Quick overview of strategy - advice on custom doors - Melb

[sdog]

Hi All,

I am formulating a design for an apartment that I move into in 2 weeks.

The room is very small (2000(w) x 3400(l) x 3400(h)), on the ground floor of a rendered brick art deco apartment, with neighboring apartments above and to the side. All the room walls are rendered brick, the ceiling is quite high and thin (as I can clearly hear the neighbors walking along their floorboards). The floor is floorboards on stumps.

I have done enough research to believe I am on the correct journey, however if there are any glaringly stupid statements below(lets call them ideas at this stage), give me a slap! My number one priority is to make it as silent as possible. There wont be any desks, racks or any other studio hardware other than a computer, monitors, recording gtr and vox.

I WILL HAVE SOME QUESTIONS AT THE END OF THIS POST, however for transparency here is my thinking

"Room in a Room" - studs 70mm x 35mm
external width = 1996mm, external length = 3000, external height = 2400
walls and ceiling - 16mm Fyrchek > R2.0HD Knauf Earthwool High Performance Batts 75mm > 16mm Fyrchek > Green Glue > 16mm Fyrchek
floating floor - medium density rubber > R2.0HD Knauf Earthwool High Performance Batts 75mm > Plywood > Green Glue >16mm Fyrchek > Green Glue > Plywood
Air Flow - will utilise the space either on top of the inner room ceiling or the 400mm in the length to build ventilation vents with appropriate lengths, bends and soundproofing materials - using large exhaust fan with speed control. i.e. intake and exhaust vents.
door - ????? Although I have chippie mates that will assist me (read: them doing the work) in making sure the build is on point, I wouldnt rely on them building a door that meets the spec of an airtight environment.
other stuff - sealant everywhere, sparkie to hook up all mains/lighting/fan

OK, how am I going so far? Again, it is a tiny room and I sometimes think its overkill (my wife said she would collect egg cartons.....too old a joke??), but I do need a space to work in this apartment.

So the questions I have for fellow Aussies
- who would you recommend to build a customised door/frame (preferably Melbourne)
- is there anything that I can strip out of this "proposed build"
- is there something that I have royally screwed up - tell me, I can take it!

Ideally I would like change out of $6000, but if it takes 3 more bottles of glue, better batts etc....I would prefer to get it correct!

Be gentle and thanks

NOTE: Designs/plans will follow this consultation.

[Soundman2020]

Hi "sdog". Welcome"!

The room is very small (2000(w) x 3400(l) x 3400(h)),

What is the purpose of the room? Is this a control room, live room, isolation booth, tracking room, vocal booth, rehearsal room, etc.?

The floor is floorboards on stumps.

"Stumps"? I'm not familiar with that term in reference to building construction. Please explain...

My number one priority is to make it as silent as possible.

You need to put an actual number to that, in terms of how many decibels of isolation you are shooting for. What you call "totally silent" I might consider "unacceptable loud". OR vice versa.

walls and ceiling - 16mm Fyrchek > R2.0HD Knauf Earthwool High Performance Batts 75mm > 16mm Fyrchek > Green Glue > 16mm Fyrchek

But you said you already have existing walls there ("All the room walls are rendered brick)", which is your outer leaf, yet here you are talking about adding another TWO leaves?? That would be a total of three leaves, which is pretty lousy for low frequency isolation. That would be a "room in a room in a room". Not what you want.

floating floor - medium density rubber > R2.0HD Knauf Earthwool High Performance Batts 75mm > Plywood > Green Glue >16mm Fyrchek > Green Glue > Plywood

Nope. Bad idea. Here's why: http://www.johnlsayers.com/phpBB2/viewt ... f=2&t=8173

Air Flow - will utilise the space either on top of the inner room ceiling or the 400mm in the length to build ventilation vents with appropriate lengths, bends and soundproofing materials - using large exhaust fan with speed control. i.e. intake and exhaust vents.

First you need to do the math! You need to figure out your room changes per hour, convert that to air flow rate (CFM), use that and the maximum allowable air flow velocity to figure out your duct sizes and register areas. Then you design your silencer boxes, figure out the total static pressure from the system, and look for a fan that is able to move that volume of air at that speed into that static pressure.

It's a lot more complicated than you are allowing for. And that's just the ventilation part: you also need to figure out the sensible heat load and latent heat load in order to determine what size AHU you will need (in terms of BTU/Hr), to keep the temperature and humidity under control.

Again, it is a tiny room and I sometimes think its overkill

Small rooms need just as much isolation as large rooms, and they need MORE treatment! The smaller the room, the more treatment it needs. So no, it isn't overkill. It's probably "underkill", to coin a new term!

It all starts with that magic number: How many decibels of isolation do you need?

