New Design

#16

Man I would love to have the budget to do this but, I think the money would be better spent else where,
do you have some feed back on what you would do with the 2 leaf system , use existing wall or just build 2 more walls 2x4?

#17

do you have some feed back on what you would do with the 2 leaf system , use existing wall or just build 2 more walls 2x4?

Any way you look at it, the existing building wall IS your outer leaf. There's no getting around that.

The question is: How good of a leaf is it?

If it isn't all that good yet, then as eightamrock mentioned, your best bet is to "beef it up" by adding additional mass to it, which can indeed be done by inserting panels of OSB, MDF, plywood, drywall or fiber-cement board between the studs, pressed up against the existing "leaf" materials (with no air gaps trapped in between). Once you have enough mass on that outer leaf, then you need only ONE more leaf for each room, which is the inner-leaf. So you erect stud framing for that, then put enough layers of OSB/MDF/Plywwod/drywall/fiber-cement board on just ONE side of those studs, to get the mass you need for the second leaf.

So, you end up with just two leaves: the outer leaf, which is the existing shell of the building on the outer side of that stud frame with NOTHING else on the inner side of those studs, plus the inner leaf, which is a separate stud frame that has your materials also on only ONE side of it.

Two leaves, only two leaves, and nothing but two leaves. If you add yet another leaf to that system, then you DECREASE your isolation, especially in the low frequency end of the spectrum. With 3 leaves (or more) isolation might get better for the highs (which don't really matter that much), but will very likely get worse in the lows, such as kick drums, snares, toms, bass guitars, the low end of keyboards, etc.

In the reference section of the forum there's quite a bit of info on why 2-leaf is the only way to go, and why 3-leaf is a bad idea. Sometimes you can't avoid 3-leaf, and in that case there are ways you can compensate for the lost isolation, but in your case you have the option to do it right: you have a brand new stand-alone building that is purposed especially and only for your studio, so you can do it right: do a 2-leaf system, to get maximum isolation for minimum cost.

From your PDF layout, it looks to me like you have a 3-leaf system, and with a very small 1" air gap between the outer and middle leaf. That's not a good situation at all. You also have a note saying '2" air gap' on that wall detail, and although that might seem right from a construction point of view, it actually isn'0t correct from the acoustic isolation point of view. What you mean is that you have a 2" gap between those two stud frames, but since the framing seems to be 2x6 (which actually measures 1 1/2 x 5 1/2"), the actual "air gap" there is 5.5 +2 +5.5, which is 13". That's excellent.... for a 2-leaf system! But adding the 3rd leaf outside that, with just a 1" gap, is NOT doing you any favors. I didn't do the math, but I suspect you'd be losing a bit of isolation in the low end from that. My suggestion would be to re-design so that you only have a 2-leaf system, not a 3-leaf system. In other words, get rid of the framing and mass in between the actual building shell, and your rue inner leaf. That would increase your air gap by another couple of inches, and thus improve isolation even more. If you put that same mass (the two layers of drywall) on the inner leaf, you'd be increasing yet again, probably getting beyond what you need.

Your slab is your limiting factor, as Glenn pointed out. But since it is a stand-alone slab-on-grade (and therefore very well damped), plus the building is relatively far from places you might annoy, it's unlikely to be an issue. If your slab limits you to (for example) 55 dB isolation, that's already pretty darn good. You should then concentrate on maximizing isolation for the rest of the building. Your weak points will pretty much be doors, windows, and the HVAC system, as well as possibly the roof. Getting 55 dB isolation from HVAC isn't easy. Getting 55 dB from doors isn't easy. Ditto windows. It can be done, of course, but it requires attention to detail and careful planning.

So, with the above in mind, your current plans reveal a few issues that would need fixing in order to get you where you want to be.

Firstly, your control room is not isolated. It is built as a coupled leaf system, so you will only get maybe 35 dB from that. The slab simply doesn't play into this at all, since the walls and doors will give isolation that is far worse than the flanking limit of the slab. I'd suggest re-designing that as a proper 2-leaf system.

