John Sayers' Recording Studio Design Forum Archive

I have many questions before I start writing checks wonder if you could give me some direction.

I'm wanting and STC greater than 70 in my control room and the Is0 2 room . so I can play with out disturbing my family , and keep noise out of the recordings. even record drums in ISO2 .

With the space I have , using double wall construction this is a floor plan I think that might work for me , trading some space for hopefully a couple of rooms that will have and STC of 70+

Looking at clips and channel on the ceiling also adding some mass ( 2*5/8 with GG and rock wool) to the floor above between the joist and using screws to tighten up the hardwood and sub floor layers, will add some MLV and padded engineered flooring at some future point on the floor above .


Double wall construction with 2x 5/8 on the interior walls with GG, sound batting ( safe n sound rock wool ) and 1 layer of 5/8 on the exterior wall.


Other Considerations


Still trying to debate the thought of adding a split mini for the AC rather than mufflers on my existing HVAC which I had sized for the whole house ( 4.5 ton unit) including coold the garage thats being ocnverted. There's probably enough space in the adjacent hall way to build and to penetrate studio walls with mufflered returns and registers , but the split mini idea is starting to really appeal to me . It would also address a problem we've been having , a two story house with one thermostat , I'm usually freezing year round if my wife has her preferred temperature upstairs .

Stop me now if you see some mistakes in the works..


And help would be very welcome .

Thank you

Welcome clearvoice (whatever your real name is)!

Please read the Forum Rules as you are missing some required information in your profile! The forum is very strict about these rules.

I'm wanting and STC greater than 70 in my control room and the Is0 2 room . so I can play with out disturbing my family , and keep noise out of the recordings. even record drums in ISO2 .

I'll start by suggesting that you spend a few solid days, or weeks reading some threads on the forum and you'll see that the answers you seek, plus a TON more information, is all here. The forum is a great source for people like you and I that are trying to design and build our dream studies in our homes and even commercial locations.

Having said that, it is said again and again on the forum that STC is not the proper measurement for full range instruments. You'll also see on the forum that achieving 70dB of isolation is VERY hard to do without going to extremes and spending hundreds of thousands of dollars. Upwards of 60 is achievable with careful planning and very careful building. If you use the search feature on the forum, type in STC and I'm confident that one of the first results will show a big rant done by Stuart (Soundman2020) explaining in detail why STC is not valid in recording studio design.

the Is0 2 room

Where is ISO room #1?

With the space I have , using double wall construction this is a floor plan I think that might work for me , trading some space for hopefully a couple of rooms that will have and STC of 70+

You're obviously wanting to contain the energy of a drum kit from the rest of the house. That means you NEED to use MSM construction. So yes, "double wall construction". The floor plan looks almost decent considering what you have to work with. However, do you NEED a lounge? Are you going to have lots of people over during recording sessions that you need to occupy and keep out of the control room during tracking sessions? If not, I'd highly recommend using that space for your tracking room. Bigger always = better in recording spaces. Again, I will say that STC means nothing here. And basically, you should shoot for as much isolation as you can afford both space wise and financially if you want to record drums without disturbing neighbours or your family/room mates.

Looking at clips and channel on the ceiling

Nope. Clips and channel on the ceiling will not provide enough isolation in the problematic low frequencies for the level of isolation you've described. You'll need to build a full MSM system. That means resting LVL studs across your inner leaf walls. This will allow your ceiling to not touch the rest of the house (the outer leaf) at all except via the walls to the concrete slab on which they rest. Earth is a good enough damper to provide great isolation.

also adding some mass ( 2*5/8 with GG and rock wool) to the floor above between the joist and using screws to tighten up the hardwood and sub floor layers, will add some MLV and padded engineered flooring at some future point on the floor above .

Yes. You WILL have to add that mass to the floor above, from below using cleats to hold the 5/8" + Green Glue against the existing sub floor above. NOT screws. You can do the math to figure out if you need the extra mass above. But remember, MLV is VERY expensive and you would have to get an engineers stamp to add that kind of mass to the floor. Already, adding two layers of 5/8" drywall to the underside of that floor might be maxing the floors load limit.

Double wall construction with 2x 5/8 on the interior walls with GG, sound batting ( safe n sound rock wool ) and 1 layer of 5/8 on the exterior wall.

You didn't tell us what the exterior wall is made of. Most homes where I live are sheathed with 3/8" OSB. So, adding only 1 layer of 5/8" drywall to it might not be enough. Again, you're going to have to do the math to figure out how much mass (and gap) you need to achieve your required transmission loss levels. Here is a transmission loss excel spreadsheet I threw together. Read the comments/notes on the right of sheet 1. You can change values to match your construction and then the second sheet will show you the isolation levels in dB. Again, read the comments/notes on the second sheet as they'll show you how to read the frequency bands isolation levels according to the formulas.

TL Calculator

This is proven science. You can't deny it. Do the math, build it, and it will work. Don't guess. Don't think "I'll add more or change it later if it doesn't work". You can KNOW that it will work if you DESIGN it correctly. This forum is here to help you design it correctly.

Still trying to debate the thought of adding a split mini for the AC rather than mufflers on my existing HVAC which I had sized for the whole house ( 4.5 ton unit) including coold the garage thats being ocnverted. There's probably enough space in the adjacent hall way to build and to penetrate studio walls with mufflered returns and registers , but the split mini idea is starting to really appeal to me . It would also address a problem we've been having , a two story house with one thermostat , I'm usually freezing year round if my wife has her preferred temperature upstairs .

Good thinking. You ALMOST are on the right track. Mini splits are very common in studio builds. The beautiful thing about them is the fact that you only need around 35% fresh air into your rooms. That means that the duct work to outside is fairly small, and with them, HVAC silencers can be smaller. Where you seem confused is the silencer part. Each room needs FOUR home made, specially designed silencer boxes. They're large. You need to design your rooms to fit these. One for each leaf for supply. And one for each leaf for return. That totals 4 silencers. Mini splits are expensive though. Especially if you have 2 rooms. That means 2 head units. You also have to design it such that the return fresh air is right near the head unit.

The other option will be cheaper, but will eat up more room. That option would be a ducted air handler unit (AHU). Your ducts and silencers would be larger. The ducts would have to be sized to provide at least 6 air changes per hour for each room. You would have to zone the 2 rooms. Then, from that AHU, you'd still need that 35% fresh air piped in from/out to outside. Personally, this is the route I'm going for my 2 basement rooms because I don't want big mini split head units hanging off of my walls and don't want the expense. However, for my drum room, I am planning on using a mini split!

***
The other things you didn't seem to take into consideration were:

-your exterior windows. They will have to replaced with solid laminated glass that match the surface density of your exterior (outer leaf) wall.

- your control room (without building the inner leaf) is only ~14.34 square meters. ITU-R BS.1116-3 states that the minimum size for a listening (control) room is 20 square meters. This doesn't mean it can't happen, but it will never sound amazing and will be very difficult to make sound acceptable. Having said that, you never mentioned what your intended purpose for your studio would be. Self recording for fun? Recording bands with a business license? Your lounge makes me believe it's the latter. If that's the case, I'd recommend you trying to at least meet the listening room size requirements.

