John Sayers' Recording Studio Design Forum Archive

Hello again Jag94,

I explained that I hired a SE for a couple of reasons (I don't blame you for not reading that insanely long first post).

My mistake - I usually devote more time to reading threads & researching relevant info but (as per my disclaimer) I'm knee deep in my build at the moment & my recent experience on the forum is that most members won't acknowledge a reply, so I have decided to scale my efforts accordingly.

I hired a SE for a couple of reasons

As far as cutting up drywall and putting in between the slats - kill me now.

I feel your pain dude - I have recently cut 36 panels out of cement board, all mounted on their own individual softwood frame, fitted in between the rafters of my garage and none of them were identical dimensions. I need to add the same number of OSB panels next week and it's painstaking work. Now I think about it, nobody said it would be a picnick!!

Cutting the foam is a pain in the ass . . . I just started to think if it was really necessary

I understand your dilemma - the one lesson I've learned from this whole process is that studio design is a succession of compromises. My view is that you are doing the right thing by completely filling the gap; if it wasn't a pain in the arse, then everyone would be doing it! Looking forward to hearing more about your project. ATB John.

My mistake - I usually devote more time to reading threads & researching relevant info but (as per my disclaimer) I'm knee deep in my build at the moment & my recent experience on the forum is that most members won't acknowledge a reply, so I have decided to scale my efforts accordingly.

I apologize if my reply came across the wrong way, I didn't mean to be crass. I am sincerely thankful for anyone who takes the time to reply as obviously everyone has their own stuff happening.

I feel your pain dude - I have recently cut 36 panels out of cement board, all mounted on their own individual softwood frame, fitted in between the rafters of my garage and none of them were identical dimensions. I need to add the same number of OSB panels next week and it's painstaking work. Now I think about it, nobody said it would be a picknick!!

No they didn't. And I knew that. But HOW painstaking I didn't know. But I value the experience of getting my hands dirty doing the work myself, as I'm sure you do as well. Having to cut each of those panels and them all being different dimensions is hellish work. I did the same with my OSB in between the studs. It's not fun.

I understand your dilemma - the one lesson I've learned from this whole process is that studio design is a succession of compromises. My view is that you are doing the right thing by completely filling the gap; if it wasn't a pain in the arse, then everyone would be doing it! Looking forward to hearing more about your project. ATB John.

Yeah, Rod mentions it several times in the book, and I'm starting to really understand it. I guess I'll just keep trucking along. Thanks again for checking in.

Little update here.

I've decided to go with a hot roof even though it is causing me to go several thousand dollars over budget, but I was able to negotiate the price since I'll be doing some of the work myself, and I already have some of the materials.

I'm filling the gaps in between the slats on the underside of the roof with 1" EPS foam. I'm using expanding spray foam to fill any gaps that I can't get the foam into. It's time consuming, but I think it's worth it.
Next is to start building the large gussets that will attach to the rafters. I'll post more details about this when it's done.

While this is happening, I've been thinking a lot about HVAC and electrical. I feel like I have an above average understanding of what I want and need to do with the electrical, but I do have some questions I'll get to as I progress with the project.

As far as HVAC, here is what I WANT to do.

I already have a ductless mini split system that I will be using to heat/cool the room. As far as ventilation, this is where I'm a little stuck. The garage is small. When I build the room inside the room, it is taking significant square footage away, especially since I'll be lowering the ceiling (it will no longer be a cathedral ceiling, even thought that's what I would prefer). The total cubic footage will be around 1900 cubic feet. Actually a little less. I don't have a separate room to house a full size ERV unit, and then run ducts to and from it. So I need to find a unit that can be installed inside the room, and have the ducts go to baffle boxes inside the room, into the wall space, and then exit the exterior with outdoor baffle boxes for the outer leaf.

There are basically two products I'm looking at, and both of them say they are rated for room ventilation for spaces up to like 1,700 sqft. Now notice that's sqft and not cubic feet. But I don't know if the specs on these units takes into account how many people are in the room. One unit can do a maximum of 40cfm, the other 75cfm. Is the CFM rating more important than the size of the room rating? I will be using this space MOST of the time with just me in it. Probably 90%-95% of the time. The other 5%-10% will have anywhere from 2-5 people in there. So I'm assuming the unit that can handle 70cfm is probably the way to go.

