RC2-> Ceillings / Madson Isolator Clips-> Walls

Fellow Studio builders, Just finished reading Rod's book and considering the existing room I need to deal with to design and build my studio I tried to figure out what would be the best option for me and my wallet. I've been thinking about a few stuff to uncouple inner wall and ceilling from outer ones: Let me know if this would be a good idea or not. In advance thanks. I'll have a lot of other questions later... :wink: benoit

I'm not quite sure what you are trying to do there, but that doesn't look like it will work, for many reasons. Is there any reason why you cannot just build a normal "room-within-a-room"? from your diagrams, it looks like it should be possible, since you are talking about putting in wooden "beams" anyway. So why not just build a normal fully decoupled stud frame for your inner-leaf? - Stuart -

Thanks Soundman, I am for conventionnal studio building with fully decoupled inner box as you say. A friend architect asked me to post these sketches to know if it would be a great idea or not. He's trying to convince me to simplify the building process but to my personal knowledge there are no other reliable way to have a good insulation. I do agree with you 100%! I have to convince them and maybe adapt just a little bit to the place, find a few tricks to make our life simpler... My friend is not confident at all with the fact that steel stud walls with 3 layers of 13mm plaster wall will auto-support a ceilling with the same triple layers. And I have to say (This is my first building project but I have at least 5 people involved in the construction used to build houses but have no studio insulation knowledge) that I have no idea how to make steel stud walls strong enough for supporting themselves?... Do we have to couple this to existing walls/slabs at some point with special clips or resiliant for strength purpose? In Rod's book every sketches are based on wooden frames so should I only have to fully transpose these principles to steel stud construction? I'll use floated floors but this doesn't change that much... I'm just thinking out loud, like I did on every post sent earlier I will work on that today by my own (thru here and rod's book) and of course any clarification is more than welcome. My point here on this forum is not waiting for permanent rescue (even if appreciated a lot), more like an open diary so please stop me everytime I'm saying or planning stupid stuff. Have a great day benoit

Oh, one other thing. I'm trying to figure out something about ideal ratios for my CR. Are these ratios for inner walls? outer walls? I plan to use a standard rectangular shape for inner walls with side walls and ceilling angled a bit (10° approx, larger at the back wall). I guess this ratio would be for maximum length and height, so for the back wall. Am I right?

Hi again Soundman2020, I found this in Rod' book, Figure 4.22 "Ceilling with dual-legged resilient channel" Am I missing something or my sketches up there are something similar? Maybe this principle will not insure 60 dB Insulation 'in addition with the outer existing concrete wall) I will need but I want to understand why Rod says "Resilient channel works well on ceillings as it does on walls, although I would recommend the use of the double leg system" and how it's different from the sketches posted. Here is Rod's sketch. cheers and thanks

I'm trying to figure out something about ideal ratios for my CR. Are these ratios for inner walls? outer walls?

Inner walls. The ratio refers to the inside dimensions of the final finished surfaces of your inner leaf, prior to installing acoustic treatment. In other words, it is the walls that you will see when you stand inside the room right after you put up the final layer of drywall, but before you hang absorbers, resonators, etc.

I plan to use a standard rectangular shape for inner walls with side walls and ceilling angled a bit (10° approx, larger at the back wall). I guess this ratio would be for maximum length and height, so for the back wall. Am I right?

That's a real hard question to answer! I've been asking that myself for a while now, but nobody seems to be able to give an absolute answer. Personally, I reckon the best idea is to go with an average for your non-parallel surfaces. My reasoning (and I may be wrong here) is that for the wavelengths that are of the most concern, at the low end of the spectrum, the difference between the dimension at one end of the wall and at the other end doesn't seem to be significant. It's just a small fraction of the wavelength, so averaging out seems to be the reasonable thing to do. However "reasonable" isn't always "right" in acoustics! By the way, your side walls need to be angled at 6 degrees each (total of 12°), and your ceiling needs to be angled at 12° too. Everything starts narrow at the front (where the speakers are) and gets wider/higher at the back. Assuming that your speaker axis intersect angle will be 60°, of course. If the speaker intersect angle is higher, then the wall and ceiling angles also need to increase. I don't have the exact figures on hand, but I seem to recall that you need 22° ceiling and 11° walls if your speaker intersect goes up to 90°. Basically, the entire room geometry needs to be based around your speakers, so that's the first item you need to get right: Speaker location vs. mix position. Once that is in place, the rest of the room geometry kind of falls into place fairly easily. - Stuart -