- You didn't provide us with ceiling height measurements.

- You live in the space already. If you had read the forum rules, you'd see that we require you to take measurements with a real SPL meter to find out how much isolation your room currently is providing. From there, you (and we) will have a better idea of what would be required to achieve your desired isolation levels.

- Your fridge is in a door way. How are you supposed to get gear into your tracking room?

- What is "duct build in"?

- What is your budget?

I'd personally investigate knocking down the partition wall and make a room big enough to meet the listening room minimum size and at the same time have as big of tracking room as possible. I'd ditch the lounge entirely.

Please fill out the rest of your info, read the forum for a few days and I look forward to your reply. We are here to make you re-think your plans and hopefully in the end come up with amazing ideas/plans so that you have an awesome recording space in the end.

Greg

Hi there. Adding to what Greg said:

Firstly, as Greg pointed out, STC is no use at all for measuring isolation of a studio. Here's why:

STC is no use at all for telling you how well your studio will be isolated. STC was never meant to measure such things. Here's an excerpt from the actual ASTM test procedure (E413) that explains the use of STC.

“These single-number ratings correlate in a general way with subjective impressions of sound transmission for speech, radio, television and similar sources of noise in offices and buildings. This classification method is not appropriate for sound sources with spectra significantly different from those sources listed above. Such sources include machinery, industrial processes, bowling alleys, power transformers, musical instruments, many music systems and transportation noises such as motor vehicles, aircraft and trains. For these sources, accurate assessment of sound transmission requires a detailed analysis in frequency bands.”

It's a common misconception that you can use STC ratings to decide if a particular wall, window, door, or building material will be of any use in a studio. As you can see above, in the statement from the people who designed the STC rating system and the method for calculating it, STC is simply not applicable.

Here's how it works:

To determine the STC rating for a wall, door, window, or whatever, you start by measuring the actual transmission loss at 16 specific frequencies between 125 Hz and 4kHz. You do not measure anything above or below that range, and you do not measure anything in between those 16 points. Just those 16, and nothing else. Then you plot those 16 points on a graph, and do some fudging and nudging with the numbers and the curve, until it fits in below one of the standard STC curves. Then you read off the number of that specific curve, and that number is your STC rating. That's it. There is no relationship to real-world decibels: it is just the index number of the reference curve that is closest to your curve. To clarify: the STC number is NOT how much isolation you will get: it is just the number that somebody once assigned to a curve on a graph. So for the STC-70 curve, they could have called it "STC-GGFQRT" or "STC-Delta-RED" or anything else, and it would tell you just as much about isolation as "STC-70" does: ie, nothing. It's a REFERENCE number, not an actual isolation number.

When you measure the isolation of a studio wall, you want to be sure that it is isolating ALL frequencies, across the entire spectrum from 20 Hz up to 20,000 Hz, not just 16 specific points that somebody chose 50 years ago, because he thought they were a good representation of human speech. STC does not take into account the bottom two and a half octaves of the musical spectrum (nothing below 125Hz), nor does it take into account the top two and a quarter octaves (nothing above 4k). Of the ten octaves that our hearing range covers, STC ignores five of them (or nearly five). So STC tells you nothing useful about how well a wall, door or window will work in a studio. The ONLY way to determine that, is by look at the Transmission Loss curve for it, or by estimating with a sound level meter set to "C" weighting (or even "Z"), and slow response, then measuring the levels on each side. That will give you a true indication of the number of decibels that the wall/door/window is blocking, across the full audible range.

Consider this: It is quite possible to have a door rated at STC-30 that does not provide even 20 decibels of actual isolation, and I can build you a wall rated at STC-20 that provides much better than 30 dB of isolation. There simply is no relationship between STC rating and the ability of a barrier to stop full-spectrum sound, such as music. STC was never designed for that, and cannot be used for that.

Then there's the issue of installation. You can buy a door that really does provide 40 dB of isolation, but unless you install it correctly, it will not provide that level! If you install it in a wall that provides only 20 dB, then the total isolation of that "wall+door" combination is 20 dB: isolation is only as good as the worst part. Even if you put a door rated at 90 dB in that wall, it would STILL only give you 20 dB. The total is only as good as the weakest part of the system.

So forget STC as a useful indicator, and just use the actual TL graphs to judge if a wall, door, window, floor, roof, or whatever will meet your needs.

---

So, assuming you meant "70 dB of isolation", and not "STC-70", that leads to the next question: Why do you think you need 70 dB of isolation? How did you determine that?

As Greg mentioned, getting 70 dB of isolation is a tall order: That's about the physical limit that can be achieved in a home studio build, and requires a very large investment, as well as very careful design, very careful planning, and very careful construction. Slight mistakes in construction can cost you large reductions in isolation. Most home studio builders aim for 40 to 50 dB of isolation, and perhaps 60 dB if they have a really good budget and spend a lot of time on the planning. 70 for a home studio is a very unusual thing. That's approaching the flanking limit for a good concrete slab-on-grade foundation and floor. It is possible to get GREATER than 70, yes, but then you need more advanced techniques (such as floating the entire room on tuned isolation springs) and very high mass materials (and very deep pockets!). That's out of range for most home studio builders, and even for most professional studios.

so I can play with out disturbing my family , and keep noise out of the recordings. even record drums in ISO2

Fair enough. Those are good goals. But have you checked that achieving "STC-70" will meet those goals, and do you have the budget to attain that?

With the space I have , using double wall construction this is a floor plan I think that might work for me , trading some space for hopefully a couple of rooms that will have and STC of 70+

"Thinking" and "hoping" ar not good ways of designing a studio! Rather, you should plan the studio to actually achieve what you "hope" it will achieve, by doing the math and the design. Yes, for high isolation you absolutely will need proper "double wall construction", but that's only the most basic start. Each entire room will need "double-wall", on all sides, INCLUDING the ceiling. A room is not four walls: a room is six sides, which includes four walls and the ceiling and the floor. In your case, the floor is a given, but that still leaves you with the other five: four walls and the ceiling. Each room must be built as a single independent unit that consists of exactly that: four walls and a ceiling, where the ceiling rests on the walls, and none of that touches any part of the existing building.

Looking at clips and channel on the ceiling

That's not going to give you enough isolation to meet your needs. Even though clips are resilient, and do increase isolation, they still provide a partial path for sound and vibration to travel between the sheathing and the framing. Technically, the resilience of the rubber in the clips is in PARALLEL with the resilience of the air, so the rubber dominates and places a limit on how much isolation you can get. It won't be any where near what you need. Clips can get you an additional 15 dB or so beyond what you would have got without them, and for most situations that means a maximum of about 45 dB, or MAYBE approaching 50 dB if you had a really good situation to start with. Far short of what you need. Your only option for high isolation is to have your rooms full isolated. No mechanical connections at all, not even resilient ones.

also adding some mass ( 2*5/8 with GG and rock wool) to the floor above between the joist and using screws to tighten up the hardwood and sub floor layers,

As Greg pointed out, that's not the correct way to do it, because it forces the drywall and subfloor above to act as one single unit, without allowing each part to also act separately, thus reducing your isolation. This is the same as gluing sheets of drywall together: a big mistake. Instead, you should be placing your strips of drywall up against the sub-floor above, holding it in place with cleats nailed sideways into the joists, and sealing around the edges with caulk. Use GG if you want to, and if you have the budget to do that: it does help. But do NOT nail or screw the drywall directly into the subfloor above.

