Help with Planning & Building of my Recording Studio

[Soundman2020]

Oops! Looks like I wrote at the same time you did! So here's the additional stuff:

I've decided that I will be flipping the CR around 180 so that the back wall will be the one with the outer window in it. I think this would really make use of that 12-14" behind the inner wall.

1) Does my listening position need to be in the middle of the room or can it be put offset and more towards one of the corners?

Symmetry is critical: You must be centered, and the room must be symmetrical about your: left half = mirror image of right half. However, that does NOT mean that the door has to be centered! You can still have the room symmetrical, acoustically, with the door off-center if it has to be off-center for other reasons.

2) For the doors, I was going to go for two separate solid core doors instead of just one massive one. Does that work?

Absolutely, yes! One door in each leaf, back-to-back, with an air gap between them. And they can both have glass in them, if you want to have good sight lines between the rooms.

I would get better isolation by not having two separate openings and combining the two (window and door) together correct?

Right.

I was hoping to have the window in front and above my mixing position

You can do that if you want, but if you also want to soffit-mount your speakers (highly recommended!) then I don't see any place to put the door! It would have to go in the middle, between the speakers.

I might even skip out on the window because the main idea is to be able to interact with the people on the other side.

I would really, really try to keep the glass in there. Visual interaction during the session is almost as important as talking to each other: you can make hand signs during a take, without interrupting the rhythm and vibe of the musicians, such as making a sign to "repeat the chorus again" but without stopping the flow of the session to chat, or visually cueing a musician to come in at the right point with a finger countdown, or whatever. Personally, when I'm tracking I like to have visual contact with the musicians, as well as intercom.

Here's a couple of photos from a studio that one of my clients in Australia built, showing how sliding glass doors can work for this. The soffits are on either side of the door:

View from the control room to the iso booth:

BRAUS-CR-to-ISO.JPG

And in the other direction, from the iso booth to the control room:

IMG_0266-Iso-booth-to-CR-SML.JPG

There are two sliding glass doors in there, one in each leaf.

1) About the silencer boxes, 11 inches thick is doable. I have 12" on the plan right now but can space it a little more to accommodate. I was planning on having approx 16" in between the CR and LR walls so there would be plenty of space there I think. Could I not just fasten the boxes on my outer or inner leaf wall without them touching anything else?

Yes. Or you could put them overhead, if there's space up there. In the studio shown in the photos above, the silencer boxes are between the joists in the ceiling above the iso booth and between the wall, and the angled wood "thingies" along the tops of the CR walls hide the internal ducts that lead from the front of the room to the back, where the mini-split is.

Here's a view of the completed iso booth inner-leaf ceiling, before the treatment went in, showing where the HVAC duct comes in from above (you can also see the space where the doors will be later, with both leaves visible):

BRAUS-iso-ceiling-in-SML-ENH.jpg

And the other silencer, at the other end of the ceiling:

BRAUS-iso-ceiling-in-other-end-SML-ENH.jpg

Here's a view of that silencer in place, taken with the camera sitting on the floor looking directly up. You can see the silencer box in place, the flexduct that feeds it, and the wooden "sleeve" on the silencer that will poke through the ceiling. This was taken just before they put they final ceiling modules in place, closing off the inner-leaf completely (both the walls and the ceiling are built "inside out" in this studio, which is why you can see the inner-leaf studs and joists, even though the room is finished).

BRAUS-ISO-silencer-view-up-from-floor-SML-ENH.jpg

Here's a view of the silencer box going in, long before they framed the iso booth walls and celing. You can see how it fits in between the outer-leaf ceiling joists, but without touching:

BRAUS-ISO-silencer-box-going-in-SML.jpg

... and comepltely mounted in place, on its nylon support straps with Sorbothane pads, to fully isolate it from the outer leaf:

BRAUS-ISO-silencer-box-in-place-ENH-SML.jpg

Another view of one of the silencer boxes in place:

BRAUS-ISO-silencer-box-in-place-02-ENH-SML.jpg

In that one you can clearly see the "sleeve", which is part of the silencer box, that will extend down through the inner-leaf ceiling, to the register. That sleeve is also isolated from the inner-leaf: the hole that it pokes through is a bit larger then the sleeve, so there's a gap all the way around, and that gap is filled with abundant highly flexible, soft caulk, to create the seal. Here's a view of that caulk around the sleeve, just before the ceiling module was raised in place around it:

BRAUS-iso-silencer-seal-3--SML-ENH.jpg

... and around the edge of the hole in the ceiling module, just before it went up around the sleeve:

BRAUS-iso-ceiling-seal-2.jpg

Frank did something similar for his studio, except that I designed it from the ground up to have decent space for the silencer boxes above the rooms. You can see the silencer boxes poking through the ceiling in his thread, I think. If not, I'm sure he has photos of that, so you can see how he did it.