- who would you recommend to build a customised door/frame (preferably Melbourne)

Any good carpenter (finish carpenter, not framing carpenter) should be able to do that. I designed a place for a customer in NSW recently, and his carpenter did a superb job on the doors and frames. He's a long way from you, though! But any good carpenter can handle that. It's not complicated: just needs precision and careful workmanship.

- is there anything that I can strip out of this "proposed build"

Yes: the unnecessary leaf, and the floating floor, at least. Maybe other stuff too.

- is there something that I have royally screwed up - tell me, I can take it!

You have not allowed for HVAC. That's rather important, if you'd like to stay alive inside your room! Sometimes people think HVAC is a luxury for a studio, but in reality it is a basic necessity. It is absolutely essential. Think about it: You'll be sealing the room air-tight, twice over, perfectly hermetic. No way for air to get in or out. But you sort of do need air! I'm betting that you are like most people, and you like to breathe a few times per minute... Each time you inhale, you use some of the oxygen in the air, and then you exhale CO2. Since the room is sealed, there's a limited amount of oxygen in there. Each time you take a breath, the concentration of oxygen goes down and the concentration of CO2 goes up. So does the humidity, because you also exhale water vapor. Before very long, the air gets rather unpleasant in there. Then it gets dangerous. Then it knocks you unconscious. Then it kills you eventually. Not from lack of oxygen, which is what most people think will kill you, but from excess CO2. You can actually die from asphyxiation when there is a totally normal percentage of oxygen in the air, but there's way too much CO2. There was an article in the paper a day or two ago, about an amorous couple who used their car for some "time together", with the windows closed and vents closed, and managed to kill themselves from excess CO2, produced by their ... ummm ... "strenuous activities" inside the car...

So you need to rethink HVAC.

Ideally I would like change out of $6000,

the HVAC system will take a fair chunk out of that. I'm not sure how expensive min-split systems are whee you live, as prices vary wildly in different locations around the world, but I'd estimate something in the range $500 to 1k. Plus installation, ducts, fans, duct liner, silencer boxes, registers, etc. It will be probably be getting closet to 2k, by the time you are finished.

There's probably other things you are missing too, but that's the biggie.

- Stuart -

[sdog]

This is fantastic Stuart and thanks so much for taking the time.....this questioning and advice is exactly what I desperately need. I literally am 2 weeks into this journey and am a bit confused (obviously!!)

What is the purpose of the room? Is this a control room, live room, isolation booth, tracking room, vocal booth, rehearsal room, etc.?

It is for recording vox, guitars and pre production stuff (e.g. arrangements, composition).

"Stumps"? I'm not familiar with that term in reference to building construction. Please explain...

I think you may call them joists,

You need to put an actual number to that, in terms of how many decibels of isolation you are shooting for. What you call "totally silent" I might consider "unacceptable loud". OR vice versa.

I really dont know how to answer that. The apartment above has a baby, so ideally it would be silent enough not to have the mother knock on the door . In a best scenario, I could crank up the guitar amp with minimal noise escaping, however due to the space/location/size I fully understand I will need to be realistic; e.g. choose my times of the day for extreme loudness, use iso cabs etc.

Nope. Bad idea. Here's why: link to floating floor post

Yes, I have read that post 10 times or more and honestly still don't understand my best option. I did speak to an studio acquaintance and he reinforced my belief that I need a floating floor....but, hey.....if you say so GREAT!!! So do I simply need some neoprene, plywood etc?

It's a lot more complicated than you are allowing for. And that's just the ventilation part: you also need to figure out the sensible heat load and latent heat load in order to determine what size AHU you will need (in terms of BTU/Hr), to keep the temperature and humidity under control.

Yes you are right, I know nothing regarding this stuff. Again, it is a tiny room and I have done some calculations: 7.0 cfm per minute, 2,092 BTU/hour or 613 watt.
But as to how to design/implement a solution for these figures I haven't got to yet....was hoping to get all the other requirements first before I tackled this.

It all starts with that magic number: How many decibels of isolation do you need?

I can hear your frustration...., hey, I'm frustrated with myself I'm embarrassed to admit I do not know. I do know that if I could record "screaming rock" vox, track a 100w dirty guitar amp without annoying the neighbours........then I would be in heaven....what decibel number is that?

Any good carpenter (finish carpenter, not framing carpenter) should be able to do that

Great news!

....produced by their ... ummm ... "strenuous activities" inside the car...

Bwahaha, well if there is a way to go out!
I hear you and understand. I wont underestimate this in the design. Again, and maybe foolishly, except for some basic calcs and the understanding that I need to do HVAC correctly, I was leaving this aspect of the design to last. I have sourced (read: googled) appropriate exhaust fans, ducts, vent specs and designs etc, but really wanted to understand just how much of the room I had left after I had designed the "room in a room".