Is there another way I should be thinking about this?

Is there a recourse for learning how to build a frame? I understand the concepts and know how to build a single wall, how to cut rafters, frame a door, and some other basic aspects, but I'm looking for a more in depth tutorial. Something that will cover everything, putting it all together. That would include proper connectors, how to frame a gable end wall, how to make sure the frame is strong enough for the mass I want to put on it, etc. I've been google searching and watching a lot of youtube videos, but since it's a single room, I'm getting a lot of "how to build a shed" or "how to build a shed roof" kind of stuff. I'm looking for a more comprehensive recourse. Any books anyone can recommend?

Ok so after a bit more research, and re-reading Rod's book, I feel like I have a LITTLE better understanding of the HVAC situation. HVAC is complicated. Here's what I have so far.

Estimated dimensions of finished interior room:
15' 3" x 14' 3" x 8' 6"
approx 1800 cubic feet.

With an ideal 6 room changes per hour, that's approx 10.700 cubic feet per hour. Most everything is categorized in cubic feet per minute (not hour), so divide that number by 60, and you get...

10,700/60 = ~178 CFM

The Ductless Mini-Split I will be using has these specs:
High speed - 294 CFM
Medium speed - 212 CFM
Low Speed - 147 CFM

So the split system will be able to heat/cool the room adequately.

To make sure I'm getting enough fresh air into the room, I need 1/4 to 1/2 of the room circulation rate. 40% is a good number to use to estimate.

So 178 x 40% = ~71 CFM

The HRV I want to use has these specs:
High speed - 71 CFM
Medium speed - 53 CFM
Low speed - 35 CFM.

So far we are looking good.

Here's the situation I'm inI will be using this HRV unit.

HRV UNIT

This unit is designed to be installed INSIDE the room. The incoming air and exhaust vents are on the unit itself. It has two 5" ducts on the back that are supposed to go straight through the wall (using duct extenders) and brought straight outside. Obviously this will not work for sound isolation.

I have been reading and re-reading this post by @gregwor (6th post down with the Duct charts). GREGWOR'S POST

I will be putting the two baffle boxes inside the room. I am aware that they can be quite huge, but that's OK. It's my only option, and well, that's how it goes. I plan on making them pretty beefy too, 3/4" OSB, and 2 layers of drywall (same as my inner walls).

I have 3 goals.

1) Make sure I'm getting fresh air in the room, and stale air is being brought out.
2) Make sure the air is conditioned properly.
3) make sure my drumming does not get out of the building through the ducts.

I DO NOT care about the HRV/Mini-Split system noises inside the room. 80% of the time it is just going to be me in the room practicing. 10% will be me recording, 5% will be full band rehearsals, and 5%... well, I don't know yet. But when I am recording, it is most likely going to be just me, so if I need to turn down or turn off the systems to eliminate the noise for 5-10 minutes at a time, I'm perfectly fine doing this. And in all likelihood, the noise won't be enough to bother me during recording anyway.

here is a sketchup of my idea. It is a VERY rough sketch, but just enough to give you an idea. The HRV will be on the wall to the left of the mini-split. The fresh air vent on the HRV is on the right side, so that air will hit the mini-split immediately after leaving the vent. Both ducts will go down and enter the baffle boxes. The boxes will hit the south wall and the air will be brought outside via ducts inside the south wall.
I just need help figuring out how big these silencer boxes need to be, and how big of ducts I need to use inside the wall.



This post was edited with updated information.

Update on recent progress.

I sealed the sill plate (bottom plate) on the exterior frame. I used DAP 230 caulk, and then put Wigluv seal tape over it. There will be absolutely zero air, water, bugs, sound getting through the exterior frame.
The garage door is completely sealed from the inside and out. I caulked (maybe over-caulked?) every possible spot on the inside of the door, and then did the same on the outside of the door. I will be applying THIS "sound deadening" paint onto the interior.
Once that's on, I'll put EPS foam into the panels of the garage, and then build a wall to push right up against it, to create a complete, very mass heavy outer leaf. I'll post pictures as I complete each step.

I also added 2 layers of 5/8" drywall to the inside of the roof overhangs. The exterior is almost complete. Once the garage door is done, I can finally build the interior frame. It's getting close.

