty for knowledge!

So this is basically just a control room for mixing and mastering? No tracking of live acoustic instruments?

I will be using it as a 'live' room too, in the sense that i will be playing and jamming via drum machines and synths which will be located along the side walls. I will do all my mixing at the front of the room.

Im thinking now i will have a window in front of me where i mix, and a glass door or in the middle of the long side.

Quote:
4. Thinking of building the studio out of SIPS panels, any thoughts on this? I found a site that will build the shell to your spec then send it you and you assemble it,
It is possible, but it all depends on how much isolation you need. Isolation requires mass: LOTS of mass, and SIP panels don't have much mass...

When you say isolation, do you mean soundproofing so neighbours can't hear? Or isolation so the i can not hear outside noise?
I live in a very quiet road with no traffic or anything around, so outside noise is no problem.
In regards to neighbours, I don't work too loud to be honest, i will get a db reading tomorrow as approx the level i work at, but generally i don't have it really loud. I turn it up now and then just to get a feel of what its sounding like loud, but not many times in a session.
We are lucky that we're quite far down the bottom of the garden from the house, the neighbours both sides are both the same, and behind the fence at the back is an old peoples home which is quite far away.
The studio would be approx 25-30m - maybe more, away from the house.

I was thinking on the inside i could make a 20cm cavity wall, i would then pack it with rock wool that is 45kg/m3 density - is that a good idea?
I have made plenty of corner traps and absorption panels from that stuff and i know GIK use that in exact density in their bass traps.

An even better option is to "flush mount" your speakers, sometimes also called "soffit mounting". That's the single best thing you can do to a room to improve the acoustics.

My monitors are Genelec 8040a near field monitors - is it ok to flush mount these in the walls?
If i don't, i would indeed leave them 10cm from the front wall on sand filled stands. How far in from each side should the monitors be if the width across the from was 3.5m?

Thanks!

What are people’s thoughts on building the walls out of hollow bricks? Do you keep them hollow or?

Thanks

Anyone? I'm looking to really keep sound in and heard density was important in the walls. Are breeze blocks acceptable? Anyone who has ideas on what would work to create a good wall and roof would be great.

Thanks

I don't want to waste space here, but I want you to know that I see your question. I just don't have an answer for you bud!

I don't even know what breeze blocks are

Hopefully someone knows.

Greg

Hi elastic,

I don’t know what breeze blocks are either. As far as leaving them hollow, you might need to core fill a few for structural strength, but the rest you could put sand in. Sand would work well due to its damping effect.

If you’re serious about isolation (which goes both ways, outside noise coming in and inside noise getting out) then you should do a 2 leaf system, that is 2 walls that don’t touch. A room inside a room.

That said, your room is on the smaller side as it is and a room inside a room will suck up some of that real estate.

Mark

Breeze block:
A.K.A. Cinder block, besser brick, CMU, concrete masonry unit, hollow concrete block, and several others.

I will be using it as a 'live' room too, in the sense that i will be playing and jamming via drum machines and synths which will be located along the side walls. I will do all my mixing at the front of the room.

So no actual live recording of acoustic instruments using mics: no problem. That's fine. It would only be a problem if you wanted to record using mics.

Im thinking now i will have a window in front of me where i mix, and a glass door or in the middle of the long side

When you say isolation, do you mean soundproofing so neighbours can't hear? Or isolation so the i can not hear outside noise?

I mean "isolation" only, which is the same in both directions! You cannot isolate a wall such that sound can get out easily but cannot get in! Nor vice-versa. If you stop sound going one way, then you stopped it going both ways. Acousticians prefer to not use the word "soundproofing", since it is basically meaningless, and impossible anyway! "Meaningless" because it means very different things to different people, so it's easy to get confused. To one person it means "total isolation, such that no sound gets through at all". To another it means "partial isolation, where some sounds get through". To a third person it has nothing at all to do with isolation, and only ever means "treatment inside to reduce resonance and reverberance". And to yet another it means "treatment in the room to make it sound good". All of those are in direct conflict with each other, none of them are wrong, some of them are impossible, so we don't use the term. By "impossible" I mean that it is a physical impossibility to fully "soundproof" anything, since any sound that is loud enough will absolutely get through any conceivable barrier that Man can build. The loudest sound ever to be recorded on planet earth, was powerful to crack concrete 300 miles away, and totally destroyed everything with a radius of dozens of miles.... so "soundproofing" is an impossible, inaccurate term that people in acoustics tend to avoid.

So we are talking about isolation here, NOT "soundproofing", and isolation means stopping sound getting out, and stopping sound getting in: there is no difference between those, and the same word applies to both.

I live in a very quiet road with no traffic or anything around, so outside noise is no problem.

No wind? Rain? Thunder? Hail? No aircraft ever fly over? No dogs? Cows? People? Neighbors mowing lawns? Paying radios?

In regards to neighbours, I don't work too loud to be honest, i will get a db reading tomorrow as approx the level i work at, but generally i don't have it really loud. I turn it up now and then just to get a feel of what its sounding like loud, but not many times in a session.

Please post your measurements, and make sure you use "C" weighting and "Slow" response.

I was thinking on the inside i could make a 20cm cavity wall, i would then pack it with rock wool that is 45kg/m3 density - is that a good idea?

As long as the two sides of your cavity wall do not touch each other at any point, and are not mechanically connected to each other at any point (except the floor). Not even a single nail, screw, piece of wire, wayward scrap of wood or mortar, nor anything else can be allowed to bridge the gap between the two "leaves" of that wall.