2) About Supply and Return vents. I've read that it's best to have the supply at the top of the walls or in the ceilings, what about the returns?

I like to keep them both at the top. It makes sense to put the return at ceiling level, since warm moist air rises, so that's a good place to suck out that stale air and send it either back to the AHU, or dump it overboard.

I'm thinking of running mostly 6" insulated flex duct from the main supply and return trunc in between the walls in to silencer boxes and then out back to flex duct to the vent opening.

Careful with your duct sizing! It's fine to run 6" on the "far" side of your silencer boxes, either inside the wall cavity or outside the outer leaf, but for ducts inside the room you MUST keep the size large enough that the speed is low enough to not create any noise, while still moving the correct volume of air. I try to avoid using ducts inside the room, and just put the registers directly on the ends of the wood "sleeves", that are basically extensions of the silencer box into the room. That allows you build the sleeve with the correct dimensions to keep the flow rate high enough while keeping the slow speed low enough.

1) Does having my HVAC supply trunc running on the floor an issue. (You can see what I mean by last two pics I posted as well as the pictures I posted on the first or second page) The trunc is approx 10" high x 12" wide and currently sitting on 4" of insulation so it's approx. 14" off the floor. I plan to run the return trunc in between the CR and LR wall.

Yes it is an issue, and as I mentioned in my post just above, the easiest way to deal with it is to build a structural box frame over it, with the wall on top. Part of that "box" will extend into the room, and be covered with OSB, MDF, plywood, drywall, etc. The wall will sit on the back edge of that "box", and extend upwards, also supporting the ceiling. So the box is structural (load bearing) as it must support the inner-leaf wall AND the inner-leaf ceiling. At some point you will need to hire a sttructural engineer to take a look at your existing floor, and tell you just how much extra load you can put on it. VERY IMPORTANT! Don't build ANYTHING without having a qualified, certified structural engineer give you his professional opinion in the form of a written report.

2) Can I still do bass trapping at that height with some fancy framing or does the bass trapping need to be done right off the floor?

Yes!

3) I've mentioned that I was thinking/planning on wrapping the main supply and return truncs all around in 4" mineral insulation, Would you say that's a good idea?

Yes, but if you have a noise problem with those, you might also want to wrap them with MLV. This is one place in studios where MLV does have a use that justifies it's high cost. It might or might not be necessary, depending on how much isolation you need.

Cheers from freezing Canada!! lol

Our forecast is for 34° degrees today... CELSIUS! I hear you guys are getting very icy conditions right now, with worse to come. I've been to Canada quite a few times (my sister in law and family live in Ottawa, and I've done business in Toronto and Montreal. I remember being in Montreal right after an ice storm, and they told me it had been down to -60° the week before... It was "only" -30 that week.... I don't know how you guys can even survive in those conditions! Suckers for punishment, I guess! If it goes below -2 or -3 here, that's COOOLLLLDDDD!


- Stuart -

[Studio45]

Symmetry is critical: You must be centered, and the room must be symmetrical about your: left half = mirror image of right half. However, that does NOT mean that the door has to be centered! You can still have the room symmetrical, acoustically, with the door off-center if it has to be off-center for other reasons.

Ok understood!! I need to be centered when in the listening position. I wasn't thinking about having my desk in front of the door/window but I think this would work. I originally thought I had to be all the way up against the front wall but having room in front could work. I guess I should figure out how far back from the front wall I have to be? Like how far away from the speakers? I'll have to dig around to find the recommended distance based on my total room length and the recommended angle the speakers would need to be on.

Absolutely, yes! One door in each leaf, back-to-back, with an air gap between them. And they can both have glass in them, if you want to have good sight lines between the rooms.

Excellent! I think I'll just do that and put glass in both doors. (I guess the thicker the glass the better?) There's a local glass shop nearby and they can custom cut me any size I need.