Also, before you do any of that, you need to hire a structural engineer to examine your floor and give you the OK to do that: he can tell you how much extra mass you can safely add to that floor. Do NOT ever add mass to any structural part of your building without first checking with a structural engineer!!! Very important. If you overload your floor and it collapses, your home-owner's insurance policy will NOT cover that, and you will be personally liable for all damages as well as medical expenses of anyone injured in the collapse. You will also be criminally liable for those injuries, or for death if anyone dies.

will add some MLV

There are no magical materials that you can use to cast a spell on your studio and make it isolate better! Yes, MLV is good stuff, and yes it does have uses in studios. But it is just mass, and it s very EXPENSIVE mass. Sound waves can't read, so they are not impressed by the price tag on your mass. They won't stop any better because the price tag said "US$ 50 per kilogram" rather than "US$ 20 per kilogram". All they care about is the total number of kilograms, not how much each one cost. So go with the least expensive mass that will do the job. For most cases, and in most places around the world, that is plain old drywall. It has decently high density at reasonably low cost per kilogram. Other useful materials are OSB and MDF, and perhaps plywood, to a certain extent. Concrete and brick are also good possibilities.

padded engineered flooring at some future point on the floor above .

I guess you mean laminate flooring? That's fine.

Double wall construction with 2x 5/8 on the interior walls with GG

The concept is correct, but I doubt you'll get STC-70, and certainly not 70 dB of isolation, with such low mass.

sound batting ( safe n sound rock wool )

Why did you choose that? What are the coefficients of absorption or the gas flow resistivity for the specific brand and product that you chose? Does that provide the correct acoustic damping on the MSM resonance that will occur inside the wall cavity? How thick will that insulation be? What is the total depth of the wall cavity, and what percentage of the cavity will be filled with insulation? You need high isolation, so all of the above factors are critical, and must be determined carefully, not by guessing.

1 layer of 5/8 on the exterior wall.

I must be misunderstanding something here: I thought those walls already exist, and are unfinished stud-framed walls with sheathing on the outside and nothing else? If that's the case, then why do you want to create a three-leaf system by putting drywall on those unfinished studs? And if my assumption is wrong, and those are already finished walls, that already have drywall on the studs, then you should be taking that existing drywall OFF, not PUTTING MORE on!

You need to clarify what you have there currently. How are those existing walls built? Post some photos.

Still trying to debate the thought of adding a split mini for the AC rather than mufflers on my existing HVAC which I had sized for the whole house

You could go either way, and in BOTH cases you will still need to install ducts ans silencer boxes. If you install a mini-split, you will need ducts and silencers to supply fresh air, remove stale air, and circulate the conditioned air between the rooms. And if you go with the existing HVAC system, you will need ducts to connect your rooms to that system, for both supply and return. In both cases you will need silencer boxes, and they will need to be very large, because you need very high isolation. Personally, if that were my studio, I would probably go with an independent ducted mini-split system dedicated only to the studio, for greater separation and isolation from the rest of the house.

the garage thats being ocnverted.

So this is a garage conversion? It would have been better to clarify that right right from the start. Garage conversions involve factors that basement conversions and house conversions do not.

There's probably enough space in the adjacent hall way to build and to penetrate studio walls with mufflered returns and registers

I VERY MUCH doubt that! I don't think you realize just how big these silencers will need to be! Because you need very high isolation, you will require one silencer on EACH penetration of EACH leaf for EACH duct. You need a supply duct and a return duct for each room. You have two rooms. Each room has two leaves. Do the math: you need eight silencer boxes. They are BIG. If you design the HVAC carefully and split the the flow between the rooms, then combine it again afterwards, you could do it with just six silencers, but they still need to be big. HVAC design for studios is a big deal: When I design a studio for a customer, I often spend as much time designing the HVAC system as I do designing the entire rest of the studio, in all aspects! It's a slow process, there's lots of math involved, and you can't afford to make any mistakes, especially when you need high isolation. Think of it this way: in order to get high isolation, you need two massively dense leaves around each room, each of which is carefully sealed fully airtight, totally hermetic. But for HVAC; you need to chop huge gaping holes in those walls to put the ducts through!!! That totally trashes your isolation, down to nothing. The purpose of the silencer box is to replace the missing isolation: the silencer is carefully designed to stop the sound from getting through, while allowing the air to get through. It's not easy to do that. The silencer is a tuned system, that uses several different characteristics and acoustic effects to stop the sound getting through, including mass, MSM, impedance mismatch, flow velocity changes, insulation, and multiple 90° bends. It's not simple. We are not talking about the typical flimsy metal cylindrical silencers that are commonly used in commercial HVAC ducting. Studio silencers are very different, they are BIG, and you don't seem to be allowing any space for them.

There's a lot more that you'll need to take into account here, and Greg already covered many of those so I won't repeat that.

In summary, you have the right basic concept here, but the details are going to need a lot of attention.


- Stuart -

My name is Blake Braught and I'm a singer song writer and I think I love recording and mixing as much as playing good music , so the idea of the studio is for friends and church members , song writers etc to have a place to record .

I already have a music room with just sound batting in the walls, and 1/2 drywall with very connected framing . thats the 10x16 room in the diagram . We just replaced our garage doors with french doors and that is an ingress egress ingress point into the house , so I can't have all the space , and we BBQ out there and the kitchenette would be for my wife and friends kids etc. and band mates and collaborators when we have them over.

So it's not a business but I would like to be able to make great recordings, and the control room will be where I spend most of my time , writing and singing , which wakes up my daughter above me, so I need to fix that. I like to write when the mood takes me and that might be at 3 am .

The ceiling height is 97.5 inches concrete to the bottom of the floor joist.

Oh that's a pocket door by the fridge , the door slides open and closed. The hallway is strait .

The outer wall is cinder block at it's base sub ground , and double walled on top it with a really deep wall under the cantilevered rooms above it's 8" thick with black board and brick on the above ground portion. The rest of the walls are 2x4 with 1/2 inch drywall. on the interior walls , the long garage wall is 2x4 with black board and brick exterior.


There is no ISO 1 yet , thought about carving a corner out somewhere for a vocal booth int the control room.

Also this will be multi purpose ISO 2 and the lounge area will house a young lady and her children for a season , I want to build it so that it works for both purposes . I can play music at night , and our guests have a separate kitchen , which will no doubt be used by my wife and I an guest when they are gone.

I will no doubt but some xlr receptacles and some head phone jack there too who knows right? .

I actually do need this forum , but the family in question is sleeping in my living room so , under a bit of time pressure.

From your post ... I've gathered .

I will not use clips and channel on the cieling , and I really need to learn more about the venting , and or muffer-ing.

I did figure what ever I do with the ceiling with be under the 97.5 inches of the existing joist , there is too much blocking to interleave decoupled joist , if I can manage to span 9 feet with 2x4s under ceiling height will be 7.64 feet or so with two layers of 5/8 inch drywall. If it will allow me to play guitar and sing at 3 am I will do that .

