New Studio build! Calgary AB.

All right! After 6 months of reading through this forum and other research I think I am finally ready to start the design of my new studio, dubbed "The Playground of Sound" TM =^). To give a little background, this will be my second studio, the first being a small project studio in the detached garage of my previous residence. I was only renting at the previous spot, and unfortunately the landlord is tearing it down to build a infill. Instead of going through all the effort to re-build the studio in another rental I took a step forward and bought myself a house. The place I bought was the best compromise between location, price, and size I could find. That being said, it does have its advantages and disadvantages. The house is in a fairly quite neighborhood in the "not too far" suburbs of Calgary, Alberta Canada. The main reason I chose this house is it has a large (24'x 22') detached garage with high (10') ceilings in which I intend to build my studio. I have one close neighbor whose house is about 20' away from the garage. I record everything from classical guitar to full rock bands (I try to stay away from anything to heavy/loud) and I am a drummer myself and I practice at least 2hrs a day, so sound isolation is going to be important. I am planning on building a room within a room 2-leaf double stud setup in the garage (with 2 layers drywall and GG on inner leaf), basically one big room for instruments and maybe a small iso booth for vocals (studio will double as a jam space for my 12pc. Funk band). I was originally going to build a small control room cutting diagonally across one corner of the garage, however I have decided from what I’ve read, that such a small control room is really pretty useless and no good for mixing in. Therefore I am planning on building an addition onto the garage for the control room. I have researched this, and apparently I can get a building permit to build up to a 130sqft addition without needing a development permit (which would be expensive as well as up to the discretion of the city). My budget is currently around 10k at least for the basic construction (I can save up later for flooring, lighting etc.). The plan is to build 130sqft off the front of the garage next to the 4x8 window that will become the control room window. I have uploaded a sketchup drawing showing the layout of the existing garage as well as the proposed addition (13'x10' in this example). The mixing desk would be at the end of the room with the window into the live room to the left of the desk. I was thinking of having a identical window to the outside on the other side of the room for symmetry and to allow light through to the live room. I will have some heavy curtains on both windows that I can pull across when mixing. Are there any significant reasons I shouldn't do this? Currently both doors will open to the outside, After inspections I intend to build a small airlock with a third door so you don’t have to go outside to get from the CR to the live room (I am allowed to build a 40sqft addition without a permit). The roof of the control room will have a ridgeline perpendicular to the existing roofline and will intersect the other roof. This will allow my to keep the ceiling height as high as possible in the control room. Assuming the ceiling is 10' high what would be the best ratio of the walls in terms of modes and such? 130sqft is my max outer dimensions, so the interior will be slightly smaller, I am toying with the idea of doing staggered stud walls or maybe double stud inside out walls in the control room. Any other suggestions on layout? I cannot thank you guys enough for putting up this forum; you've already saved me from numerous errors (my first plan had 4 leaf walls!) I won't forget to keep a donation to the forum in my budget...

Hai DbD, welcome to the JLS forum. I've read the introduction and can only say that adding the CR is a good plan. The sketch you provided are only the outerwalls, right? I'm sure your're gonna do sketch which included the innerwalls plan etc. I didn't understand the "staggered studs" part tho.. but you'll prolly figure that out when designing (and learning) your new studio!

Thanks for the reply, Yes those are only the outer walls, just for reference with what I am starting with, and to show the location of the proposed addition. I am working on a sketchup model for the interior design, but was hoping to get some feedback on the control room dimensions before I get into too much detail. The drawing shows a 10'x13' CR, I have modified that since then to 9'x14' as that gave a little better modes from what I could understand from the calc spreadsheet in the reference thread. I suppose I must first decide on the type of walls in the control room. I am thinking of continuing the 8" concrete footwall that surrounds the existing garage around the CR as well which would give me a wide enough base to have a double wall on top of the footwall, and then build the inner wall inside-out. It would be tight to stand a 8' wall up inside a 9' room however so I might have to make it outside-in. Anyway if my interior is 8" smaller on three faces than my max outer dimensions of 130sqft (the face connecting the addition to the existing garage wall will have a second wall on the garage side so there is no need to double up that wall) That would give me interior dimensions of 12' 8" x 8' 4" for a outer dimension of 14'x9'. How does that work acoustically? Since I am limited to 130sqft I can't go any larger, but I can play with the ratios. I have the control room window to the left of the mixing desk because unfortunately I cant place the long dimension perpendicular to the window as it would run into my deck on the house. Is this a problem? I know most studios have the window in front of the mixing board, although it seems most of the time the mixing desk and computer monitors seem to take up most of the viewable area anyway.