I like to keep them both at the top. It makes sense to put the return at ceiling level, since warm moist air rises, so that's a good place to suck out that stale air and send it either back to the AHU, or dump it overboard.

Ok I'll keep them both at the top. I might try to design the ceilings so that I can run the ducts on over top.

Yes it is an issue, and as I mentioned in my post just above, the easiest way to deal with it is to build a structural box frame over it, with the wall on top. Part of that "box" will extend into the room, and be covered with OSB, MDF, plywood, drywall, etc. The wall will sit on the back edge of that "box", and extend upwards, also supporting the ceiling. So the box is structural (load bearing) as it must support the inner-leaf wall AND the inner-leaf ceiling. At some point you will need to hire a sttructural engineer to take a look at your existing floor, and tell you just how much extra load you can put on it. VERY IMPORTANT! Don't build ANYTHING without having a qualified, certified structural engineer give you his professional opinion in the form of a written report.

I can frame a load bearing box no problem around the supply trunc. I got that part and love this idea! As you mentioned I'll cover it afterwards with either OSB or 5/8" drywall.

As for the engineer part I've always gotten the okay from him. I got the "official" numbers back from the engineer a few months ago and with my current constructed "timber" floor I'm able to support 33psf of dead load. From what I've been able to calculate I will be fine.

Our forecast is for 34° degrees today... CELSIUS! I hear you guys are getting very icy conditions right now, with worse to come. I've been to Canada quite a few times (my sister in law and family live in Ottawa, and I've done business in Toronto and Montreal. I remember being in Montreal right after an ice storm, and they told me it had been down to -60° the week before... It was "only" -30 that week.... I don't know how you guys can even survive in those conditions! Suckers for punishment, I guess! If it goes below -2 or -3 here, that's COOOLLLLDDDD!

Man 34 degrees would be so nice right about now. It's been in the -20s for a few weeks in a row now. No way I actually live 15minutes from Ottawa!! Small world! Maybe one day you can come visit the studio

-20s are cold but bearable....-30s and -40s are tough to deal with.

Thanks for your help Stuart! Cheers!

Francis,

[Soundman2020]

I originally thought I had to be all the way up against the front wall but having room in front could work.

It's one of those many myths about studios and acoustics....

I guess I should figure out how far back from the front wall I have to be? Like how far away from the speakers? I'll have to dig around to find the recommended distance based on my total room length and the recommended angle the speakers would need to be on.

Forget the famous "equilateral triangle" thing... another myth. Well, partly correct, but not completely.... In fact, it works the other way around: There's a correct location for the mix position, and a correct location for the speakers. When you set up those two, the speaker

angle

works out all by itself! Depending on the room, there's usually a bit of wiggle-room in those locations and angles, and if the speakers will just be on stands (not soffit-mounted), then it pays to actually do the "theoretical perfect" setup, then nudge things around in vary small steps, to see if you can find a better spot, and optimize it.

OK, this is where it gets risky: I'll give you some numbers, but please don't take them as "written in stone"! They are NOT law: just good starting points. Generally when we give out numbers like this, people tend to nail their chair to the floor at that exact spot, then clamp their head in a vice, and never budge a single mm... but that's not it. These are theoretically optimal, but still not necessarily exact for your room, and with a good amount of variability. So: 38% That's the "best" spot, in theory, for the mix position. 38% of the distance from the front wall to the rear wall. That's where your ears should be. But in reality, anywhere between maybe 32% and 44% will likely be fine. So that's where you chair should be: such that your ears end up around 38% from the front wall.

Then, 28%. That's the distance from the side wall. 28% of the distance across the room. But this is even more ephemeral than the 38% one: There's a broad range here, and many factors could shift that... such as for example a slanted ceiling.... ! Or the distance between the speakers... or the angle of the speakers... or if the speaker ends up almost in the corner, or in line with the corner... If those don't work out to sensible numbers, then adjust the speaker location, left or right. But NOT front or back! They must be either tight up against the front wall, or tight up against the front wall! No options here. The rear corner of the speaker must be just 10cm away from the front wall, and that 10cm must have 10cm of insulation in it. This part is fixed: no wiggle room.

