John Sayers' Recording Studio Design Forum Archive

hey guys,
I'm very happy I have found you and this magnificent board!
My name is Marcus, and I do almost all kind of things regarding audio: electronic music, recording bands, sounddesign and mixing for films and TV, narration, foley...

I'm quite excited right now, as I can use the space in the pic to build a studio. It is a basement, with the outer walls being massive (40-48cm) with soil around.
I can build walls/doors in that green area whereever I want. the dashed lines are current plasterboard / drywalls. I can remove or use them. the thin solid lines are also plasterboard/drywalls, I can double them if I want. I'm sorry I haven't inlcuded height of the room yet, I will measure tomorrow. its appr. 2,70-3m.

neighbours are not a problem, only towards the entrance, that wall would have to be doubled (or maybe we insert a double entrance door). Also towards the thin solid lines I don't have to care about noise.
I don't mix that loud, film/TV stuff at 79dbSPL, music only shortterm with that levels.

I thought of standard LEDE. Its going to be a mixing room, but also editing, and occasionaly instrument and voice recording. So I'd use the mixing sweetspot for solo instruments / voice rec., which worked fine for me in the past. I think I wont be using subs, just my Neumann 310's.
in addition to the studio room there has to be a smaller rehearsel room, so I cant use the whole green space, but maybe 2/3.
So, right now I plan the building process which will happen hopefully end of summer.
I have around 2000€ I could put into building the room (exl. the ac). another 500€ will go into DIY aborbers and diffusers (if I get somebody to help me plan and execute I'm more than happy to pay somebody)


- what would be the ideal arrangement / position for the walls to get the best sweetspot for mixing?

- would you suggest plasterboard / drywalls or cinder / ytong walls?

- as there are no windows, there is a ventilation system (ac, blue, up left), which carries some noise to the neighbours. Until now, we played drums in the next room, which was devided just by a single drywall, without a problem. If the new studio will be in one room with the ac, we probably have to upgrade it with stronger noisefilters. Any tips what to read here about db limits, prices, possibilities of those ventilation noise filters?


I'm looking forward alot to what you think!

best,
Marcus

sorry if something was too vague or somehow not suiting, is this the wrong place for my topic?

Hi Marcus, and Welcome!

Sorry about the delay! Lots of activity on the forum right now, and only me answering questions....

the outer walls being massive (40-48cm)

Massive what? Massive stone? Massive concrete? Massive brick? Massive hollow cinderblock?

I haven't inlcuded height of the room yet, I will measure tomorrow. its appr. 2,70-3m.

Did you measure that yet?

neighbours are not a problem, only towards the entrance, that wall would have to be doubled (or maybe we insert a double entrance door).

It's a rather commonly held belief that you can "soundproof" a room by building one wall better than the others. In reality, you can't. All of the walls need to be built to the same level, as do the ceiling, windows, doors, HVAC and electrical systems.

I don't mix that loud, film/TV stuff at 79dbSPL

WHen you say "79 dB SPL", are you talking about A weighted or C weighted? What genre of music? There's a big difference between measuring 79 dBC for a female solo acapella balladist, and 79 dBA for a heavy metal rock band. And both of those readings would be terribly wrong.

I thought of standard LEDE.

Standard LEDE was a concept from the 70's that has long since been abandoned by studio designers. It was found to be too fatiguing for long sessions, and not natural at all. More modern extensions of LEDE, such as RFZ, CID, NER and other similar things have replaced LEDE, long ago. I'd suggest that you use a more up-to-date concept for your studio design, not one that failed 30 years ago.

Its going to be a mixing room, but also editing, and occasionaly instrument and voice recording.

So primarily a control room, with neutral, flat, acoustics? But you also want to record things that need live, warm acoustics?

So I'd use the mixing sweetspot for solo instruments / voice rec.,

I'm not sure why you would want to do that at the sweet spot. The term "sweet spot" refers to the performance of the speakers, and the area where their sound fields interact to create, clean, perfectly balanced sound, with accurate stereo imaging, and a clean, precise sound-stage. If the speakers are turned off (as they would be for tracking vocals or instruments) then there is no sweet spot! It's an effect created by the speakers, in conjunction with the room, but without the speakers, there is no sweet spot! There's not really any advantage to recording at the location where the sweet spot would be if the speakers were on. That location would only be acoustically better if the room wasn't very well designed.