Progress Update:

I coated the door with the second skin paint stuff. I did two coats, and the second coat was really thick, as that is what the manufacturer recommends. I used a spray gun, and it went on pretty easily. It's a very strange consistency though.
I knocked on the door before and after putting the paint on, and it definitely lowered the vibration of the door.

I cut up the EPS foam to the correct sizes to fit in the panels of the door, but I'm waiting for the paint to completely cure before I put the foam into the panels. The manufacturer says it will take 7-14 days, so it's kind of good I'm going on vacation for 10 days.

I also built the frame of the wall that will be up against the door.
I just need to put the OSB on it before it gets lifted up and into place, then I need to cut the drywall to put in the bays. After that, I can finally start building the inner frame.

I'm still researching ways to make the HVAC system work. I'm wondering if I can have the HRV unit penetrate the inner wall, and add mass to the other side of the frame to make a large cavity for the air to flow through. Basically turning the bays of the frame the silencer. But I'm not sure this will work.

Ok so some build updates, design concepts, and some questions.

I stuffed the bays of the garage door with EPS foam so that when I stand the wall up, the OSB on the "inside-out" wall will touch directly against the door/foam. There will be no gaps, and it will be one continuous, sealed mass leaf. I attached the OSB to the frame, and with the help of some friends, we stood it up, and I secured it in place. Next up will be adding mass to the stud bays, then caulking the shit out of the perimeter and the drywall in the bays.
Thinking a LOT more about the ERV situation, I started putting down on paper (or in this case, sketchup) how this would work/look. I'm not crazy about it because it's going to take up significant space in the room, but I am concerned with making sure I'm getting adequate fresh air in the room when I have 3+ people in there playing music, sweating, breathing hard, etc... as anyone should be. So here's what I'm thinking.

There are two ERV units that meet my needed specs. This one and This One

The first one is pretty small in dimensions and is much more affordable. It's marketed as an AEV (Air Exchange Ventilator), and by the descriptions, it seems to function much like an ERV or HRV, but for some reason doesn't have the same name. The second one is really slim (albeit longer and wider), so it would sit very high up on the ceiling, effectively not taking up much space at all. It is double the price, but it seems to be a good option. I understand Fantech is a good brand, so I probably can't go wrong with either one.

I will put the unit up towards the ceiling as high as I can on the north wall (which is where the garage door is, and where that new wall was built and stood up). The mini split will be on the west wall, and i'll have the fresh air duct feed the air right into the path of the mini split so it gets cooled/heated immediately. The exhaust duct will run along the perimeter of the room so that it's opening is on the opposite side of the room from the fresh air inlet. I imagine this will help make sure the air in the whole room is being adequately exchanged. I can build the silencer boxes so the supply and return ducts from the unit go directly into them, and then they penetrate the wall and take the air outside. This is how I imagine in. Please excuse the crude drawing of it. It's not exactly to scale, but you get the idea.

I am thinking about possibly building the silencer boxes inside the wall, instead of inside the room. This would help maintain real estate in the room. What are your guys' thoughts?

I also don't know how I'll run the ducting inside the room. I don't want it to look like shit, so I'm hoping maybe I can make it look "industrial", while not completely killing the acoustics in the room. I don't have space above the ceiling to run the ducts, so they have to be run inside the room. any thoughts/ideas/examples of how running a duct in the room could look/work?

I am about to build the interior frame, and as soon as I do, electrical and HVAC will need to be figured out so I can make sure I plan everything accordingly for when it's time to put up the OSB and drywall. I am planning on running a star grounding system with isolated ground receptacles. I have done a TON of research on how to do this, but I wanted to put it down on paper to run it by everyone to see if it makes sense, and is correct.

Right now I have a 200 amp main panel for the house. There is a ground rod right at the main panel, and another one at the front of the house bonded to the water pipes. Currently there is a 40amp sub panel in the garage, that is fed by 10ga wires in conduit underground. There are 2 hots, 1 neutral, and 1 ground wire. I want to turn this into a 60 amp sub panel, so I'm going to swap the 10ga wires with 6ga wires, and put a 60 amp breaker in the main panel. The only electrical penetration through my interior leaf will be the main power. I will be face mounting all outlets, switches, lights, etc to the drywall, all connected by conduit. As far as the star grounding system goes, I understand that each one of my IG receptacles needs to have a hot, neutral, and insulated ground. Each insulated ground will make a home run to a separate ground bus bar, that will then run all the way back to the main panels ground bus, but never touching the equipment ground bus (or ground conductors) in the sub panel. All the outlet boxes will be metal, and will be connected with EMT conduit, so that will act as the equipment ground for each IG receptacle. So this means I will need to run a 5th conductor (the isolated ground wire) through the conduit back to the main panel. These isolated ground receptacles (I'm thinking about 7 total) will be for audio gear only. I will have regular outlets and circuits for other things like lights, AC, refrigerator, etc.