And finally: 120cm. That's the height of the ACOUSTIC AXIS of your speakers above the floor. Not the top or bottom of the box, not the woofer or tweeter: the acoustic axis. Check with the manufacturer of your speaker to find out where that is. Your speakers must be set up such that the acoustic axis is at 120cm, or maybe slightly above. Depending on the speaker, it might go up to maybe 130, but seldom higher than that. Why 120cm? Because that's the height of your ears above the floor, when seated! That holds true for the vast majority of people. It might be a couple of cm up or down from there, but it won't be far off.

So that's the basic setup. Start out with that, and you'll be fine, or close to fine.

If you plan to soffit-mount, then the same rules hold true, more or less, but modified for the soffits. That's a whole different ballgame (soffit mounting), so if you do go down that road (very much recommended!) then you'll need to do quite a bit more research on soffits...

(I guess the thicker the glass the better?)

weeellll..... yes, but it's a bit more complicated than that! Your entire studio construction is a tuned, resonant system, and each part needs to be properly calculated to ensure that it is tuned correctly.

There's a local glass shop nearby and they can custom cut me any size I need.

Laminated glass is what you need. Not ordianry window glass. Laminated glass cannot be cut: it is manufactured to the right size. It CAN be cut with specialized gear, but I doubt your local shop has that. They'll have to order it for you.

I'm able to support 33psf of dead load.

That's pretty good.

I actually live 15minutes from Ottawa!! Small world! Maybe one day you can come visit the studio

Cool! I'd like that. It's not too often I get to visit studios that I've been involved in.

- Stuart -

[Studio45]

Hey Stuart!

So I did a bit of work on my plan last night and came across a few things where I need your help.

So: 38% That's the "best" spot, in theory, for the mix position. 38% of the distance from the front wall to the rear wall. That's where your ears should be. But in reality, anywhere between maybe 32% and 44% will likely be fine. So that's where you chair should be: such that your ears end up around 38% from the front wall.

Ok I get that there's a bit of play on those numbers but I'm not sure this would work for my room. Here's a picture showing the 38-44% from the front wall.

Studio-CR-3.0-ListeningPosition.jpg

As you can see with having the door right in front of the desk doesn't allow me to have my ears at that listening position. I just want to confirm a few things related to this:

1) 38-44% number has to be from the front of the actual inner wall and not from the front of the small angled soffit walls or front of the speakers because that would help me a bit but not by much. I've attached a few other pictures to illustrate sort of a layout in the room and things are pretty tight with that door requiring to open from the inside of the CR.

2) One way to get closer to the front wall would be to only use 1 door vs two. Could I still get away with good isolation from using only 1 solid core door from the LR instead? I could add a few layers of MDF to it to make it as massive as possible?

3) If I do go with the single door option and am able to get to the "ideal" number in front of the wall, I'm not sure the soffit mounting idea could be an option as the two angled baffle walls wouldn't allow anyone to enter the room right? This makes me think of flipping the room again but I don't think that would help much since I'd need to do alot of trapping on the rear wall.

This all brings me back to the original plan. I just need to know if you think based on my picture I could get away with being at about 70% from the front wall? Otherwise I might need to work with Speaker stands. haha. Maybe that's something I'd have to compromise with...?

Here's another picture that shows change I made to the CR wall near the window.

Studio-CR-3.0-RearWall-HVAC.jpg

As you suggested I made the wall go behind the HVAC duct and built a small frame around it. If you notice I put in a 3" conduit to run/fish cables. I would cover that box up with something obviously. Do you think this would work? I'm sure I'd be okay to support my ceiling that way. Note there would be a few additions to the wall such as a proper header and double top plates and other things but it would for sure be able to support the ceiling as is.

Here's another picture of a potential layout...kinda tight but I think it could work assuming that all the numbers work out.

Studio-CR-3.0.jpg

Studio-CR-3.0-Top.jpg

[Soundman2020]

As you can see with having the door right in front of the desk doesn't allow me to have my ears at that listening position

solution: Use sliding glass doors, such as the ones I showed in the images above, from the studio in Australia. They do not need any space at all to swing into.

1) 38-44% number has to be from the front of the actual inner wall and not from the front of the small angled soffit walls or front of the speakers

It's actually 32 - 44%, with 38% being the "ideal". The measurement is from the surface of the drywall on your inner-leaf front wall, excluding all treatment, soffits, decorations, etc. It's the hard, solid, rigid, massive boundary surface of the room itself. That's what the modal response is relative to.

2) One way to get closer to the front wall would be to only use 1 door vs two. Could I still get away with good isolation from using only 1 solid core door from the LR instead?