HVAC... It will be probably be getting closet to 2k, by the time you are finished.

Yes, I understand.

Again Stuart, thank you. Can I just ask you these questions in summary

1. The floor - I just need to make it airtight with rubber, plywood and sealant etc? (ie no floating floor). This is efficient enough to eliminate my same floor neighbours from complaining?
2. The walls - just put more mass on the existing brick walls directly? What would that look like?
3. With a thin ceiling above, I assume that I stick with the original build concept, leaving a 20cm space between the true ceiling and the room?

Cheers
S

[Soundman2020]

This is fantastic Stuart and thanks so much for taking the time.....this questioning and advice is exactly what I desperately need. I literally am 2 weeks into this journey and am a bit confused (obviously!!)

Acoustics is a BIG subject! Much bigger than I ever expected when I first started looking into it, a couple of decades ago. It took me a while to learn enough that I could realize I actually didn't know anything!

Seriously, it does take a while to get your head around some of these concepts. They seem so anti-intuitive at first. For example, who would think that putting an extra layer of mass in the middle of a wall cavity would make the isolation WORSE, not better? Not intuitive at all, but true...

So if you are only a "bit confused" right now, after two weeks, then hold on to your hat, as the ride is about to get interesting!

It is for recording vox, guitars and pre production stuff (e.g. arrangements, composition).

OK, so its basically a tracking room, but you won't be mixing in there: you'll take your tracks to some other studio to mix?

I think you may call them joists,

I really dont know how to answer that. The apartment above has a baby, so ideally it would be silent enough not to have the mother knock on the door . In a best scenario, I could crank up the guitar amp with minimal noise escaping, however due to the space/location/size I fully understand I will need to be realistic; e.g. choose my times of the day for extreme loudness, use iso cabs etc.

I could guess at the number for you, based on experience, but I might be wrong. The only way to find out for sure is to get a hand-held sound level meter, and measure. They are not expensive: a decent one costs around US$ 100. (Stay away from the cheap Chinese toys that cost under US$ 50!!!! Those are useless).

With you meter, find a place where you think the sound level is "quiet". Acceptably quiet. The sort of ambient sound that mom-and-baby would find really pleasant. Measure that level, with your meter set to "C" weighting and "Slow" response. Note it down. If you aren't sure, try several places that you think are suitably quiet, and note down all the numbers for those.

Now go to the place where you want to set up your studio, and do what you'll normally be doing in there, as loud as you'd ever expect to be, and measure that level too. (Also "C" and "Slow"). Do it several times, in several different ways, with several different "things" that you'd typically be doing.

You have now answered the two most basic questions: 1) "How loud are you?" and 2) "How quiet do you have to be?". The difference between those two numbers is your goal. That's how much isolation you need. So for example, hypothetically, let's say you measured the "loud" level at 95 dBC and the "quiet" level at 45 dBC. 95-45=50, so your isolation goal would be 50 dB.

I did speak to an studio acquaintance and he reinforced my belief that I need a floating floor....

You may well need a floating floor, but wood framing on rubber pads with plywood on top is not a floating floor! It just isn't. You need much, much more mass on the floor to ensure that it floats properly.

Here's just one of the issues, and I'll keep it very simple. Let's say you hypothetically have a room with a 10m2 floor. So you do all the math and figure out that with a load of 100 kg your rubber pads would just float the floor perfectly. So you do some research and find that 10mm thick plywood weighs about 5 kg/m2, so two layers would make it 10 kg/m2, and your floor is 10 m2... Perfect! That's 100 kg/m2! So you build your floor like that, and it does indeed float wonderfully!... until you step on it . Lets say that you weigh 80 kg. So with you standing on the floor, now there's a load of 180 kg on the rubber pads, instead of the 100 kg they were designed for, so they "bottom out", and the floor does not float any more... Ooops!

So you figure: "OK, then I'll allow for that in my calculations! I'll design it for 180 kg,and use more rubber pads! After all, I only need it to float when I'm in there!". Yep! Excellent idea. Great. So you build it like that, and it does in deed float just fine when you are in there. It doesn't float when you are NOT in there, because there's not enough weight on the pads to compress them enough, but that's fine, as there's nothing going on in there when you aren't standing on the floor. So great! Wonderful! Your floor floats with you on it! But then you need to drag in a 60 kg amp, and 10kg of cables, and a 5 kg electric guitar, and a 2 liter bottle of coke, and your 65 kg girlfriend wants to be with you while you play. Ooops! Now you have 323 kg of weight on those pads that are designed for only 180, so once again, it does not float.