And really that is this test , can I belt out some tunes , record harmonies and play and acoustic guitar , mix some tracks ( on 5) and not disturb anyone in the house , because that is all the isolation I need.


Oh I don't have a huge budget .. will finance part of it materials you can get at home depot. have a lot of cheap labor ( me and kids) and some moderate framing skills. Perhaps there is a consultation opportunity here , but I need to move quickly so if your are interested .. message me for my number and email.

Thanks,


Blake

Hi Blake,

You've ignored my 2 requests to read the forum rules (which require you to fill out your profile information in more detail), so please out of respect for the forum, do that right now before you even read the rest of my reply. Thank you.

I'm a singer song writer and I think I love recording and mixing as much as playing good music , so the idea of the studio is for friends and church members , song writers etc to have a place to record .

Excellent.

So it's not a business but I would like to be able to make great recordings, and the control room will be where I spend most of my time , writing and singing , which wakes up my daughter above me, so I need to fix that. I like to write when the mood takes me and that might be at 3 am .

So are you not going to record drums or anything loud like that? Just acoustic guitar and vocals? This is VERY important to know. Acoustic guitar and vocals require MUCH less isolation than drums.

The ceiling height is 97.5 inches concrete to the bottom of the floor joist.

The solution for your inner leaf ceiling is an inside out design which was invented by John Sayers, the master of studio design.

You don't have any room to play with height-wise so your ventilation (which you CANNOT ignore) silencer boxes must live either both inside and outside of your walls, or else (depending on whether you need that extra isolation for loud things like drums) they can live on one or the other. Since your control room is already tiny, you will probably want it outside of your room. I'm hoping you say you will only ever record acoustic guitar and voice for this reason.

There is no ISO 1 yet , thought about carving a corner out somewhere for a vocal booth int the control room.

This isn't going to happen. Vocal "booths" are usually imagined as tiny little rooms where a singer just barely fits with a microphone. This is the worst idea ever. The only time a small booth like that should exist is if you're cutting guide tracks with a live band and you need some separation. The vocals would then be over dubbed in a bigger good sounding room. Small rooms sound horrible. My personal vocal booth is probably bigger than your control room, and I wish my vocal booth was bigger for better acoustics. Also, your control room, as Stuart and I both told you before, is already too small to ever be an acceptable sounding control room, so the idea of eating up more space in it for a vocal booth is absurd.

Also this will be multi purpose ISO 2 and the lounge area will house a young lady and her children for a season , I want to build it so that it works for both purposes . I can play music at night , and our guests have a separate kitchen , which will no doubt be used by my wife and I an guest when they are gone.

I understand now that the recording space is taking a back seat to more important things. That's totally understandable, but you have to realize that your rooms won't ever sound great if you're unable to find more space. But, for safety reasons you need to make sure you have proper ventilation in the recording rooms and that will eat into more of your space and budget.

I will no doubt but some xlr receptacles and some head phone jack there too who knows right? .

There's always going to be something you wish you had at some point!

I will not use clips and channel on the cieling , and I really need to learn more about the venting , and or muffer-ing.

Awesome. After you fill out your profile, feel free to ask us some questions about the HVAC. I too am studying it as like all studio design aspects, you search for the answer for one question and by the time you've found the answer, you have 5 more related questions.

My name is Blake Braught and I'm a singer song writer and I think I love recording and mixing as much as playing good music , so the idea of the studio is for friends and church members , song writers etc to have a place to record .

I already have a music room with just sound batting in the walls, and 1/2 drywall with very connected framing . thats the 10x16 room in the diagram . We just replaced our garage doors with french doors and that is an ingress egress ingress point into the house , so I can't have all the space , and we BBQ out there and the kitchenette would be for my wife and friends kids etc. and band mates and collaborators when we have them over.

So it's not a business but I would like to be able to make great recordings, and the control room will be where I spend most of my time , writing and singing , which wakes up my daughter above me, so I need to fix that. I like to write when the mood takes me and that might be at 3 am .

The ceiling height is 97.5 inches concrete to the bottom of the floor joist.

Oh that's a pocket door by the fridge , the door slides open and closed. The hallway is strait .

The outer wall is cinder block at it's base sub ground , and double walled on top it with a really deep wall under the cantilevered rooms above it's 8" thick with black board and brick on the above ground portion. The rest of the walls are 2x4 with 1/2 inch drywall. on the interior walls , the long garage wall is 2x4 with black board and brick exterior.


There is no ISO 1 yet , thought about carving a corner out somewhere for a vocal booth int the control room.

Also this will be multi purpose ISO 2 and the lounge area will house a young lady and her children for a season , I want to build it so that it works for both purposes . I can play music at night , and our guests have a separate kitchen , which will no doubt be used by my wife and I an guest when they are gone.

I will no doubt but some xlr receptacles and some head phone jack there too who knows right? .

I actually do need this forum , but the family in question is sleeping in my living room so , under a bit of time pressure.

From your post ... I've gathered .

I will not use clips and channel on the cieling , and I really need to learn more about the venting , and or muffer-ing.

I did figure what ever I do with the ceiling with be under the 97.5 inches of the existing joist , there is too much blocking to interleave decoupled joist , if I can manage to span 9 feet with 2x4s under ceiling height will be 7.64 feet or so with two layers of 5/8 inch drywall. If it will allow me to play guitar and sing at 3 am I will do that .

Interleaved is not the answer. Inside out ceiling is. Sorry to be a broken record on this answer, but again, are you ONLY ever going to be recording acoustic guitar and vocals?

And really that is this test , can I belt out some tunes , record harmonies and play and acoustic guitar , mix some tracks ( on 5) and not disturb anyone in the house , because that is all the isolation I need.

I'm starting to believe that you are never going to record guitar amps or drums, ever.

Oh I don't have a huge budget .. will finance part of it materials you can get at home depot. have a lot of cheap labor ( me and kids) and some moderate framing skills.

Throw a number at us? $500, $5000, $15,000, $50,000? Doing it yourself and not spending money on a contractor will save you heaps of money. But saving money often means losing time. I have a feeling you're either going to give up on this idea because you'll realize it will either cost too much or take too long. If you pull through and build the space, you're going to have to face the fact that it will either cost you more than you expected, or you're going to have to build it yourself which will take you 10 times longer than you thought it would. I sure hope it works out great for you in the end.

Perhaps there is a consultation opportunity here , but I need to move quickly so if your are interested .. message me for my number and email.

Consultation on here is free. For an actual design, that will cost you a lot of money if you want it to actually work (AKA have a design made by someone who ACTUALLY knows what they're doing). If someone contacts you and it's affordable, chances are it's a scammer or someone who doesn't know what they're doing. My advice is to get the free consulting here and invest some time into learning how to build it correctly and save money of which you can spend buying proper materials.

Greg

Gregwor wrote:Welcome clearvoice (whatever your real name is)!

Please read the Forum Rules as you are missing some required information in your profile! The forum is very strict about these rules.

I'm wanting and STC greater than 70 in my control room and the Is0 2 room . so I can play with out disturbing my family , and keep noise out of the recordings. even record drums in ISO2 .