Ok Stuart, I just spoke to the guy who will handle the furniture for the desk and speakers and everything. I have to run for now but I'll figure this out tomorrow. Anyway I'm really used to something close to 60° with equilateral triangle monitoring position. I'm kind of traditional in that point of view with a sweet spot where I'm seating at 38 or 40% length from the front of my actual room and I like it too when I go in other places for recording or mixing. I had a meeting with a friend of a friend... which is an architect this evening, the project will be quiet expansive (Of Course...) and this is very stressful trying to teach insulation and typical construction process to someone which is working in the industry but not specialized in recording studios... These guys always dispress me... When I read forums, everything seems to be possible with a few thousand €, and when I talk with these guys I cannot mount a vocal booth tripled drywalled for less than 50K€... Truth should be somewhere in between 10 & 50k€ but this is a world! Ok, I have to go but thanks Stuart, really appreciated. benoit

Benoit - I have never had the need to use triple layers of drywall in any of my designs. The max I've used is 2 layers and the most common is one layer. cheers john

Hi John, I thought the only rule was mass, mass, mass that's why I was planning to use 3 x 13mm plaster wall per leaf. Are you used to design everything with 2x13mm plaster wall only per leaf? What about the green glue Rod is talking about? I have to say that I will need strong soundproofing cos of the neighboors living above the futur control room and vocal booth. I have not much time to give you more details, and I know that everything is based on details when you're talking about studio design and construction. It's probably time to reveal the whole plan here to obtain really accurate answers to fit my specific project... I need some rest, my brain is boilling thinking about all this project. If you can say that a double layer (well built) will do the job you'll save my life, I'll save money, my partners will stop thinking I'm a fool, everyone would be very happy with that! Have a great day. benoit

I said 2 x 16mm drywall ;)

Got it!!! :idea:

So basicaly, I have to make it short, accurate... What I'm trying to achieve is definitly to build a professional studio. This will be a recording, mixing, mastering, place. I will be the main producer working in it but my goal is also to have soon something like 30% of external producers working in there. That states that the studio needs to be easy to understand (acoustics, technical stuff, wiring...). As we are expecting this place to be a real professional studio we cannot be mistaken talking about isolation from the rooms to the adjacent offices, and to the appartment right above the control room. The building is a kind of old school factory buiding, all made with concrete slab (probably very thick more than 40cm at least) and concrete walls (20cm at least). So with adding 200mm rockwool to existing walls I think we'll have a good outer leaf. On one side of the control room we'll have to build concrete walls (or 2x16mm if someone can say it would be enough to keep offices safe). Talking about the offices, i'll be renting them to a graphic designer, a stylist, a video producer so we need them to be able to work without being bothered by our studio work. Same thing for neighboors upstairs. We can build in there a CR (25m2), a vocal booth (12m2) and a tracking room (50 to 80 m2) with a minimum of 3.6 meters ceilling and a maximum @ 4,20m. I will do a large palette of music styles, from folk, to metal, to smooth jazz and i'll be at 50m from one of the biggest classical music college in Lyon so I'm in right to expect to do more and more classical music. The building is downtown, but 100m away from the closest street in a peacefull garden with another company which is building toys next door. So except a few children screams coming from the school the place is quiet calm (for a downtown building I mean). Don't have any dBmeter, cannot give you more informations. What I know is that I'm used to mix at 85 dB and like to master (when it's heavy music) at 95 dB or something. So from outside to inside my plan for soundproofing is: -Concrete slab/wall -200mm rockwool -100 to 200mm airgap -200mm rockwool -2x16mm drywall (plaster wall) I'll have windows (3 at least with a size around 1mx2m for 2 of them, the other is a giant one (existing) 2,5x2,5m) and 4 doors way to build. Talking about the floors (I had troubles to find something that worked for me) I think I will put between 10 and 20 cm of DRY sand. That would allow me to wire everything thru the floors and to float a wooden deck without risking to make it resonate like a guitar body when we'll push up the volume. I have rough sketches of all this, but as I really suck at sketchup and the sketch the real estate agent gave me is not accurate at all I'm a bit tired to draw unusable stuff. Inacurate for inacurate, my rough sketch should help anyone to understant what the project is. To talk about my expectations in the acoustic world, to be honest I'm not a big fan of absolutely under control rooms (with pre calculated resonators, hangers...) and this for 3 reasons: -the first one is my understanding of acoustics is not good enough and I'm a producer, not an acoustician so the less time I'm on building process, the earlier I'll be doing my job and making money. -the second one is I've been lucky to work in quiet big facilities but for the main reason that they are built in and as a house are considered as project studios. I've been releasing recently top Chart records monitored in minimaly treated spaces and I won't have too much money to make it perfectly right from the beginning. -the last one is depending on the first one. I would like to be able to reach the exact ambiance I have in mind in CR and even more in the tracking room. As I don't master the theory I would like to improve stuff step by step, by being in the room and listening to it, feeling it, trying stuff. I don't want to be stuck with resonator walls and that's it. i do prefer acoustic treatments like Gik acoustic, or even a nice carpet... I might be wrong, but I feel this way I can understand and control the whole process. I want to be confortable with the whole project. Suprises will probably be there on time, I don't want to start with some dark points that I'll be waiting for with fear... The last thing is I'm a construction noob, fortunately 2 of my partners used to rebuild houses, appartments etc... I'm just trying to translate recording studio specific processes for them. I think we'll also try to find contractors, and/or someone strong, smart with a lot of construction background to help us with drywalling, electricity and windows during 2 months or something. What am I expecting? This to work. My first preocupation is about soundproofing. Will it be enough? Then I will have to find technical solutions to a few construction details I need to be sure of. This will be for a futur post. Now if anyone has any suggestion about stuff to redesign... you're more than welcome. thanks for reading benoit