It's possible.... but it depends on how much isolation you need! That's the firet thing you need to define for your studio. A realistic number, in decibels, for how much isolation you need.

3) If I do go with the single door option and am able to get to the "ideal" number in front of the wall, I'm not sure the soffit mounting idea could be an option as the two angled baffle walls wouldn't allow anyone to enter the room right?

For a small room like yours, yes, that might be a problem. But you won't know for sure unless you lay it out in SketchUp!

This makes me think of flipping the room again but I don't think that would help much since I'd need to do alot of trapping on the rear wall.

Flipping it would be an option, yes: in that case, your soffits would be in the space you are gaining from moving that wall back, on top of the "box" over the HVAC. Yes, you would still need a stack of treatment on the rear wall, but it would not interfere with having a door there, like the soffits might.

Here's another picture that shows change I made to the CR wall near the window

You still need a gap between your two walls! You are showing the inner-leaf framing right up against the outer-leaf framing, in direct contact. You need maybe a few cm there. That's why I suggested building a structural box over the ducts, then building the wall ON TOP of that: you didn't do it that way in your current plan. You show the box as butting up against the wall.

One more question: Any chance you can make the room bigger, by moving the wall with the door it it?


- Stuart -

[Studio45]

UPDATED with PICS

solution: Use sliding glass doors, such as the ones I showed in the images above, from the studio in Australia. They do not need any space at all to swing into.

You're right! I could do that and will def consider, but I suppose I need specialized sliding glass doors that would cost thousands of dollars? haha . I want to do the right things as best I can but if I have options that save me some money it would really have to be a must have to achieve what I want. Either way I will consider and choose appropriately.

t's actually 32 - 44%, with 38% being the "ideal". The measurement is from the surface of the drywall on your inner-leaf front wall, excluding all treatment, soffits, decorations, etc. It's the hard, solid, rigid, massive boundary surface of the room itself. That's what the modal response is relative to.

Ok Understood! Thanks!

It's possible.... but it depends on how much isolation you need! That's the firet thing you need to define for your studio. A realistic number, in decibels, for how much isolation you need.

We had previously talked about this at the beginning of my thread and based on the structural limitations of my floor you had mentioned that a realistic isolation level would be around 40db to 50db if sprinkled my studio with pixie dust and that unicorns....nevermind haha. The plan for the floor (not indicated on the plan yet) is a damped deck individually in each of the two rooms. I found a rigid mineral insulation from Roxull that I think could work as well as the OC703 that's often recommended but not super available around here.

For a small room like yours, yes, that might be a problem. But you won't know for sure unless you lay it out in SketchUp!

I had some time to try it out real quick and I have to say I don't hate this design even though I'm not facing the door. This might even work with double doors. Also that desk is pretty big and doesn't need to be that big for me. I'm only using that desk to give me an idea of the space I need overall. Here's the picture with the desk facing the outer wall...

Studio-CR-3.1-Top.jpg

I think this would work for soffit mounted monitors but I would need a rough idea of how big/deep the soffit walls would need to be. I haven't picked any specific monitor speaker yet as I'm exploring options and reading reviews, but considering this will be such a small room, I don't think I'd need anything big and powerful?

Flipping it would be an option, yes: in that case, your soffits would be in the space you are gaining from moving that wall back, on top of the "box" over the HVAC. Yes, you would still need a stack of treatment on the rear wall, but it would not interfere with having a door there, like the soffits might.

Again, going with the picture above, I think this might work better but would need a rough estimate of how thick those traps would need to be on the rear wall.

You still need a gap between your two walls! You are showing the inner-leaf framing right up against the outer-leaf framing, in direct contact. You need maybe a few cm there. That's why I suggested building a structural box over the ducts, then building the wall ON TOP of that: you didn't do it that way in your current plan. You show the box as butting up against the wall.

Sorry Stuart, I guess you can't really see it on the pic but the inner wall is actually 1inch away from the outer wall. Here's a picture to show closer.

Studio-CR-3.1-HVAC supply detail.jpg

There's approx. 1/2" around the HVAC duct so the duct doesn't touch any lumber either. Again I was going to build it the way you explained but just added to what I had already. I'm probably missing something but doesn't just building a regular wall then adding the box to it do the same thing? The only thing that makes me think you want me to build the box first is that I could cover the entire box with MDF/OSB before putting up the wall on top it? Either that's not a problem and an easy fix in Sketchup if that's the case

One more question: Any chance you can make the room bigger, by moving the wall with the door it it?