I think I wont be using subs, just my Neumann 310's.

Nice! I'm assuming you mean the KH-310 A? You probably won't need a sub with those, but you could if you wanted to. Especially if the genre you normally mix has a lot of deep bass content, then it might be an idea to add a sub. But if it is mostly just vocals and acoustic guitar, for example, then you don't need one.

- what would be the ideal arrangement / position for the walls to get the best sweetspot for mixing?

The room alone does not create the sweet spot. It is a combination of the room and the speakers. The room should be designed with the speakers in mind, such that the work together. Sometimes you see speaker manufacturers advertise that their product creates a fantastic sweet spot, but that's just marketing hype. If you put great speakers in a terrible room, there won't be any sweet spot at all! And if you put mediocre speakers in a great room, you can get a reasonably decent sweet spot. But if you put great speakers in a great room, designed especially for those speakers, then you can have a fantastic sweet spot. Such as in this case:

http://www.johnlsayers.com/phpBB2/viewt ... =2&t=20471

The sweet spot in that room is broad and clean, with excellent stereo imaging, a wide, pristine sound-stage, and absolutely neutral acoustics.

So, to answer your question: The room should be as large as possible, perfectly symmetrical, and meet the specifications in ITU BS.1116-3 as closely as possible, with the relationship between the dimensions being close to one of the known good ratios. The room concept should be RFZ, with soffit mounted speakers, and the mix position set up at the appropriate location. Then the treatment should be designed to neutralize the acoustic problems as much as possible.

- would you suggest plasterboard / drywalls or cinder / ytong walls?

That depends on your isolation needs, and your budget. If you need very high isolation, then high density cinder block, brick, or concrete walls might be necessary. But for a typical home studio, drywall is probably more realistic. Especially on a very, very tight budget, such as yours.

- as there are no windows, there is a ventilation system

Excellent! That's good news.

If the new studio will be in one room with the ac, we probably have to upgrade it with stronger noisefilters. Any tips what to read here about db limits, prices, possibilities of those ventilation noise filters?

What you need there is something called "silencer boxes" or also called "baffle boxes" sometimes. They look like this:

http://www.johnlsayers.com/phpBB2/viewt ... 0&start=45
http://www.johnlsayers.com/phpBB2/viewt ... 9&start=74
http://www.johnlsayers.com/phpBB2/viewt ... 25&start=2
http://www.johnlsayers.com/phpBB2/viewt ... 42&start=5
http://www.johnlsayers.com/phpBB2/viewt ... 61&start=0
http://www.johnlsayers.com/phpBB2/viewt ... 5&start=98
http://www.johnlsayers.com/phpBB2/viewt ... &start=157
http://www.johnlsayers.com/phpBB2/viewt ... =2&t=13821
http://www.johnlsayers.com/phpBB2/viewt ... 8&start=44
http://www.johnlsayers.com/phpBB2/viewt ... 2&start=16


They need to be designed along with the rest of the room, to provide the right amount of air a the right speed while still blocking the right amount of sound.

Regarding your actual original question, that's a very complicate shaped area that you have! There's no clear layout that would allow you to create a symmetrical area simply, without wasting space. Probably your best bet is something like one of these:
None of those is good, as they all create a small room and waste a lot of space around the angled walls. But you could use that wasted space for your HVAC silencers, or maybe a very small storage closet.

- Stuart -

Thank you Stuart for responding so detailed!

the outer walls being massive (40-48cm) - Massive what? Massive stone? Massive concrete? Massive brick? Massive hollow cinderblock?

To be honest, I don't know. They do not noticably resonate. But I know that the top, right, and bottom (not in the pic) walls are towards earth/soil, and the left one is towards a yard and only 24cm thick. But for many years bands were rehearsing in those rooms, so it is really not much of an issue.

I haven't inlcuded height of the room yet, I will measure tomorrow. its appr. 2,70-3m. - Did you measure that yet?

yes, it is 2.55m.

Also, quite good news, I can remove the "old lift", as it is allready closed at ceiling level.

I thought of standard LEDE. - Standard LEDE was a concept from the 70's that has long since been abandoned by studio designers. It was found to be too fatiguing for long sessions, and not natural at all. More modern extensions of LEDE, such as RFZ, CID, NER and other similar things have replaced LEDE, long ago. I'd suggest that you use a more up-to-date concept for your studio design, not one that failed 30 years ago.