Talking about the floors (I had troubles to find something that worked for me) I think I will put between 10 and 20 cm of DRY sand. That would allow me to wire everything thru the floors and to float a wooden deck without risking to make it resonate like a guitar body when we'll push up the volume.

Wouldn't it be easier / faster / cheaper to just set up all your wiring conduit laid out on your existing slab, then pour 10cm or so of concrete over it for your new floor?

to be honest I'm not a big fan of absolutely under control rooms (with pre calculated resonators, hangers...) and this for 3 reasons:

That's fine for your booth / live room, but for your control room it really does need to be "absolutely under control". If not, your mixes will never translate well.

As I don't master the theory I would like to improve stuff step by step, by being in the room and listening to it, feeling it, trying stuff.

That's also fine, as long as you start with a basic layout that will allow you to do that! If you start with an acoustically bad layout, there is absolutely nothing that you can do afterwards to "get it sounding good", no matter how hard you try. For example, if you start with a cube-shaped control room, or one that has a curved front wall, or is asymmetric, or if the mix position is at the 50% point, or if the speakers are right in the corners a million other potentially really bad designs. Start with one of those and you will never make it sound good, regardless of what you do. You have to start with at least some understanding of acoustics for your basic layout, or you'll waste a lot of money and end up with a disaster. Maybe what I'm about to say here will appear blunt and insulting, but your approach to design is equivalent to a hopeful "musician" coming along and saying "I don't master the theory, so I'd like to improve my guitar playing step by step, just listening to it, feeling it, trying stuff, but never bothering to learn what chords are, what scales are, or music theory, never taking any formal classes (or even informal), just kind of muddling along until I get it right".... In other words, just as in learning to play the guitar, for studio building there are some very basic principles that one just HAS to learn and understand.

The last thing is I'm a construction noob, fortunately 2 of my partners used to rebuild houses, appartments etc... I'm just trying to translate recording studio specific processes for them. I think we'll also try to find contractors, and/or someone strong, smart with a lot of construction background to help us with drywalling, electricity and windows during 2 months or something.

this does not sound like a good plan to me. That's just my opinion, of course, for whatever you think it is worth, but having a half dozen people working on a studio, none of whom has any experience or even inclination to learn about basic acoustic principles, sounds like a recipe for failure. Just because someone knows how to build an apartment does NOT qualify them in the least for building a studio. Just because some knows how to wire a normal house does NOT qualify him to wire a studio. etc. Just as with basic design, ignorance here exposes the build to numerous serious errors, any one of which could potentially destroy the acoustics of the rooms. For example, if the drywallers try to build the walls the way they normally would for an office, then they will be wasting all of your money, period. All other efforts at good isolation and good acoustics will be pointless. If the electrician tried to install the light switches, plugs, wiring, distribution panels, grounding, etc. in the way he normally does, he'd trash thousands of dollars worth of carefully constructed isolation and also wreck your chances of a hum-free studio. If the glaziers tried to install the windows the way they normally do for a house, there would be totally ineffective isolation between your rooms and to the outside, so all your money invested in walls, floors, ceilings and doors would be wasted. If the carpenters were to install doors the way they normally do for an apartment, ditto: No isolation, wasted thousands of dollars. If the HVAC company tries to install the HVAC system like they normally do for a commercial building, the live room and control room will both be unusable for their intended purposes, even with the HVAC system turned off. etc. Building a studio without knowledge, and without even the desire to learn, seems like a 100% guarantee of failure, to me.

What am I expecting? This to work. My first preocupation is about soundproofing. Will it be enough?

will WHAT be enough? You haven't siad much about what you want, nor have you posted your design specs, nor your construction details, other than to mention a rough outline for wall and floor construction. What you propose might work, provided that your ceiling, doors, windows, HVAC and electrical are all done correctly, that there are no flanking paths, that everything is hermetically sealed correctly, fully decoupled correctly, etc. Otherwise, the answer is no, it won't work.

to help us with drywalling, electricity and windows during 2 months or something.