I'll start by suggesting that you spend a few solid days, or weeks reading some threads on the forum and you'll see that the answers you seek, plus a TON more information, is all here. The forum is a great source for people like you and I that are trying to design and build our dream studies in our homes and even commercial locations.

Having said that, it is said again and again on the forum that STC is not the proper measurement for full range instruments. You'll also see on the forum that achieving 70dB of isolation is VERY hard to do without going to extremes and spending hundreds of thousands of dollars. Upwards of 60 is achievable with careful planning and very careful building. If you use the search feature on the forum, type in STC and I'm confident that one of the first results will show a big rant done by Stuart (Soundman2020) explaining in detail why STC is not valid in recording studio design.

the Is0 2 room

Where is ISO room #1?

With the space I have , using double wall construction this is a floor plan I think that might work for me , trading some space for hopefully a couple of rooms that will have and STC of 70+

You're obviously wanting to contain the energy of a drum kit from the rest of the house. That means you NEED to use MSM construction. So yes, "double wall construction". The floor plan looks almost decent considering what you have to work with. However, do you NEED a lounge? Are you going to have lots of people over during recording sessions that you need to occupy and keep out of the control room during tracking sessions? If not, I'd highly recommend using that space for your tracking room. Bigger always = better in recording spaces. Again, I will say that STC means nothing here. And basically, you should shoot for as much isolation as you can afford both space wise and financially if you want to record drums without disturbing neighbours or your family/room mates.

Looking at clips and channel on the ceiling

Nope. Clips and channel on the ceiling will not provide enough isolation in the problematic low frequencies for the level of isolation you've described. You'll need to build a full MSM system. That means resting LVL studs across your inner leaf walls. This will allow your ceiling to not touch the rest of the house (the outer leaf) at all except via the walls to the concrete slab on which they rest. Earth is a good enough damper to provide great isolation.

also adding some mass ( 2*5/8 with GG and rock wool) to the floor above between the joist and using screws to tighten up the hardwood and sub floor layers, will add some MLV and padded engineered flooring at some future point on the floor above .

Yes. You WILL have to add that mass to the floor above, from below using cleats to hold the 5/8" + Green Glue against the existing sub floor above. NOT screws. You can do the math to figure out if you need the extra mass above. But remember, MLV is VERY expensive and you would have to get an engineers stamp to add that kind of mass to the floor. Already, adding two layers of 5/8" drywall to the underside of that floor might be maxing the floors load limit.

Double wall construction with 2x 5/8 on the interior walls with GG, sound batting ( safe n sound rock wool ) and 1 layer of 5/8 on the exterior wall.

You didn't tell us what the exterior wall is made of. Most homes where I live are sheathed with 3/8" OSB. So, adding only 1 layer of 5/8" drywall to it might not be enough. Again, you're going to have to do the math to figure out how much mass (and gap) you need to achieve your required transmission loss levels. Here is a transmission loss excel spreadsheet I threw together. Read the comments/notes on the right of sheet 1. You can change values to match your construction and then the second sheet will show you the isolation levels in dB. Again, read the comments/notes on the second sheet as they'll show you how to read the frequency bands isolation levels according to the formulas.

TL Calculator

This is proven science. You can't deny it. Do the math, build it, and it will work. Don't guess. Don't think "I'll add more or change it later if it doesn't work". You can KNOW that it will work if you DESIGN it correctly. This forum is here to help you design it correctly.

Still trying to debate the thought of adding a split mini for the AC rather than mufflers on my existing HVAC which I had sized for the whole house ( 4.5 ton unit) including coold the garage thats being ocnverted. There's probably enough space in the adjacent hall way to build and to penetrate studio walls with mufflered returns and registers , but the split mini idea is starting to really appeal to me . It would also address a problem we've been having , a two story house with one thermostat , I'm usually freezing year round if my wife has her preferred temperature upstairs .

Good thinking. You ALMOST are on the right track. Mini splits are very common in studio builds. The beautiful thing about them is the fact that you only need around 35% fresh air into your rooms. That means that the duct work to outside is fairly small, and with them, HVAC silencers can be smaller. Where you seem confused is the silencer part. Each room needs FOUR home made, specially designed silencer boxes. They're large. You need to design your rooms to fit these. One for each leaf for supply. And one for each leaf for return. That totals 4 silencers. Mini splits are expensive though. Especially if you have 2 rooms. That means 2 head units. You also have to design it such that the return fresh air is right near the head unit.

The other option will be cheaper, but will eat up more room. That option would be a ducted air handler unit (AHU). Your ducts and silencers would be larger. The ducts would have to be sized to provide at least 6 air changes per hour for each room. You would have to zone the 2 rooms. Then, from that AHU, you'd still need that 35% fresh air piped in from/out to outside. Personally, this is the route I'm going for my 2 basement rooms because I don't want big mini split head units hanging off of my walls and don't want the expense. However, for my drum room, I am planning on using a mini split!

***
The other things you didn't seem to take into consideration were:

-your exterior windows. They will have to replaced with solid laminated glass that match the surface density of your exterior (outer leaf) wall.

- your control room (without building the inner leaf) is only ~14.34 square meters. ITU-R BS.1116-3 states that the minimum size for a listening (control) room is 20 square meters. This doesn't mean it can't happen, but it will never sound amazing and will be very difficult to make sound acceptable. Having said that, you never mentioned what your intended purpose for your studio would be. Self recording for fun? Recording bands with a business license? Your lounge makes me believe it's the latter. If that's the case, I'd recommend you trying to at least meet the listening room size requirements.

- You didn't provide us with ceiling height measurements.

- You live in the space already. If you had read the forum rules, you'd see that we require you to take measurements with a real SPL meter to find out how much isolation your room currently is providing. From there, you (and we) will have a better idea of what would be required to achieve your desired isolation levels.

- Your fridge is in a door way. How are you supposed to get gear into your tracking room?

- What is "duct build in"?

- What is your budget?

I'd personally investigate knocking down the partition wall and make a room big enough to meet the listening room minimum size and at the same time have as big of tracking room as possible. I'd ditch the lounge entirely.

Please fill out the rest of your info, read the forum for a few days and I look forward to your reply. We are here to make you re-think your plans and hopefully in the end come up with amazing ideas/plans so that you have an awesome recording space in the end.

Greg

Welcome clearvoice (whatever your real name is)!
My name is Blake Braught I live in Memphis , Tennessee USA

Where is ISO room #1?
There is no ISO #1 , I deleted it and didn’t change the name on the plan , it was going to be a vocal booth for isolation inside the control room , but I decided to fix the entire room.
I think if life and time allows the living room will be my listening room /theater mix room and the control room will become ISO 1 , I will have the lower level for recording.


you NEED to use MSM construction
I don’t know what MSM means , could you explain?
LVL studs?
Not sure what LVL is but I understand your point, and from your comment I will build 2x4 joist on the inner room frame to hang two layers of 5/8 drywall ( if it will support it on 9 foot span 16OC)

However, do you NEED a lounge?
The area is not exclusively mine, and the area is an ingress/egress for the house, and for guest.
The other thought is the lounge is a third room for isolation from the other two, and a fourth will be my living room , so I will strategically have some xlr and headphone stations for that purpose.

record drums without disturbing neighbours or your family/room mates.
Any drum recording would be daytime hours, but I would like enough isolation if we did record drums , honestly there are other project studios I farm the drums out to , my work is usually vocals , acoustic guitars , miked amps or direct instruments . I will probably get a baby grand or a nice upright at some point , the upright would likely go in ISO2 the baby grand would go in my living room.