Do I have this right? A diagram would probably be easier to understand. But with everything I've read and seen, this seems to be the correct way to do this. Anything I'm forgetting or should be aware of?

Jag94 wrote:Ok so some build updates, design concepts, and some questions.

I stuffed the bays of the garage door with EPS foam so that when I stand the wall up, the OSB on the "inside-out" wall will touch directly against the door/foam. There will be no gaps, and it will be one continuous, sealed mass leaf. I attached the OSB to the frame, and with the help of some friends, we stood it up, and I secured it in place. Next up will be adding mass to the stud bays, then caulking the shit out of the perimeter and the drywall in the bays.

IMG_3145 small.jpeg

IMG_3146 small.jpeg

IMG_3395 small.jpeg

Thinking a LOT more about the ERV situation, I started putting down on paper (or in this case, sketchup) how this would work/look. I'm not crazy about it because it's going to take up significant space in the room, but I am concerned with making sure I'm getting adequate fresh air in the room when I have 3+ people in there playing music, sweating, breathing hard, etc... as anyone should be. So here's what I'm thinking.

There are two ERV units that meet my needed specs. This one and This One

The first one is pretty small in dimensions and is much more affordable. It's marketed as an AEV (Air Exchange Ventilator), and by the descriptions, it seems to function much like an ERV or HRV, but for some reason doesn't have the same name. The second one is really slim (albeit longer and wider), so it would sit very high up on the ceiling, effectively not taking up much space at all. It is double the price, but it seems to be a good option. I understand Fantech is a good brand, so I probably can't go wrong with either one.

I will put the unit up towards the ceiling as high as I can on the north wall (which is where the garage door is, and where that new wall was built and stood up). The mini split will be on the west wall, and i'll have the fresh air duct feed the air right into the path of the mini split so it gets cooled/heated immediately. The exhaust duct will run along the perimeter of the room so that it's opening is on the opposite side of the room from the fresh air inlet. I imagine this will help make sure the air in the whole room is being adequately exchanged. I can build the silencer boxes so the supply and return ducts from the unit go directly into them, and then they penetrate the wall and take the air outside. This is how I imagine in. Please excuse the crude drawing of it. It's not exactly to scale, but you get the idea.

ERV1 small.jpeg

ERV2 small.jpeg

ERV3 small.jpeg

ERV4 small.jpeg

I am thinking about possibly building the silencer boxes inside the wall, instead of inside the room. This would help maintain real estate in the room. What are your guys' thoughts?

I also don't know how I'll run the ducting inside the room. I don't want it to look like shit, so I'm hoping maybe I can make it look "industrial", while not completely killing the acoustics in the room. I don't have space above the ceiling to run the ducts, so they have to be run inside the room. any thoughts/ideas/examples of how running a duct in the room could look/work?

I am about to build the interior frame, and as soon as I do, electrical and HVAC will need to be figured out so I can make sure I plan everything accordingly for when it's time to put up the OSB and drywall. I am planning on running a star grounding system with isolated ground receptacles. I have done a TON of research on how to do this, but I wanted to put it down on paper to run it by everyone to see if it makes sense, and is correct.

Right now I have a 200 amp main panel for the house. There is a ground rod right at the main panel, and another one at the front of the house bonded to the water pipes. Currently there is a 40amp sub panel in the garage, that is fed by 10ga wires in conduit underground. There are 2 hots, 1 neutral, and 1 ground wire. I want to turn this into a 60 amp sub panel, so I'm going to swap the 10ga wires with 6ga wires, and put a 60 amp breaker in the main panel. The only electrical penetration through my interior leaf will be the main power. I will be face mounting all outlets, switches, lights, etc to the drywall, all connected by conduit. As far as the star grounding system goes, I understand that each one of my IG receptacles needs to have a hot, neutral, and insulated ground. Each insulated ground will make a home run to a separate ground bus bar, that will then run all the way back to the main panels ground bus, but never touching the equipment ground bus (or ground conductors) in the sub panel. All the outlet boxes will be metal, and will be connected with EMT conduit, so that will act as the equipment ground for each IG receptacle. So this means I will need to run a 5th conductor (the isolated ground wire) through the conduit back to the main panel. These isolated ground receptacles (I'm thinking about 7 total) will be for audio gear only. I will have regular outlets and circuits for other things like lights, AC, refrigerator, etc.