2 months???? That is entirely unrealistic. 2 years would be more like it. In 2 months you can maybe (and that's a really big "maybe"!) get your rough design together, on paper, ready for review by the structural engineer and relevant authorities. I doubt you can even get the necessary building permits inside of two months!

Now if anyone has any suggestion about stuff to redesign... you're more than welcome.

Doors. Your doors from the CR to the LR and from the CR to the booth are in the exact locations where you will need acoustic treatment: Basic acoustic treatment, not optional acoustic treatment. Booth: That's a really awkward shape, and is basically laid out as one resonant cavity connected to another. Multiple parallel surfaces. My guess is that you'd have a rather lousy sound in that room, very difficult to treat acoustically. That's my first 2 impressions, for what it's worth.

Ok Stuart, I think we're misunderstanding eachother... I agree on 90% of what you said: -acoustics need to be right in the CR -contractors are a big potential failure of the project -I cannot count on people that don't know precisely what technical specificities a studio construction requires -I should be mistaken if I say that 4 full time people could do that in 3 months, am I? I consider myself a main help in construction work and hope to catch the basics (I mean reflexes, not theory) asap. I also consider myself as a supervisor at the same time, looking for any details that could screw things up (and my money at the same time). But if you think I cannot do that what I can offer is a Return flight; for anyone interested in having 2 months here in lyon to build a studio. I'm not kiding, I can't find anyone interested in that here so think guys that I'm more than serious. Please come, make this project work come on!!! Then I'm not totally ignorant in acoustics. I probably need to put it right, my purpose was to say that I wasn't mastering acoustics when it comes to use all that softwares and read the results properly. I know I can learn, I can learn fast but I will see this approach later. For now I know I do understand acoustics well enough to take roughly the control of a room. Mine at home is fine but so small that the right sweet spot is 60cm wide and I've been able to release stuff that you can get on radios and reached the 20 top charts in the UK, france, canada these last years so I'm not worried about that. I mainly now how to listen to music, and how to listen to a room with the same music. I mean enough to cut fine mixes and good masters. It won't be "The Exchange", or "Ocean Way" but I do need a room and it has to fit with my budget. I don't have any other choices for now. I can deal with technical stuff, not with my skills and other buddy's ones. My basic approach is of course to keep symetry, 6° angle each side wall and 10° for the ceilling, head positionwhile mixing at something like 35 to 40% of the lenght from the front wall... The PDF attached with my previous mail are far away from reality (measures are definitely wrong and I'm waiting for new ones). Room are roughly designed on it too. I already drawn non-parallel rooms and I'm waiting for better plans to be able to fixe a few details like available space for doors with acoustic panels, walls details etc etc... but at the same time I don't see why I should zoom that far into details if I take the basics as a fact; this has to be done that way, the way you can see in every figure in Rod's book or everywhere on this forum. I don't have any other sketches for now, people are still working in this place for now, they will be leaving at the end of the month. I know the road is long but the only thing that counts now is to move forward on this project and I have to say that I'm not landing on this forum as a musician which would be expecting a "Eric Clapton solo feel and sound" with a peavy guitar plugged into a Valvestate 80! I've been working on this project for 3 months, starting from scratch, alone... I do think your sentence about musicians was a bit insulting, I'm not the kind of guy who think he gets everything anytime I turn a page in Rod's book. I hate being in the studio with on of this fake musician who think they can hide their lack of technic or practice behind arrogance... Maybe for you I'm one of those but it took time and it will again, I know it, but everyday things are getting clearer and I still don't have the main answer to the most basic question that would definitely determine if the rest of what we're talking about is possible or not: So, in therory (and a big dose of your experience guys) and what you know about my project, should I be expecting enough insulation between the studio 3 rooms and the rest of the building? I mean what kind of STC if we consider that I didn't fail in any construction step? And maybe how long with 4 people full time?... PS: we don't need permit, don"t have inpections for that kind of project here in France and this project is followed by an architect specialized in industrial structure, he's used to build stadiums. Have a good evening guys benoit

what I can offer is a Return flight; for anyone interested in having 2 months here in lyon to build a studio. I'm not kiding, I can't find anyone interested in that here so think guys that I'm more than serious. Please come, make this project work come on!!!

Seriously, Benoit, maybe you should talk to John about doing exactly that. That's what he does for a living. He designs and builds world-class studios. He takes care of figuring out all the acoustic details and the construction techniques so you don't have to And he's also a world-class sound engineer (just take a look at his credits), so he understands what you need, since he's been in your shoes for decades. Maybe that really would be a very, very good solution, if you want a great studio done fast, professionally, and with success. - Stuart -

Yep, you're probably right. So let's write something directly to John and it was a pleasure to speak to you Stuart.