I talked to the building permit office yesterday and found out that since the addition will be attached to the detached garage and not the actual residence it doesn't fall under the same limitations for a MRA (minor residential addition) which was what was limiting my dimensions to 130sqft. Apparently I am able to go up to 74m2 including the existing garage which leaves me about 250sqft available (budget permitting) . I will have to do some re-thinking as the 130sqft control room was starting to look pretty small once the interior walls were in, I will probably go up to around 200sqft which should give me room to splay the walls properly. regards, -jER

Death By Darwin wrote:

...which would give me a wide enough base to have a double wall on top of the footwall... ...the face connecting the addition to the existing garage wall will have a second wall on the garage side so there is no need to double up that wall

It's hard to predict but maybe you should read and think about flanking sound transmission. Maybe something could damp the sound transmitted from one wall/leaf through the concrete footwall into the other wall/leaf. Also your sound insulation from your CR to the outside will be decreased because of the same flanking reason (

the face connecting the addition to the existing garage wall will have a second wall on the garage side so there is no need to double up

). The mode questions: Maybe some visualizations would help. Just an example for different heights for your 12' 8" x 8' 4" idea. With your 200sqft you have even more options to try... good luck!

Andymel, Thanks for taking the time to look at this for me. As for the flanking through the footwall, I was kind of viewing having two walls sitting on top of the 8" concrete foot-wall as being functionally similar to having two walls sitting on an 8" concrete slab (which unless a floating floor is installed would be common practice) however I guess since there is no dirt adjacent to the foot-wall to provide dampening this might not be an accurate analogy. Maybe I should think about building the inner-leaf on the floor like I am planning on doing in the live room; That or build some garden beds around the outside of the CR to pile some dirt up against the foot-wall. I was going to try to sandwich some neoprene or rubber or some kind under the walls on at least the inner leaf (the outer leaf of the CR will be load bearing and I doubt if the inspector will like having rubber under it). I am still a little confused on how to analyze the results of the room mode graphs. Is the goal to reduce the number of spikes on the graph? or the amplitude of the spikes? or the spacing of the spikes? or D) all of the above :). Are there any guidlines on what a good room should look like using this calculator? I looked at some of the known good rooms in the program briefly but the differences were hard to observe, at least for a noob :wink: Thanks again, -jER

I have answered some days before, but then my browser crashed. :? Once again, briefly...

Death By Darwin wrote:

Maybe I should think about building the inner-leaf on the floor like I am planning on doing in the live room

Yes it's all about damping inside the mediums and maximizing impedance at joints. I neither have the practice to know nor the knowledge to calculate it, but I would recommend to build one wall on the floor if you have room to do so. On the other side, concerning room acoustics the smaller room may be of more problem than a little bit less insulation?!

I am still a little confused on how to analyze the results of the room mode graphs. ... I looked at some of the known good rooms in the program briefly but the differences were hard to observe, at least for a noob :wink:

As the number of modes is fix as long as you have your boundaries, you want the negative effects to be as small as possible. Our intent is to achieve a mode distribution that is as equal as possible. A number of modes close together will boost the reverberation time in this frequency range (less damping = longer lasting energy). Because of the same number of modes in every rectangular room such a accumulation will lead to other frequency ranges with wider gaps between the modes resulting in a much shorter reverberation time. What you want is similar reverberation in different frequency ranges...therefore...equal distribution. good luck :)

Hello again, So after much deliberation I have figured out my optimum size for the addition for my control room as far as layout, physical feasibility, and city requirements. I would like to build the control room 14'x12' with a 8' or 9' ceiling (or around there). Once the interior leaf wall is installed the interior dimensions will be more like 13'x11.5' although the width will vary with the splayed walls and such. Here are the saved parameters for Andy's calc program. Cntrl Room 9ft/396/350/274/343/200/ Cntrl Room 8ft/396/350/243/343/200/ It looks to me like 9' ceiling would be much better that 8', but I am still not very good at interpreting these graphs. Any suggestions before I submit my plans to the city? I am still at the point now where I can push some of these dimensions around a bit, but not for long...