You WILL have to add that mass to the floor above, from below using cleats to hold the 5/8" + Green Glue against the existing sub floor above.

This house is really old construction, 2x 8 joist on the ceiling above , 1 x 8 inch sub floor slats at a 45 degree and ¾ inch oak hardwood on it. Do I try to fasten both layers of drywall at the same time ? or use two different size cleat nails ? And curious to what problems screws would create ? Should I hang the other drywall in the same manner or was this specifically for the mass being added underneath the floor ?

You didn't tell us what the exterior wall is made of

In the diagram North is down …
The south wall ( on the top of the diagram)
Bottom 3 feet layer ( 5/8 , 5/8 2x4 with sound bat 1 inch gap 8 inch cinderblock wall , dirt)
Top 5 feet ( 5/8, 5/8 2x4 with sound bat ( safe and sound rock wool ) 1 in gap 8 inch 2x8 r19 blackboard 1 in gap masonry wall)

All other exterior wall are 2x4 with blackboard and brick exterior.

Interior walls are ½ inch drywall with 2x4 construction


-your exterior windows. They will have to replaced with solid laminated glass that match the surface density of your exterior (outer leaf) wall.

They are currently double paned , really good windows , most likely will build some kind of plug for them on the interior leaf , or what ever is needed not a high priority for the moment.

- your control room (without building the inner leaf) is only ~14.34 square meters.
It’s all the space I have for now, this plan is a compromise for other uses, will treat it as best I can for a decent sound, will probably use my living room space for listening and mixing in the future.

what your intended purpose for your studio

Recording an EP with my own and collaborates songs for publishing , and just need a space that provides enough isolation for guitars , miked amps , direct instruments , singing .. to make clean recordings . I may try to mike a drum kit in the future but , will probably in all honesty will farm that out , or track at another studio or the church down the road in a 40x75 sanctuary with a 30 foot arched wood ceiling .

I do have a Marshall 4x12 cabinet and that would certainly be miked in another room , just so I can crank it to it’s sweet spot. I will probably get and upright and put it in ISO 2 and be able to play it at night as well if possible.

But seriously I work on vocals a lot more than anything else and that is what I need to contain for night time use , that and live play in the room , with a couple of KRK rockit 8s reference monitors , and mixing in this tiny room for now.

- You didn't provide us with ceiling height measurements.

97.5 inches from concrete to the bottom of the bare joist. I know that because the drywall is already off.

- Your fridge is in a door way. How are you supposed to get gear into your tracking room?
That is a pocket door in the closed position, the white space next to the fridge is not a door threshold it is the hollow portion of the wall where the pocket door will retract , the path into the house is relatively strait.

- What is "duct build in"?

This was built into my current music space , a 16” x 16” x 10’ foot box on the ceiling and down one side of the wall, that houses the air duct, this house is old and ducting on the lower level uses these. I was going to using the same concept for the mufflers in the hall way north of ISO 2 and the control room , and remove the ones currently in the control room , so the penetration in to the room is away from the HVAC and away from the east wall which is load bearing and seriously connected to the room above the living room outside by the stairwell .

- What is your budget?

Initially 10K over six months , 10K more over a year .

I may get some help framing , but most of this we will do , and it doesn’t have to be all completed immediately but I want a plan that will meet my future goals of doing serious recording and song writing , we would like to have the control and ISO rooms done in 4 weeks, once I make these final decisions we are going to start framing , I’d hoped to start tomorrow , but I though I’d run the plan by you guys first , glad I did , I’m going to frame room in room ( no clips or channel), and I’ll try to detail the plan for ISO and control room . The biggest thing will be the mufflering plan for the returns and registers , I may just hang one door ( outer lead door) on ISO two until my guest are gone but I want to build it to spec.

The other aspect is the lounge is underneath my bed room , so that is going to have to be quiet , but not crazy isolated , something you would expect in a good apartment complex. Think , 2 layers of 5/8 drywall with GG , safe and sound between the joist , and just 5/8 on the ceiling should be sufficient isolation for speech and noises that are generated from each location such as TV s or other human interactions.

I'd personally investigate knocking down the partition wall and make a room big enough to meet the listening room minimum size and at the same time have as big of tracking room as possible. I'd ditch the lounge entirely.

I think with the shared use this is the best I’m going to get , as we become empty nesters in the next couple of years , I will likely get the living room for the purpose of mixing , and open up the floor plan upstairs for my wife’s living room and hobbies room etc. I think the lounge will have a nice use too for the socials aspect of music , as there will be a nice adjoining patio with a grill and such and a table outside for people on nice days and evenings . Good for hosting house concerts , song writer workshops , family or church events etc.
Also I may be having some kids record vocals and their parents sitting in the lounge will be family friendly, maybe has a cameras and an HDMI feed to the monitor in the lounge. Which is another point , no windows , will use monitors and cameras for interactions between rooms if needed.

So about those muffler plans … I’ll try to draw what I am thinking , and maybe you kind folks can help me flesh out the hvac solution , building mufflers with out the split min may be the higher difficulty lower cost option I go with since I already shelled out 4500 for the new HVAC , lets try that and see how far I can get.

I don’t know what MSM means , could you explain?

It stands for Mass, Spring, Mass. It's the most effective and affordable way to build a room and achieve great transmission loss. The two components of mass are fully decoupled from one another and the spring component is actually insulation. So, basically, a room in a room where the only place the rooms touch one another is on the concrete slab. For rooms on second floors, everything gets more complicated because the floor joists do not act like the amazing damper Earth does on a ground level build.

Not sure what LVL is but I understand your point, and from your comment I will build 2x4 joist on the inner room frame to hang two layers of 5/8 drywall ( if it will support it on 9 foot span 16OC)

Google LVL stud. It's an engineered stud. You're able to hold more weight over larger spans using smaller dimension lumber.
Regarding your 2x4 ceiling joist idea, google it and there are a handful of online calculators and charts showing how far you can use dimensional lumber to span ceilings holding x amount of weight. No matter what, this is something you cannot avoid checking. Ideally you will want to get an engineers stamp to cover your ass and pass building inspection. I recommend LVL stud because maybe you can get by using small lumber for that span vs larger dimensional lumber. Tip: sistering joists allows you to carry more load. It's not nearly as efficient as having a stud with more depth, but it helps. Also, building your inner leaf ceiling inside out will allow you to save a lot of ceiling height in the end.

my work is usually vocals , acoustic guitars , miked amps or direct instruments

Amps = loud. You will need adequate isolation.

Do I try to fasten both layers of drywall at the same time ? or use two different size cleat nails ? And curious to what problems screws would create ? Should I hang the other drywall in the same manner or was this specifically for the mass being added underneath the floor ?