Thank you so much for that insight. I am reading now everything I can find on the net on that. Same goes for most of the other things you are telling me, to that I do not respond directly. very useful!

I guess it is going to be some kind of RFZ room. In my last rooms I used something like that without knowing. I always used to put bass absorbers (floor-to-ceiling 60x60cm chunks of rockwool) in all 4 corners, 1x1m basotect absorber on the direct "mirrorsurfaces" between me and the speakers (sides and ceiling), and general diffusion all over the room, until I had very little ERs, but some live sound. I somehow started to call that spot the sweetspot, because I was able to mix, but also to make pretty decent vocal and solo instrument recordings in that spot. I know, wrong terminology, sorry for the confusion, and thanks for the explanation

Its going to be a mixing room, but also editing, and occasionaly instrument and voice recording. - So primarily a control room, with neutral, flat, acoustics? But you also want to record things that need live, warm acoustics?

Yes, a control room! recording is really just for fun and I dont need live, warm acoustics. If I want to expand in that regard I will treat some of the other rooms in the floor.

I think I wont be using subs, just my Neumann 310's. - Nice! I'm assuming you mean the KH-310 A? You probably won't need a sub with those, but you could if you wanted to. Especially if the genre you normally mix has a lot of deep bass content, then it might be an idea to add a sub. But if it is mostly just vocals and acoustic guitar, for example, then you don't need one.

Yes, the KH-310A. Actually, I am working alot on EDM and other bass intense music, but I never really missed alot. Maybe in this room I will miss a bit, as it will be a bit bigger than previous rooms, but I read alot about having 2 subs would be way better than 1, and I haven't got the money for 2 neumann subs, MAYBE for 1.

The room concept should be RFZ, with soffit mounted speakers,

On the Neumann page it says the KH310A are not supported for flush mounting, propably because of the amp / cooling fins? Do you think it would be possible anyway? (do you mean the same with "soffit"?)

If you need very high isolation, then high density cinder block, brick, or concrete walls might be necessary.

just in terms of sound - wouldn't the Ytong / cinder stones be better, as they are more "static"?

Regarding your actual original question, that's a very complicate shaped area that you have! There's no clear layout that would allow you to create a symmetrical area simply, without wasting space.

I do not understand your suggestions for a rectangular room-in-room. Wouldnt it be better to use the existing outer walls and build it like in the attached picture?


Again, thanks for all the other info I did not thank for yet in the quotes!

On the Neumann page it says the KH310A are not supported for flush mounting,

... and yet, this is what the manual says:


Take a look at this thread: http://www.johnlsayers.com/phpBB2/viewt ... =2&t=20471 Those speakers are not supposed to be soffit mounted either... they have huge bass reflex ports on the rear. And yet, after chatting with their chief engineer, and getting a couple of pointers from him (great guy), the results are what you see....

Do you think it would be possible anyway?

I just finished designing a room for a customer in the UK, who will be using the KH310-A's... soffit mounted.

(do you mean the same with "soffit"?)

Unfortunately, "soffit mounting" has become pretty much the industry standard term, even though it is technically not correct. "Flush mounting" is the more correct term, but less used. But they both mean the same thing.

just in terms of sound - wouldn't the Ytong / cinder stones be better, as they are more "static"?

I'm not sure what you mean by "static".

I do not understand your suggestions for a rectangular room-in-room.

Because in general that's what gives you the best isolation at the lowest cost, for the best use of space, and best acoustics. The three options I gave you were the best options based on what you said in your original post. But you did not mention that you could get rid of the elevator, which changes things quite a bit. That's why the forum rules ask that you include everything in your initial post, to avoid making suggestions that might not actually fit well. You also did not mention that it was possible to eliminate the door and passage at the lower right of your drawing. Since that wall was NOT marked as a dotted line, and since you said that ONLY the walls on the dotted lines could be changed, I did not attempt any layouts that would violate that. You originally said that you could only "double" those walls indicated with solid lines, but the implication was that they could not be moved. Based on all of this new info that was not in your original post, it now looks like a non-rectangular room might make better use of the available space.

However, do be aware that changing the shape to a trapezoid, as you show now, makes it impossible to predict the modal behavior of the room using the simple room mode calculators. They only apply to rectangular rooms, or nearly rectangular rooms. Yours is way too far out of rectangular to be predictable.