Update: So I have finalized my control room addition plans and submitted the drawings for the exterior of the addition (the only part the inspectors are going to get to see) and am awaiting a building permit in the next couple days. This was much harder to obtain than I expected, the city required plans to a specific scale (1/4"=1') including 7 different types of drawings (Front, back, left, right, floor plan, site plan, cross-section) as well as detailed truss profiles from the truss manufacturer (they required I used engineered trusses for my shed sized addition!) which the truss company screwed up a couple times (you would think a company who build roof trusses could read a set of to scale drawings...) before they would reveiw the permit which ran me $200. I also got locates for my service lines and found out that I have both an electrical main and a gas primary running directly under my garage and addition. Took 2 weeks to convince both the city and the gas company to let me build over top of the gas line, however they finally conceded on the basis that I wasn't going to be parking any vehicles in the addition. I spent this last weekend digging out all the sod and top soil where I am pouring concrete as well as hand digging 10 four foot deep 8" pile holes to support the foundation. I am hoping, pending acceptance of my permit and the weather to pour concrete this sunday! Anyway I have attached a drawing showing a really basic wall layout for the control room. Interior leaf walls for the main live room are missing, but will sort those out and post them soon... Any comments or suggestions are encouraged! Regards, -jER

I should add that the finished ceiling in the control room will be around 9' high and supported by the interior leaf. The windows are all 7' W x 3.5' H.

Update: So after almost a month waiting for the city to issue me a building permit I finally got it in my hands this Thursday! I could never have imagined I would have to jump through so many hoops to to obtain a permit to build a large shed sized addition on a garage. However it is what it is, and I got it just in the nick of time seeing as I had already ordered concrete; so progress trudges onward. I spent almost every day this past week digging out sod and dirt, shoveled in 5 cubic meters of gravel, formed and poured 4.5 meters of concrete (pad for control room as well as a nice stamped concrete pathway from the studio to the house. It looks great, I will try to take some pics tomorrow if I can borrow a camera. It was a lot of work for one week, done mostly by hand by myself and my trombone player (who also finishes concrete =^).

So I still haven't managed to borrow a camera, but here is a basic wall layout for the studio, CR & LR. How does this look to you guys? internal treatment is not shown, except for a couple super chunks in the corners (could be hangers instead) but I am planning of adding some hembolts resonators and absorbtion around the walls. The guitar closet is a humidified closet to keep acoustics and my gretsch happy, it has glass pane french doors across the front. Hopefully the doors aren't heavy enough to cause 3rd leaf problems. One question I have is regarding the walls between the CR and the LR. Both the CR and LR have complete room within a room architecture with their own ceilings. Since the Control room is built as an addition to the existing structure I have to leave in place the existing exterior wall of the garage as it is a bearing wall for the trusses on the existing roof. There is a large window in this wall slightly larger than the control room window. My plan is to remove all of the glass from this window so it is just a large hole in the wall, with panes of 1/2" and 3/8" glass on the interior leaf of the LR and CR respectively. Is this going to cause bad 3 leaf problems even though the wall is not sealed? (Large 7' x 4' hole through wall) I can't use this wall as a inner leaf on either side as it will flank to the roof but I can't remove it... -jER

Hi, Happy Canada Day! The only issue I am seeing right off the bat is that these windows look like there going to be right at your first reflection points. Regards, Steve

I hate to suggest this, but it may be easier to rotate the inside orientation of the control room so the window is at the front. The measurements between length and width are close enough that it may be a worthwhile compromise. Steve

I am hoping the 6deg splay on the walls will reflect the first reflections of the low end behind the mix position, and cover the windows with some heavy blinds or even some kind of swing down cloud -> gobo type deal for when mixing...