I'll stretch it as much as I can. Sucks that I have limited options because the entry door to the studio is right down the middle of the outer room. I could try and include the entry door as part of the CR and this would give me a much bigger CR, but if I switch the CR with the it would leave me with smaller LR than the CR which I believe is not recommended.

Oh the joys of planning....haha . Better now than 1/2 way through the build.

[Stadank0]

some pics referencing what Stuart was talking about with objects and openings..

In every case whether a ceiling module of box opening, I would build a perimeter of caulking then remove the excess once the object was in place. It was quite effective.

20160711_222410.jpg

20160714_173741.jpg

20160513_192642.jpg

20160709_153532.jpg

20160415_163155.jpg

I know I'm blowing my horn a bit, but every time I look back at the pics, I'm amazed that I managed the entire interior with zero help..save the mechanical lift of course!

[Studio45]

Wow! That's awesome work man! Makes me want to build something haha.

Those silencers are HUGE!! I assume you built a huge supply and then have 2 outputs in one box?

I decided I will try to build my boxes so that they fit on top of my ceilings. I just don't have any other place to put them. I also have no choice but to put all my supply and return runs in between the LR and CR walls. I'm working on those details now so I'm hoping to post tonight.

Man I wish I had more room to work with. If I didn't care much for my unfinished 1800sq/ft basement I would have used it all up for a studio but I will need the room. lol

About your boxes, I'm having a hard time figuring out how you're decoupling the silencer outputs sticking out of from the ceilings. Is the part that sticks out from the box already decoupled with that sealant/caulk? Registers just go over those openings? I suppose the fact that the boxes are directly mounted on the inner ceiling and doesn't touch any other part makes it decoupled?

Great work!

[Stadank0]

Yeah, the boxes are not decoupled, save the caulking which is acoustic grade...they work great so it doesn't seem to be an issue. The boxes themselves are resting on iso pads.

I ended up having to resize the entire system because my local guy got the sizing of the system wrong at 3 tons. I bought the system and got stuck with it. It really should have been 2. I went with a 14" trunk and resized all of the boxes to suit. It really should have been 16" to suit a 3 ton but I didn't have the space...I did what I could, adjusted the fan speed of the handler to account for static pressure, and crossed my fingers. Its been working with no issues for over a year now...glad that's over!!

1800 sq ft...wow! ceilings too low? Too dark? My whole space is just under 700 sq ft.

This is the stuff I used throughout the studio. I got it for about $6.50/tube and went through about 20 cases of it!! I have to say it really does seem to damp vibrations in joints and connections very well. I really noticed it in the LR when I was building the ceiling soffits. As I installed the first few ribs, I noticed they were very resonant when you banged on them. Boom, boom,boom, like a noisy car stereo that pulls up next to you..lol I took them back out and built everything with this stuff in the joints and got rid of the resonance. Up to that point I had thought of it only in terms of mass because this stuff is pretty dense. I only used this stuff, so I never compards it to regular caulking.

white-osi-sealants-1496542-64_1000.jpg

[Studio45]

1800 sq ft...wow! ceilings too low? Too dark? My whole space is just under 700 sq ft.

Yeah it's a big space with 9' ceilings. We need it for a spare bedroom, full bathroom, home theatre room, mechanical room and workout room. I plan to build a big separated garage at some point but that might be in 5-10 years. Depending on how things go I might move and build an entire new studio as part of the building. For now, I just want to finish this project so I can produce/write music sooner than 10 years haha.

[Stadank0]

word..

[Studio45]

Ok Stuart here's the latest.

solution: Use sliding glass doors, such as the ones I showed in the images above, from the studio in Australia. They do not need any space at all to swing into.

I'm not a big fan of sliding glass doors but if in the end it's the only option I have I will accept it. But I think I've got something that works now. See below...

It's possible.... but it depends on how much isolation you need! That's the first thing you need to define for your studio. A realistic number, in decibels, for how much isolation you need.

Ok, we did had this conversation in previous posts from last year. Due to my studio being above my garage, makes my floor the weakest link of my studio build. This in turn sets a limit of how much isolation can be achieved with my current floor composition. The decision was made to build individual damped deck style floors in the two individual rooms. From this I'm aiming for at least 50db of isolation. Anything more would be icing on the cake, but I'd be perfectly happy being in the 50 range. Based on what you've told me If I do things right I should be able to achieve that.