There's no real easy way to do it. Luckily you will have help (an extra set of hands to hold stuff). The cleats will actually be fastened to the joists and not through the drywall. The cleats are there to hold the drywall up against the bottom of the sub floor with GG between them. You will want to seal the sub floor joints before installing the drywall and you'll want to seal the drywall joints after installing them. Screwing the drywall to subfloor will lessen the effect of the GG and instead of having the layers work their magic independently AND as a whole, it will only work as a whole. Basically, it won't work as good, so it's not worth it if you can avoid it. This method using cleats is only for adding mass to existing ceiling or walls where you're beefing up the mass between studs or joists.

They are currently double paned , really good windows , most likely will build some kind of plug for them on the interior leaf , or what ever is needed not a high priority for the moment.

If you're going to plug them, cool.

It’s all the space I have for now, this plan is a compromise for other uses, will treat it as best I can for a decent sound, will probably use my living room space for listening and mixing in the future.

This isn't the right vision to have. If you're devoting money and time to your spaces, decide what each room will be used for and purpose build them to perform well as such. You can't just easily make a control room into a live room or vice versa.

97.5 inches from concrete to the bottom of the bare joist. I know that because the drywall is already off.

That's short, so an inside out ceiling is your only real option here.

- What is "duct build in"?

This was built into my current music space , a 16” x 16” x 10’ foot box on the ceiling and down one side of the wall, that houses the air duct, this house is old and ducting on the lower level uses these. I was going to using the same concept for the mufflers in the hall way north of ISO 2 and the control room , and remove the ones currently in the control room , so the penetration in to the room is away from the HVAC and away from the east wall which is load bearing and seriously connected to the room above the living room outside by the stairwell .

You will need areas like this devoted to your duct work and silencer boxes. And they'll be large just like this (but probably bigger).

Initially 10K over six months , 10K more over a year .

Awesome. That should get you going!

I may get some help framing , but most of this we will do , and it doesn’t have to be all completed immediately but I want a plan that will meet my future goals of doing serious recording and song writing , we would like to have the control and ISO rooms done in 4 weeks, once I make these final decisions we are going to start framing , I’d hoped to start tomorrow , but I though I’d run the plan by you guys first , glad I did , I’m going to frame room in room ( no clips or channel), and I’ll try to detail the plan for ISO and control room . The biggest thing will be the mufflering plan for the returns and registers , I may just hang one door ( outer lead door) on ISO two until my guest are gone but I want to build it to spec.

I know you don't want to read this but I promise if you don't listen, you'll waste time and money and your plan will NOT work.

You NEED to download SketchUp Make:
https://help.sketchup.com/en/downloading-older-versions

Spend some time getting familiar with this. Watch some YouTube tutorials in 1.5 or 2x speed and get the basics such as making components, using inference, using layers.

Draw your space as accurately and with as much detail as possible. Then draw your studio plan in as much detail. Draw every stud as it's going to be built. Figure out exactly where all of your duct work will go, electrical, signal level penetrations, etc. How will you decouple your conduit runs between your room so that they don't flank and trash your isolation? What about avoiding big holes in your walls where your electrical outlets will be? What doors will you use? What door hinges? What seals will you use on your doors? You'll need to take things like the bottom of the door jamb being present unlike a typical home door. How much higher will this set the top of your door rough opening? SketchUp design will tell you! Where will you sit in your mixing room? Where will your speakers go? Where will you frame your control room door rough opening so that it won't screw up acoustic treatment? Where will your silencer boxes go? How big will they be? Where will fresh air come from and how big will that duct work be? What about stale air?

What I'm saying is, imagine you just frame up the rooms and then have no where to put things like HVAC? Tear it down, throw out all of the supplies, waste time, then design it and build it? OR, design it now, then build it once, correctly. This will take a while because you need to learn how to design it. Sadly, you don't have the budget to hire an amateur like myself even let alone a seasoned pro like John to design it for you. All of the answers ARE on this forum, for free. And we are here to answer questions for you, for free. You just need to find the time and put in the time to read, take notes, save pictures, organize topics, then design it. I mean heck, SketchUp will take you a while to get comfortable on even. A realistic time frame is several months worth of learning and designing, then building. It will be 90% design time and 10% build time.

The other aspect is the lounge is underneath my bed room , so that is going to have to be quiet , but not crazy isolated , something you would expect in a good apartment complex. Think , 2 layers of 5/8 drywall with GG , safe and sound between the joist , and just 5/8 on the ceiling should be sufficient isolation for speech and noises that are generated from each location such as TV s or other human interactions.

You could maybe use RSIC clips for this room.

So about those muffler plans … I’ll try to draw what I am thinking , and maybe you kind folks can help me flesh out the hvac solution , building mufflers with out the split min may be the higher difficulty lower cost option I go with since I already shelled out 4500 for the new HVAC , lets try that and see how far I can get.

Call them silencer boxes from now on so that other readers know what you're referring to. The forum rules indicate that SketchUp drawings are the ones that everyone here will understand when looking at them. Please draw them in that program.
Hint: design your CFM so that you have at least 6 air changes per hour in your rooms.

I look forward to your journey here. Just please, take our advice. We only want you to save money and have awesome rooms that are safe and sound decent.

Greg

Ok after much thinking on what your advised, and playing with listening room requirements and golden ratios , This is one possibility that i really like.

One large control Room and one ISO booth...

Plan,
I ditch the lounge and share my upstairs kitchen with the guest, down size my 10x16 room to 10x12 ( future ISO 1) and give that to the guest now, and have the one large listening /control room that is a golden ratio I can also record most of my tracking in .

I can give the 10x12 room ( first priority) with current ventilation , work on the 20 x 12 x 7.5 room as time and money allow .


Problems.



Span , I have to span 12.5 feet lengths underneath the 97.5 inch existing joist

" changing current doors to out-swinging double 30" doors , adding interior double door isolation (solid core..)

Through traffic

The interior double doors will have to be open and allow for through traffic for daytime use, be ascetically pleasing , but closed for superior sound isolation/security at night and while working in the studio.

I 'm not terribly concerned about my neighbor on that side of the house, he is an old hippy and likes his rock an roll , I'm more concerned about flanking noise making it back into the house upstairs ... the doors are definitely going to be a weak point. Can it be solved ? They are currently double paned 30x80 french doors , the framing around the doors is the weak spot , think 1" paneling on the side panel build in construction ( they are pretty) with no insulation. Will have to add as much mass to it as I can fit in there, maybe a little extra gap between walls on that side to accommodate building that up , and sealing air tight.


Trying to balance listening/control with live room functionality '


notes:


Talked to a architect , he doesn't think the 2 X 5/8 drywall between joist would be that significant of a load on the current framing , if that is all the weight we are adding to the floor.


I would really enjoy having that much space and it would lend it self to some video work as well, and putting the 60" between my near fields and sit the sofa in the back and we have a theater

We can still do the patio furniture with the grill and have guest, and a sofa and chairs , just no kitchen ( that's the case now ).

I'm really warming up to this idea.