Death By Darwin wrote:

I am hoping the 6deg splay on the walls will reflect the first reflections of the low end behind the mix position

Do not hope. Do ray tracing freom both speakers to the edges of the listening area you want. Andre

Is it alright to assume sound waves will reflect at an angle equal to the angle of incidence similar to as in optics? Do you need to consider the full spread of the monitors speaker or just a direct ray down the center?

Is it alright to assume sound waves will reflect at an angle equal to the angle of incidence similar to as in optics?

For high frequencies, yes: You can think of them as traveling in straight lines, and angle of reflection is equal to angle of incidence.

Do you need to consider the full spread of the monitors speaker or just a direct ray down the center?

Full spread, in all directions (3D): up, down, left, right. - Stuart -

Thanks for the quick response stuart! I am still not quite sure how to draw this ray diagram. I haven't been able to find a spec on the dispersion angle of my specific monitor (being older 8" tannoys) but my logic would figure that it would be at very least 60deg. If my soffit walls are angled at 30 deg would that not make the opposite soffit wall the point of first reflection? What would you do with the space shown? p.s. any thoughts on the three leaf problem posted earlier? Thanks again, -jER

Death By Darwin wrote:

Thanks for the quick response stuart! I am still not quite sure how to draw this ray diagram. I haven't been able to find a spec on the dispersion angle of my specific monitor

Use the angles to cover the listening area, not those of the monitors. Andre

Is this picture adequate to show whether or not early reflections are going to be a problem or do I need to show rays at greater angles?

Greater angles, and more rays. One often-mentioned "trick" for finding first reflection points in an already-finished room is for you to sit at the mix position while you get a helper to hold a mirror up against the walls and move it around all over the place. Any place where you can see either of the speakers reflected in the mirror is a first reflection point. And that includes the ceiling, too. I think that's what Andre means with his comment: You can work backwards from the listening position towards the speaker, not just forwards from the speakers towards the listening position. Also, even though speakers do tend to focus the highs in tighter "cones" than the lows, the do still spit out highs at large angles. Yes, highs are more directional and you hear them better on-axis, but even at fairly large off-axis angles you still get some highs, just at a very much reduced level. And since you are soffit-mounting your speakers, lows won't be too much of a problem (provided that you compensate for the half-space boost, of course!) My $0.02. - Stuart -

If I keep increasing the angle, eventually will I not get reflections of the soffit on the other side? Will there not always be some rays that will reflect back to the mix position unless the walls are splayed > 45deg? How can I tell whether or not this is going to create an issue great enough to warrant a significant re-design of the interior walls? Again, any thoughts on my original 3 leaf question? Thanks for your input, -jER

Death By Darwin wrote:

If I keep increasing the angle, eventually will I not get reflections of the soffit on the other side? Will there not always be some rays that will reflect back to the mix position unless the walls are splayed > 45deg? How can I tell whether or not this is going to create an issue great enough to warrant a significant re-design of the interior walls?

At the surfaces where the ray tracing shows sound within 15 ms of the first signal from the monitors, absorption is required. As it is, it looks like your windows are in that location. :cry: Yes it is a part of the design of the walls.

Again, any thoughts on my original 3 leaf question?

I went over the thread and could not figure out which is the original 3 leaf question. Andre

it looks to me that the only rays that will reflect back to the mix position would be from the very front edges of the windows only. I could rotate the control room, but that would leave only 10' or so to the back wall (I read on here somewhere that 13' was optimum and that 10' was particularly bad.) which problem is the greater evil? The questin about three leaves was on the first page of the thread, as follows: "One question I have is regarding the walls between the CR and the LR. Both the CR and LR have complete room within a room architecture with their own ceilings. Since the Control room is built as an addition to the existing structure I have to leave in place the existing exterior wall of the garage as it is a bearing wall for the trusses on the existing roof. There is a large window in this wall slightly larger than the control room window. My plan is to remove all of the glass from this window so it is just a large hole in the wall, with panes of 1/2" and 3/8" glass on the interior leaf of the LR and CR respectively. Is this going to cause bad 3 leaf problems even though the wall is not sealed? (Large 7' x 4' hole through wall) I can't use this wall as a inner leaf on either side as it will flank to the roof but I can't remove it..." If you look at the drawing that shows the interior leaves of both rooms you will see what I am tallking about... Thanks again! -jER