For a small room like yours, yes, that might be a problem. But you won't know for sure unless you lay it out in SketchUp!

Ok I adjusted my plan and changed the plan back to the original idea of the front wall being the one with the window in it. Here's a pic...

Studio-CR-3.1-Top.jpg

I have to say I don't hate this design even though I'm not facing the door anymore. I think this might even work with double doors. I also think this could work best for flush mounted monitors but I would need a rough idea of how big/deep the soffit walls would need to be. I haven't picked any specific monitor speaker yet as I'm exploring options and reading reviews, but considering this will be such a small room, I don't think I'd need anything big and powerful?

My only concern would be how much space would I require to build traps on the back wall. How thick does the absorption need to be for such a small room? Are there formulas I can use to get a rough estimate?

You still need a gap between your two walls! You are showing the inner-leaf framing right up against the outer-leaf framing, in direct contact. You need maybe a few cm there. That's why I suggested building a structural box over the ducts, then building the wall ON TOP of that: you didn't do it that way in your current plan. You show the box as butting up against the wall.

Sorry Stuart, I guess you couldn't really see it on the pic but the inner wall is actually 1 inch away from the outer wall. Here's a picture to show closer.

Studio-CR-3.1-HVAC supply detail.jpg

About the box; I was going to build it the way you explained but just added to what I had already. I'm probably missing something but doesn't just building a regular wall then adding the box to it do the same thing? The only thing that makes me think you want me to build the box first is that I could cover the entire box with MDF/OSB before putting up the wall on top it? Either that's not a problem and an easy fix in Sketchup if that's the case

One more question: Any chance you can make the room bigger, by moving the wall with the door it it?

I've adjusted the plan already and I've stretched the CR as much as I can. Sucks that I have limited options because the entry door to the studio is right down the middle of the outer room. I could try and include the entry door as part of the CR and this would give me a much bigger CR, but if I switch the CR with the it would leave me with smaller LR than the CR which I believe is not recommended.?

About the baffle/silencer boxes, I've decided I will put them above the ceiling of each room. This will give me some extra space for the CR and LR all together by not having 16" of space between the CR and LR wall. This though would use up a bit more room for total ceiling height but I think I could still get around 8.5ft total.

Ok HVAC talk....
I'm currently trying to size everything up for my HVAC design as I want to know exactly what I can fit in between the walls of the CR and LR. I have already purchased a AHU that is sized for the room and then some. (800cfm / 3-speed). I've done a few calculations that I know I need to use in order to size everything up. For example, I've calculated the Room CFM requirments by using the following formula.

From what I was able to gather from other posts and research online, the size and type of room would require 6-8 air changes per hour?
The approx. volume of the room is 3450cf (this is for the entire room and not individual). 3450 * 6 changes per hour = 20700/ 60minutes per hour gives me 345 CFM.
For heating and cooling requirements the size of the total room requires 14,000BTU of both heating and cooling. Heating I know can vary based on climate and such but my unit is capable of max 56,700BTU at 800cfm so I'm sure I'll be fine with this unit.

I'm trying to figure out if I can get away with having one supply and one return duct per room or would I need 2 or 3?. How can I figure that out based on all these numbers? I've read that for rooms 100 sq/ft and bigger should have 2 to 3 registers.

Oh the joys of planning....haha . Better now than 1/2 way through the build.

[Gregwor]

Great work on the planning stage!

Where will your AHU live?

Can you build some soffit/front/side walls in sketchup just so we can see how they will fit? Build a rectangle and pull it up even... no need to build it stud for stud just to see how it looks.

Regarding speakers for your soffits, I've looked into the Barefoot MicroMain 45's and speaking with Thomas, he says they should work well with a low shelf circuit inline (which he also sent me design for). Just food for thought because Barefoot rule.

About how many registers you need in your rooms, know that whatever you calculate for your supply duct lines, you'll need double the cross sectional area of that for both the interior of your duct silencer boxes as well as their outlets.... all the way to the registers. So, say you have an 8" round duct from your AHU, your box would have 8" round in and either two 8" round out or a rectangular opening with the same cross sectional area of two 8" round ducts. These would then maintain that size (internally) all the way to your registers that also have to be able to maintain that size or bigger. Sadly, all of this = lots of real estate in your space.