Wouldnt it be better to use the existing outer walls and build it like in the attached picture?

Well, you do need to use the outer walls, yes, but you also do need inner-leaf walls to provide the isolation between the studio and the rest of the building, as well as to define the final shape ans size, and to provide the treatment you will need. I am assuming that you do need isolation to the rest of the building? You did mention that you do Foley work, which implies a need for high levels of isolation.

- Stuart -

Take a look at this thread: http://www.johnlsayers.com/phpBB2/viewt ... =2&t=20471 Those speakers are not supposed to be soffit mounted either... they have huge bass reflex ports on the rear. And yet, after chatting with their chief engineer, and getting a couple of pointers from him (great guy), the results are what you see....

I've allready read that thread with awe

just in terms of sound - wouldn't the Ytong / cinder stones be better, as they are more "static"? - I'm not sure what you mean by "static".

I mean walls that have almost no resonance, like some poorly build drywalls. In some rooms I was, banging on a wall would generate a certain frequency, and I always thought this certain frequency would be triggered by the speakers.

But you did not mention that you could get rid of the elevator, which changes things quite a bit. That's why the forum rules ask that you include everything in your initial post, to avoid making suggestions that might not actually fit well. You also did not mention that it was possible to eliminate the door and passage at the lower right of your drawing.

Yes, right, my bad, my not-dotted line was misleading, I should've marked the right door as removable.
We just found out yesterday we can remove the lift!

However, do be aware that changing the shape to a trapezoid, as you show now, makes it impossible to predict the modal behavior of the room using the simple room mode calculators. They only apply to rectangular rooms, or nearly rectangular rooms. Yours is way too far out of rectangular to be predictable.

that means I can't really plan flush mounts by calculating?

One question on that topic and flush mounting I couldnt find an answer yet:
why cant I just build a movable flush mount? I've been told that basstraps do not have to be flush with the wall. I thought there can be a gap, as the points that are to be treated for bass absorbtion are not on the wall, but a bit away, like 30-40cm(supersonic). If thats true, a moveable flush mount like in the picture would enable me to finetune the best spot for the speakers after construction.
http://imgur.com/a/dpW5x (sorry, tried uploading it directly here like 20 times, not working)

Wouldnt it be better to use the existing outer walls and build it like in the attached picture? - Well, you do need to use the outer walls, yes, but you also do need inner-leaf walls to provide the isolation between the studio and the rest of the building, as well as to define the final shape ans size, and to provide the treatment you will need. I am assuming that you do need isolation to the rest of the building?

Allright, I am going to make some tests with drums, if they can be heard at all. The only issue would be if you could hear them behind the entrance door. But as we want to install a new door here anyway, we can soundproof that one. The building is pretty quiet, I had no trouble recording foley or other quiet things yet!

I mean walls that have almost no resonance, like some poorly build drywalls. In some rooms I was, banging on a wall would generate a certain frequency, and I always thought this certain frequency would be triggered by the speakers.

All objects in the universe have natural resonant frequencies. Even planets, and entire galaxies, as astronomers have recently discovered (although I'm not sure you'd call that "acoustic", if the wavelength is measured in light-years! ) Even limp-mass objects have resonance, albeit extremely well damped. Your concrete walls will have resonant frequencies, just like everything else: tap one with hammer, or thump on it with your fist, and you'll hear at least a couple of them... You'll find that they are surprisingly high, and rather audible. If they are audible, then the wall does not isolate. The laws of physics show that you only get isolation starting at about twice the resonant frequency, and above. So if you can hear the resonance, the wall is not isolating that part of the spectrum, and an octave either side.

But isolation does not depend very much on the resonant frequencies of the individual parts of a wall: rather, it depends on the resonant frequency of the wall as a system. The whole is greater than the sum of its parts. Even though the parts do have their own resonance, it's the resonance of the complete MSM system that matters most.

that means I can't really plan flush mounts by calculating?

The modal response of the room is not related in any way to the design of the speaker soffits. It is, however, related to the design of the room itself. If you don't have good, even, smooth modal spread, you'll be chasing your tail forever in trying to treat the room. For example, if you have two axial modes that happen to line up within 5% of each other, or maybe an axial and a couple of tangentials, the modal ringing at that frequency will be multiplied, and you'll find it really hard to kill it. While soffits might have an effect on the modal distribution of the room, they are not the primer reason (not even a secondary reason!) for building them. The prime reason is to eliminate most of the grave artifacts caused by having a speaker inside the room.

why cant I just build a movable flush mount?