Ok after much thinking on what your advised, and playing with listening room requirements and golden ratios

There is no such thing as a golden ratio. Basically just make it as big as you can and don't have any of the 3 dimensions the same or within 5% of one another. After that, you should be good to go. This new design you came up with looks WAY better. However, there is an issue with the wall/door layout for your ISO booth. If that's a sound lock there, you only will have one wall in the sound lock for your ISO booth with one door on it. The only issue with having a sound lock there is that you will need all 4 doors on it to be heavy and air tight.

Span , I have to span 12.5 feet lengths underneath the 97.5 inch existing joist

I'd put money on it that a 2x8 LVL stud would do that no problem. Acoustically, your ceiling height will always be the same when you build it inside out. Only the visual height will be less and less with thicker wood. Don't let it bum you out though. It's all about the acoustics, not the visual.

the doors are definitely going to be a weak point. Can it be solved ?

Yes, there are always door solutions. The only issue is $$$$. Nice doors with lots of glass will always cost a fortune. That's why most people build their own solid core doors.

The interior double doors will have to be open and allow for through traffic for daytime use, be ascetically pleasing

Like everything in the construction business, you can only have 2 of these 3 characteristics: beautiful, cheap and functional. You choose.

Talked to a architect , he doesn't think the 2 X 5/8 drywall between joist would be that significant of a load on the current framing , if that is all the weight we are adding to the floor.

That weight would be fine (but it is good to check). The reason I say this is because in newer build, they are designed to have drywall fastened to the bottom of the joists. Not two layers of heavy 5/8", but ultralight 1/2" plus some mechanical.

I would really enjoy having that much space and it would lend it self to some video work as well, and putting the 60" between my near fields and sit the sofa in the back and we have a theater

It makes it an easier sell to the spouse doesn't it?

I'm really warming up to this idea.

I'm glad to hear that we didn't scare you off. Now download SketchUp Make like I said and let's see some drawing progress! At least get your shell drawn up in 3D in that program instead of the one you've been using. Be sure to use layers and include every ceiling joist as you're going to need to know those measurements to try and fit your HVAC.

Greg

Here is my skechup drawing of the HVAC plan.

What should the silencers be constructed out of ?

What should they be lined with ?

Is an 8" feed going to be sufficient for a 21 X 12 room ( well insulated) ?

Will I need fans to boost air flow ?


Thanks .


Blake

What should the silencers be constructed out of ?

Use whatever material you need to get roughly the same surface density as that of the leaf itself. Usually that means a layer or two of MDF, OSB, plywood or something similar.

What should they be lined with ?

a 1" thickness of proper duct liner, designed specifically for the interior of HVAC ducts.

Is an 8" feed going to be sufficient for a 21 X 12 room ( well insulated) ?

You'll have to do the math to figure that. you need a flow velocity no higher than 300 fpm at the registers, and a flow rate that is high enough to give you at least 6 room changes per hour. Based on that, you can determine what size ducts you need.

Will I need fans to boost air flow ?

That depends on which specific model of AHU you choose, and also on the static pressure that your duct/silencer box/register system will impose. If your AHU can handle that static pressure all by itself, then you do not need additional fans. If the AHU can't handle it, then you will need fans, or you will need to re-design the duct system to have lower static pressure.


- Stuart -

Yes. You WILL have to add that mass to the floor above, from below using cleats to hold the 5/8" + Green Glue against the existing sub floor above. NOT screws.

Prepping for the inner leaf...

Getting to the point where I need to add mass to the open floor above before framing the inner leaf, what do you mean by fastening with cleats rather than screws ? A type of nail ? Or some kind of suspension rail ? Can you detail a method for this? Nail through to the sub-floor or try to suspend the drywall inserted between the joist by nailing into the floor joist?

Also the house is old 1965 .. so the floor above is like a piano sound board . The sub-floor is 8x1 slats installed at a 45 with and 1/8 -1/4 in inch gap between slats , you can see the plastic vapor barrier and the hardwood flooring above through the gaps from below, and you can certainly hear through it well. Would it be worth putting a bead of acoustical caulking in those gaps in the sub-floor before adding the two layers of 5/8 drywall and GG ?


Should I add mass to the exterior walls , 2X4 frame , 1/2 " Black Board , 2" gap , and standard brick masonry wall .

Getting to the point where I need to add mass to the open floor above before framing the inner leaf, what do you mean by fastening with cleats rather than screws ? A type of nail ? Or some kind of suspension rail ? Can you detail a method for this? Nail through to the sub-floor or try to suspend the drywall inserted between the joist by nailing into the floor joist?

Would it be worth putting a bead of acoustical caulking in those gaps in the sub-floor before adding the two layers of 5/8 drywall and GG ?

Yes

Should I add mass to the exterior walls , 2X4 frame , 1/2 " Black Board , 2" gap , and standard brick masonry wall .

Use my transmission loss calculator to determine how much mass you need on your walls to maintain your required isolation on your ceiling and walls.

Greg

Gregwor wrote:

Getting to the point where I need to add mass to the open floor above before framing the inner leaf, what do you mean by fastening with cleats rather than screws ? A type of nail ? Or some kind of suspension rail ? Can you detail a method for this? Nail through to the sub-floor or try to suspend the drywall inserted between the joist by nailing into the floor joist?

Darren Subfloor Beef.jpeg

Would it be worth putting a bead of acoustical caulking in those gaps in the sub-floor before adding the two layers of 5/8 drywall and GG ?

Yes

Should I add mass to the exterior walls , 2X4 frame , 1/2 " Black Board , 2" gap , and standard brick masonry wall .

Use my transmission loss calculator to determine how much mass you need on your walls to maintain your required isolation on your ceiling and walls.

Greg

Thanks I found the construction method after doing more research , I'd never heard of that before.. Maybe overkill I just ripped a 2x4 and put up along length of the drywall insert... I guess that's more mass .

AS I'm getting nearer to the inner leaf ... I have one more thought rather than having a 12x21 control room , making it into a smaller control room with two iso rooms , and a wash room that would provide for some miked amps ...
An thoughts on that use of the space

I have one more thought rather than having a 12x21 control room , making it into a smaller control room with two iso rooms , and a wash room that would provide for some miked amps ...

Smaller is worse! Always.

Check the specs for control rooms, such as ITU BS.1116-3 and you'll find that the minimum recommended floor area or a critical listening room is 20 m2, which is about 215 ft. With 12x21 you have 252 ft2. So the MAXIMUM you could spare, is about 40 ft2. If you try to divide that 40ft into three other rooms, each one would be measure about 3' x 4', but you also have to allow for isolation, so the actual interior space of each "room" would be about 2' x 3'.... I've seen larger closets!

OK, so you could go smaller than 215 ft in the control room and still have it decent, but you'd never want to go smaller than maybe 180 ft2. So you could spare 72ft2 in that case. Split int three = 24 ft2 each, so maybe 6' x 4', less isolation walls = maybe 5' x 3' interior space... What can you do in a room that measures 5' x 3'? That's barely big enough to stand up in and stretch out your arms... and the acoustics would be terrible.

You could MAYBE split that space into a 190ft2 control room and a +/- 45 ft2 vocal booth. That's about as small as you'd want to go for a vocal booth, and for a control room. That would be a reasonable compromise. Any smaller, and you'd have a lousy control room and a lousy booth as well.

- Stuart -