I have made plenty of corner traps and absorption panels from that stuff and i know GIK use that in exact density in their bass traps.

That's fine for bass trapping and for wall cavity damping, but not necessarily for other acoustic needs, such as other types of treatment. Also, that density is ONLY correct for mineral wool: not for fiberglass insulation or other types of insulation. The GFR is different for different materials.

My monitors are Genelec 8040a near field monitors -

Nice!

is it ok to flush mount these in the walls?

Yes. Genelec even makes a flush mount kit for those. You do NOT need to buy that kit, though: It's just one way of doing it. I only mention it to show that the manufacturers themselves approve of flush-mounting for the 8040, and considered it in the design of this speaker. There are very few speakers that cannot be flush mounted.

What are people’s thoughts on building the walls out of hollow bricks? Do you keep them hollow or?

Either way is fine. It depends on what you are trying to do, and the actual wall design. If you are planning to do a single-leaf wall for your studio, then absolutely you WILL need to fill the hollow interior of the bricks with sand, in order to get the mass up as high as possible. This assumes that you do not need high isolation, since it is very difficult to attain with only a single leaf wall. On the other hand, if your breeze block wall is part of a proper fully decoupled two-leaf MSM wall, then there's not so much of an issue: you could leave them empty, as long as you compensate in the other leaf, or you could fill them if you wanted to, in which case you would get better isolation and could reduce the MSM air gap, as well as probably reducing the surface density of the inner-leaf. You have many options.

I'm looking to really keep sound in and heard density was important in the walls.

Yes density is important. For a single-leaf wall, it is crucially important because it defines the entire isolation. For a two-leaf MSM wall it is still important, but not as critical as for a single leaf.

Are breeze blocks acceptable?

Yes.

Anyone who has ideas on what would work to create a good wall and roof would be great.

Look around the forum and search for terms like "fully decoupled 2-leaf MSM isolation" to find out how it works, and what you should be aiming for with your design. Basically, you need the outer-leaf walls AND the outer leaf roof to have similar surface densities, as well as being totally sealed into a completely air-tight "envelope". Then you build your actual control room inside that "envelope" as an entirely separate, independent structure that does not touch the outer leaf at any point. That's all.

For example: Make your outer-leaf as a breeze block wall all around with a beam-and-block roof, then build a stud-framed room inside that (four walls and the ceiling) also as a single leaf. Two doors back to back, one in each leaf. Two windows back to back, one in each leaf. Add your fully isolated HVAC system (yes you do need one), and you are done!

- Stuart -

Thanks Stuart, this has been great reading. May I ask what is a HVAC system?

Thanks

May I ask what is a HVAC system?

HVAC = Heating, Ventilation, and Air Conditioning. It is the system that provides fresh air for your studio (so you can breathe), removes the stale air (so you don't die), as well as heating the air inside if it is too cold, and cooling the air in inside if it is too warm. It also includes controlling the humidity.

Yes you will need an HVAC system. Many first-time studio builders think that they don't need "such luxury", but they do because it isn't luxury. For a studio, it is a basic necessity. Each room is sealed completely air-tight (it has to be, in order to isolate!), and the shell around the entire studio is also sealed air-tight (it has to be, in order to isolate!). So no air can get in or out, unlike a normal house, office, school, shop, church, etc... those are deliberately NOT sealed, so air CAN get in and out. But a studio is different: hermetic, twice over. A studio is also wrapped in thick layers of thermal insulation (it has to be, in order to isolate!), and has a large thermally insulating air-gap around it (it has to be, in order to isolate!). So no heat can get in or out either. Hence, you DO need a proper HVAC system for your studio, and no, "opening the door every now and then" is not an option: that wont work.

You need an HVAC system. And it needs to be properly integrated with the studio, such that it ONLY allows air to get in and out, while stopping sound from getting in and out.


- Stuart -

Sorry if talk of HVAC scared you off elastic!

You will probably find that your £3,500 budget won't get very far in the UK. I got a quote from a brick layer for over £3000 for single skin for the outer leaf for a smaller room than yours.

I went timber frame to do it myself. If you're using breeze blocks (BTW Stuart they aren't breeze blocks you showed in the UK ) see below) you can't go single skin without support piers. Building regs require it and it needs to be vented too.

A mini split aircon unit costs over £1000 to install (Pro installation only by law in the UK). Plus you will spend over £500 on ventilation and silencer boxes. Then £500 or so on diy doors. You will need £500 just to build the concrete base.

That's before you get in an electrician, and before any acoustic treatments (you'll need a £75 microphone for rew to do it properly).

You could build an outbuilding in the UK for maaaybe £3500 but not an isolated studio. I've budgeted £10000 for a studio that size building it DIY. I think I'm just in budget atm (half way through).

I'm not trying to scare you, but I'm trying to help you realise you will need to either save up, or build in stages.

Dan

Breeze blocks are not made these days, but the term is used to refer to either the lightweight aerated concrete blocks, or standard concrete blocks :

Thanks for this Dan, apologies for the late reply. I had to put the build on hold for a few months but I’m back on it now.
You’re totally right re price! I was naïve!

I’m looking at doing a 2 leaf system and was thinking of using SIPS acoustic panels for both leaves - leaving a 10cm gap between the 2 leaves - - anyone tried that or have any thoughts?

I’m not sure of the density of those acoustic sips panels, I work at about 70db average so I wonder if that 2 leaf sips panel idea would be good for neighbours not hearing me working.