I suppose it all comes back to where your AHU will be and where you'll be able to have it penetrate into your space. From there, you can decide where you can afford to lose the space for the silencers.

Greg

[Studio45]

Thanks Greg! It's a great learning experience so I don't mind taking more time and paying a bit more attention to details. I will admit that I'm very eager to start actually building something lol!

Where will your AHU live?

Here are a few pictures that show where the AHU will be. It's basically a small HVAC closet and it is part of the house so will be well isolated from the studio itself. I also have a picture that shows the supply and return ducts running in between the CR and LR walls. I've added some ceilings to show the room/area where I could put the silencers over.

Studio-HVAC-Details1.jpg

Studio-HVAC-Details2.jpg

Studio-HVAC Closet.jpg

Studio-HVAC Closet-2.jpg

Here's the storage area on the other side of the entrance door of the studio.

Studio-StorageArea.jpg

Regarding speakers for your soffits, I've looked into the Barefoot MicroMain 45's and speaking with Thomas, he says they should work well with a low shelf circuit inline (which he also sent me design for). Just food for thought because Barefoot rule.

Thanks! I will def look into this!

Can you build some soffit/front/side walls in sketchup just so we can see how they will fit? Build a rectangle and pull it up even... no need to build it stud for stud just to see how it looks.

Sorry I'm not quite sure what you're referring to here? You mean the actual Speaker Soffits? Once I get confirmation that my framing is ok and will work this way I'll add more details and start figuring out the placement of the soffits and speakers.

About how many registers you need in your rooms, know that whatever you calculate for your supply duct lines, you'll need double the cross sectional area of that for both the interior of your duct silencer boxes as well as their outlets.... all the way to the registers. So, say you have an 8" round duct from your AHU, your box would have 8" round in and either two 8" round out or a rectangular opening with the same cross sectional area of two 8" round ducts. These would then maintain that size (internally) all the way to your registers that also have to be able to maintain that size or bigger. Sadly, all of this = lots of real estate in your space.

Thanks for the tip! This is something I'm currently reading up on and am playing close attention to.
I'm trying to figure out if I can get away with using one single 6" flex duct per room and running the that to the silencer box which would have two outputs. I'd have a total of four big silencer boxes. I'm working on the math so I'll find out soon enough. I'm def seeing the use of space a HVAC system takes....but understand that it's probably the most important thing since it provides fresh air haha.

[Studio45]

Hey everyone, I was able to get a few additional details done on my plan. Mostly visualize my HVAC system and figure out sizing and silencer boxes. I've added the 2 x 5/8" drywall to most walls of the studio to give it a better look. I haven't put the roxul insulation inbetween all the studs but will do at some point. I really like the idea of putting the silencer boxes on top of each rooms and feel it will be my best option to save space below.

I'll post updated pics shortly as I still have to make some final adjustments to the model.

Here are a few numbers and details of the HVAC system that I was able to determine.

Required CFM of each room
CR - 142.5cfm
LR - 185cfm

Using branches of 8" round metal ducts all the way to the silencer boxes would work well. I would split the silencer boxes and have two outputs for each to reduce the velocity of the air coming out.
With a 8" duct I should get an approx. duct velocity of 408FPM for the Control Room and 531FPM for the Live Room, just before entering the silencer box. This should give me some decent numbers in the end as I hear anything below 300FPM is good?

For my fresh air supply, I plan on grabbing this air from outside of my studio and from inside my home, more specifically from the staircase leader to the studio. I have a separate HRV system that takes care of this already for my entire house. Based on what I was able to gather from other builds, etc...If I run a 6" duct with a dampener, from inside my house to my return trunc just before the fan this should work. Do you see anything wrong with this? I've seen multiple installations with just a 6" duct sticking out just before the filter on the return trunc.

Stuart, if you read this, I'm wondering if you could confirm if there's something wrong with the way I build the frame around my supply trunc. (see my previous post). I was going to build it the way you explained but just added to what I had already. I'm probably missing something but doesn't just building a regular wall then adding the box to it do the same thing? The only thing that makes me think you want me to build the box first is that I could cover the entire box with MDF/OSB before putting up the wall on top it? Either that's not a problem just need to know if that's the case.

Stay tunned for more! I'm going to work on the HVAC closet and storage area.