I'll answer your question with another question: Why would you want to move your soffit? In fact, I'll make that into a series of questions? How would you get the crane into the room to move it? Considering that it will weight several hundred kilograms, a crane is about the only way you'd ever be able to move it... And if you did move it, how would you get it back to the only location where it works? Soffit mounts are carefully designed to focus the sound exactly where it needs to go. If you move it, even a little bit, then the sound will not be focuses correctly, and you will not have a good stereo image, nor will you have a clean, balanced, broad, accurate sound-stage. When we built the soffits at Studio Three, the final alignment was done with lasers, and is accurate to within a couple of mm. Considering that the wavelength of sound at 20 kHz is just 17mm, if the alignment is out by even 8mm, that's an entire half-wave, and therefore would cause phase cancellation. Even 4mm is a quarter wave.... So how would you manage to get your soffits aligned again with precision, after bringing a crane into the room to move them?

I've been told that basstraps do not have to be flush with the wall. I thought there can be a gap, as the points that are to be treated for bass absorbtion are not on the wall, but a bit away, like 30-40cm.

That's one of those myths that seems to be propagated and repeated all over the internet. It is true... only for "normally incident sound", meaning sound that approaches the wall head-on, at a 90° angle. For sound approaching at any other angle, there will be velocity variations at the wall surface. So for "randomly incident sound", it is not correct. And considering that most of the sound in a studio is randomly incident, or at least not normally-incident, putting insulation against the walls is a smart thing to do.

Yes you can lower the frequency range for which a porous absorber is effective by moving it away from the wall, but you could make it even more effective by filling the air gap behind it with even more insulation.

Yes, you can build bass traps that consist of nothing more than a panel of insulation material placed diagonally across the corner, and it will be somewhat effective, but for optimum performance, nothing beats the Superchunk bass trap, which has insulation right up to the wall. The entire "triangle" of the corner is filled.

Besides, soffits are not bass traps (although they can include bass traps). Soffits are designed to mount speakers. That's the primary purpose. They can also be designed to include some limited bass trapping, but that's only a secondary purposes, and isn't always possible.

If thats true, a moveable flush mount like in the picture would enable me to finetune the best spot for the speakers after construction.

No, actually it would not. If your soffits are design correctly, they will automatically be in the best spot. Moving them would take them out of the best spot.

Allright, I am going to make some tests with drums, if they can be heard at all.

You seem to be misunderstanding the purpose of isolation in a studio: it is not just about stopping sound getting out (although that is part of it). It is also about stopping sound from getting in! You are in a building: there will be noises in that build that you must block if you hope to track, mix, and master well (especially for Foley! That's the most sensitive of all recording). There will be noises like water in pipes, toilets flushing, people walking, talking, cell phones ringing, radio, TV, vacuum cleaners, pumps, fans, doors opening and closing, as well as perhaps traffic noise from outside, thunder, wind, rain, aircraft flying over, helicopters, sirens (fire, police, ambulance, etc.), and a thousand other things. Isolation is as much to stop those coming in, as it is to stop your music getting out. With Foley recording more than anything else, you are working with very tiny sounds that need to have the gain increased very greatly to be usable: when you do that, the background noise gets amplified along with the sound you actually wanted, and there's not much you can do about that.

If you want to be able to do Foley, then you do need very good isolation.

The background noise level in buildings is defined according to to NR curves (or NC curves: pretty much the same thing). For a typical studio, you need NR-20 at least, and preferably NR-15. For serious Foley work, you need NR-10. That's very, very hard to get.

But as we want to install a new door here anyway, we can soundproof that one.

Ummmm.... you should probably do some research on "mass law", to understand why that won't work...


- Stuart -

dear Soundman2020,

thank you alot for your explanations. I looked deeper into everything you mentioned and took it all into consideration.

I came up with the following now. I think some of the informations I gave were not clear enough, but I am quite sure that this construction will work out fine, regarding neighbours and studio acoustics.
I will have the speakers freestanding for now, because I havent got my final speakers yet.
the blue lines are 24cm and 17cm lime-sand brick (hope thats the right term). For the thinner wall, I am not sure yet how thick it should be.

The two big questions right now are HVAC / ventilation, I will open another thread for that so it'll be more searchable.