"Well", you figure, "Then I'll design it for 323 kg! Problem solved!" So you do that, and it does indeed float at 323 kg. But what happens the day you go in there without your girlfriend, amp, and coke, and you just want to record your own vocals? Well, now the load is only 180 kg again, and it is on pads that don't float until there's 323 kg resting on them, so your floor does not float...

I think you can see where this is going. This is one of the major reasons why light-weight plywood decks cannot be used as floating floors. Even small changes in the load will kill the isolation. It is impossible to account for all situations.

The correct way to float a floor is with a MASSIVELY heavy deck. For example, 15cm thick layer of concrete. A 10m2 square floor done like that would weigh over 3,000 kg, so the weight of you, your amp, your girlfriend and the coke is negligible. It does not matter what combination of those things you use, you are only changing the total weight by a very small fraction. Maybe 5% or so. That's no big deal, and it does not cause the floor to stop floating.

That's why studio designers have to laugh at the videos on YouTube of people enthusiastically plonking down rubber pucks and framing, putting a single layer of plywood on top, and thinking they did something fantastic.... In reality, all they did was to create a resonant cavity that will trash their isolation as it will ring loudly at its resonant frequencies, amplifying them... and it will also trash their room acoustics.

And that's just one of the reasons!

So if you do need to float your floor (and you might) then be prepared to put some major mass on it, at least a few thousand kg, and be prepared for the type of isolation mounts that are needed to float that... and the cost! And also the structural modifications to the underlying floor, to be able to support all of that load...

So do I simply need some neoprene, plywood etc?

See above...

The actual answer depends on the "number": How much isolation do you need? If you figure out that you need 35 dB of isolation, that's great! You can do that without a floating floor. But if you need more than 60, then you have no choice. The area in between is gray....

Again, it is a tiny room and I have done some calculations: 7.0 cfm per minute,

I think you messed up the calculation someplace. 7 cubic feet per minute would be about right for a shoe box... (OK, that's an exaggeration: it would be about right for something the size of a small refrigerator. Even a vocal booth will normally need something like 50 to 100 CFM, and a small live room might need several hundred.

Start with your room volume, in cubic feet. Assume 6 room changes per hour. Work it from there...

But as to how to design/implement a solution for these figures I haven't got to yet....was hoping to get all the other requirements first before I tackled this.

It would be nice if you could leave that until the end, but unfortunately you can't. Designing a studio, even a simple one, needs to have all of the parts designed at once, as they all have to fit together and work together. You'll need silencer boxes for your HVAC, and they are quite big. So you need to make space for them, either inside the studio itself, or inside the walls, or above the ceiling, our outside. So you need to come up with the plan for that at the same time that you are designing the walls, floor, and ceiling.

I do know that if I could record "screaming rock" vox, track a 100w dirty guitar amp without annoying the neighbours........then I would be in heaven....what decibel number is that?

I wish I could put a number to that, but it would just be a wild guess. The amp alone could probably put out 110 dBC, or more, if you push it hard. Your screaming could another couple of dB to that, maybe. So perhaps 112 dBC on the "how loud" side. But what about the "how quiet?" side? That's subjective, and needs to be measured. You'll need the help of your neighbors here, since they are the ones who will judge what "quiet" means to them.

1. The floor - I just need to make it airtight with rubber, plywood and sealant etc? (ie no floating floor). This is efficient enough to eliminate my same floor neighbours from complaining?

There are options,but first we need your "magic number" to help decide which one is best for you. Worst case, you would need to float your floor, and that can eat up serious amounts of money.

2. The walls - just put more mass on the existing brick walls directly? What would that look like?

The existing brick walls are fine: It would be good if you could render those (plaster them), or at the very least paint them with masonry sealer. Brick is porous, meaning air can move into and out of the surface, so you need to seal that up. But you don't need to add more mass to the brick walls. They are plenty massive as they are, and they can be your outer-leaf. So you just need to put up wood framing a few cm away from the walls, not touching them, and put drywall (p0lasterboard) on only ONE side of that framing (never both sides), plus insulation in the cavity.

3. With a thin ceiling above, I assume that I stick with the original build concept, leaving a 20cm space between the true ceiling and the room

Build your new inner-leaf ceiling on top of those new inner-leaf walls, also such that the ceiling ONLY rests on the new walls, and does NOT touch the old walls or ceiling.

You have now correctly built a "room in a room".

There might be more to it than that, such as probably needing to "beef up" the original ceiling above you (the floor of the room above) with more mass, and seal it, but the above outline is basically what you need to do.

- Stuart -

[sdog]

Stuart, you are a legend.

Thanks, leave it with me and I will return later in the week with all the numbers!!

dog