Do I have this right? A diagram would probably be easier to understand. But with everything I've read and seen, this seems to be the correct way to do this. Anything I'm forgetting or should be aware of?

Won't the noise from the HRV be a major issue? Or are you not bothered by that?

You can build soffits which double as bass traps running around the ceiling/wall junction which conceal your ducting, into which you can also put down lights if you wish.

Paul

Paulus87 wrote:
Won't the noise from the HRV be a major issue? Or are you not bothered by that?

You can build soffits which double as bass traps running around the ceiling/wall junction which conceal your ducting, into which you can also put down lights if you wish.

Paul

Hi Paul,

It is an issue, but not a big one. 90% of the time in the room I will be practicing (drums), or having full band rehearsals. So the noise from the machine won't even be noticeable or an issue. It's more important that I keep adequate fresh air pumping into the room when there are 5 musicians sweating/breathing hard. When I'm recording, the large majority of the time it's just me in the room. So if I have to turn down, or even turn the unit completely off when recording to get rid of potential noise getting into the recording, I have no problems doing that.

How would the soffits work? would they be completely enclosed? Would that create a 3rd leaf situation? Do you have any examples of how it would look?

Jag94 wrote:

Paulus87 wrote:
Won't the noise from the HRV be a major issue? Or are you not bothered by that?

You can build soffits which double as bass traps running around the ceiling/wall junction which conceal your ducting, into which you can also put down lights if you wish.

Paul

Hi Paul,

It is an issue, but not a big one. 90% of the time in the room I will be practicing (drums), or having full band rehearsals. So the noise from the machine won't even be noticeable or an issue. It's more important that I keep adequate fresh air pumping into the room when there are 5 musicians sweating/breathing hard. When I'm recording, the large majority of the time it's just me in the room. So if I have to turn down, or even turn the unit completely off when recording to get rid of potential noise getting into the recording, I have no problems doing that.

How would the soffits work? would they be completely enclosed? Would that create a 3rd leaf situation? Do you have any examples of how it would look?

I see, and there's no way you could build a small enclosure external to your studio for the HRV? or in another room somewhere? I'm sure you've thought of that but if it's do-able then why not...

One other observation, ideally you'll need silencer boxes for your outer leaf as well.

The soffits I'm talking about are not enclosed, they're basically long bass traps (wooden frames filled with insulation and covered in fabric, yes really that simple) between the ceiling and walls. So, no, no triple leaf effect and actually improved room decay since they will attenuate low frequency resonances. You can check out my thread for the ones I built. This is how a lot of pro designers seem to do it, bury the ducting inside treatment and make it a feature. Just google rooms by Wes Lachot, Francis Manzella, Northward acoustics, Malvicino etc etc

Paul

I see, and there's no way you could build a small enclosure external to your studio for the HRV? or in another room somewhere? I'm sure you've thought of that but if it's do-able then why not...

Yeah the room is really small, and it's a detached garage. I have no other room, to put the unit. I really wanted a smaller HRV/ERV that I could fit in the room without ducting, but the inlet and exhaust was on the unit itself, and are located about 20" from each other. I'm worried that the fresh air that comes out one side will be immediately sucked into the exhaust, which would not really help refresh the air in the room. So this is what I have to do. There is a good amount of space between the inner leaf and outer leaf on the North wall (where the garage door is/was, so I was thinking of figuring out how to mount the silencers in that space between those leafs to save real estate inside the room. But I haven't quite figure out how to do that.

One other observation, ideally you'll need silencer boxes for your outer leaf as well.

I won't be able mount them on the outside of the outer leaf. So unless I'm able to mount them on the inside of the outer leaf, I'll just have to make due with larger ones inside the room.

The soffits I'm talking about are not enclosed, they're basically long bass traps (wooden frames filled with insulation and covered in fabric, yes really that simple) between the ceiling and walls. So, no, no triple leaf effect and actually improved room decay since they will attenuate low frequency resonances. You can check out my thread for the ones I built. This is how a lot of pro designers seem to do it, bury the ducting inside treatment and make it a feature. Just google rooms by Wes Lachot, Francis Manzella, Northward acoustics, Malvicino etc etc

Paul

Cool, I'll check those out. The corners where the walls meet the ceiling on the east/west walls will not be a 90 degree. The ceiling will be slanted for about 2 feet until the ceiling levels off and is flat the rest of the way. So i'll check out some of rooms you mentioned and see if any of them are similar to mine. Thanks for taking the time to bounce ideas off of.

Any thoughts on the electrical concerns I posted?

Thanks

Jag94 wrote:

I see, and there's no way you could build a small enclosure external to your studio for the HRV? or in another room somewhere? I'm sure you've thought of that but if it's do-able then why not...

Yeah the room is really small, and it's a detached garage. I have no other room, to put the unit. I really wanted a smaller HRV/ERV that I could fit in the room without ducting, but the inlet and exhaust was on the unit itself, and are located about 20" from each other. I'm worried that the fresh air that comes out one side will be immediately sucked into the exhaust, which would not really help refresh the air in the room. So this is what I have to do. There is a good amount of space between the inner leaf and outer leaf on the North wall (where the garage door is/was, so I was thinking of figuring out how to mount the silencers in that space between those leafs to save real estate inside the room. But I haven't quite figure out how to do that.

One other observation, ideally you'll need silencer boxes for your outer leaf as well.

I won't be able mount them on the outside of the outer leaf. So unless I'm able to mount them on the inside of the outer leaf, I'll just have to make due with larger ones inside the room.

The soffits I'm talking about are not enclosed, they're basically long bass traps (wooden frames filled with insulation and covered in fabric, yes really that simple) between the ceiling and walls. So, no, no triple leaf effect and actually improved room decay since they will attenuate low frequency resonances. You can check out my thread for the ones I built. This is how a lot of pro designers seem to do it, bury the ducting inside treatment and make it a feature. Just google rooms by Wes Lachot, Francis Manzella, Northward acoustics, Malvicino etc etc

Paul

Cool, I'll check those out. The corners where the walls meet the ceiling on the east/west walls will not be a 90 degree. The ceiling will be slanted for about 2 feet until the ceiling levels off and is flat the rest of the way. So i'll check out some of rooms you mentioned and see if any of them are similar to mine. Thanks for taking the time to bounce ideas off of.

Any thoughts on the electrical concerns I posted?

Thanks

Is there a reason you cannot mount your silencers on the outside of the outer leaf? and again, is there a reason why you cannot build an external enclosure for your HRV so it can also be mounted on the outside of your outer leaf?

Where the ceiling is slanted is still fine for soffits, no difference really whether the ceiling is flat or slanted.

I'm not an electrician so I'll leave that advice to someone else.

Paul

Paulus87 wrote:
Is there a reason you cannot mount your silencers on the outside of the outer leaf? and again, is there a reason why you cannot build an external enclosure for your HRV so it can also be mounted on the outside of your outer leaf?


Paul

It's a detached garage, and 2 sides are on the property line, so I can't install anything on those two sides. The other two sides are the front of the garage which faces the street, and the other side faces the yard. Where I live, I can't put anything on the front that faces the street because the city has rules about changing the "curb appeal" because it's a 'historic district'. And then there is an even higher authority that doesn't want any "additions" on the side of the garage that faces the yard... and that's my wife.

Jag94 wrote:

Paulus87 wrote:
Is there a reason you cannot mount your silencers on the outside of the outer leaf? and again, is there a reason why you cannot build an external enclosure for your HRV so it can also be mounted on the outside of your outer leaf?


Paul

It's a detached garage, and 2 sides are on the property line, so I can't install anything on those two sides. The other two sides are the front of the garage which faces the street, and the other side faces the yard. Where I live, I can't put anything on the front that faces the street because the city has rules about changing the "curb appeal" because it's a 'historic district'. And then there is an even higher authority that doesn't want any "additions" on the side of the garage that faces the yard... and that's my wife.

Understood, say no more