Second, you are missing a door from the bathroom/lobby area into the live room. Right now, you show only one door there, on the leaf that faces the live room itself, but the leaf that faces the bathroom/lobby has no door in it. It must have a door.

Third, you aren't showing any provisions for your HVAC system. I understand that this is just a first rough sketch of the overall isolation, but HVAC takes up a lot of space, and optimizing that should start early. It would be a good idea to start right now with planning for the exterior air inlet and outlet vents, the duct paths, the locations of the silencer boxes, the location of the air handler, and the locations of the registers that supply air into and remove air from the rooms. You probably don't need to do that in great detail just yet, but at least make some provisions for it now so it doesn't become a major headache later. And oversize all of that right now! Make the ducts and silencers way bigger than you think they need to be, to give you some "wiggle room" when it comes time to do the details.

HVAC is probably the single biggest "gotcha!" in studio design. Start roughing it in now, so it won't be such a huge problem when you get to detailing it later.

One more thing: You should take some time planning your control room layout now too, before you finalize the positions and sizes of windows and doors. It seems to me that the door from the control room to the lobby/bathroom area is too far forward (to close to the front wall of the control room). I'd suggest sliding it back as far as you can, towards the bathroom, so you have enough space for the front corner acoustic treatment in the control room. That can take up a lot of space, especially if you plan to flush.mount (a.k.a. "soffit mount"!) your speakers (which is highly recommendable!). The control room also doesn't seem symmetrical, which is vitally important. It looks like the window isn't centered in the front wall. I'd suggest that you get i better centered, and start planning (roughing out) control room acoustic treatment and interior, to ensure that you don't run into unexpected issues later. It's a nice size control room, so acoustic treatment shouldn't be as complicated as if it were a typical small home studio control room, but it will still need good planning and design to make sure that the acoustic response is good. As the saying goes; "The devil is in the details".

- Stuart -

#18

Thank You for your reply,
The 6th post shows a floor plan more along what your saying for the 2 leaf wall system, this was the original idea.
the only change in the wall system would be the CR air gap, I would look to skinny that up for space as I believe the low end will not be as much as an issue with Playback

I was going to just order the 3d door they say 56stc, and was going to use only 1 door to the CR and LR. Are these doors not as good as they claim? If I need to double door what doors or design would you suggest?

As for HVAC I have only though basics on this , was thinking mini splits , but could do what ever I like, the roof is a peak roof that has plenty of room, where ca I find info on this and what would be the best for my build?

The door to the CR should clear bass traps in the corner,

You are saying the CR rear wall needs moved back? The console will be facing the top of the drawing , the door is the rear of the room, I am at 22 feet front to back, and yes soffit mount is what I will be doing

#19

The console will be facing the top of the drawing , the door is the rear of the room, I am at 22 feet front to back, and yes soffit mount is what I will be doing

Ooops! I just noticed that I had your CR figured totally wrong. I thought (due to not paying attention.... :roll:

) that you were planning on setting it up "width-ways", with the mix position facing the window, but I just saw your sketch back on the previous page showing that you are planning to set it up "lengthways", with the window on the left side wall. That's actually the better layout for your room, so apologies there for not seeing that earlier, and making bad suggestions... (That'll teach me to check threads better before replying...)

the only change in the wall system would be the CR air gap, I would look to skinny that up for space as I believe the low end will not be as much as an issue with Playback

Walls are two-way, not one-way, and in fact the entire studio is really a single "system", where all parts work together and interact to some extent. So playback might not be an issue, with little bleed from the speakers into the live room or elsewhere, but the wall goes the other way too: bleed from your drums (and other loud instruments) getting into the control room. Personally, I like to track in an environment where the only thing I can hear is the sounds coming through the speakers, nothing at all coming through the walls. I find that it makes it easier to set up mics properly, EQ well, set dynmaics, etc. If there's bleed coming through the walls/windows/doors, I find it distracts me from that, and I have a hard time telling if what I am hearing is the clean sound from the speakers, or the sound coming through the walls. That's more of a personal issue, sure: some engineers don't mind bleed at all, and can track just fine with the doors wide open! So that might or might not be an issue for you. But even so, it would be good to build the CR and LR for similar isolation levels. Even if you expect to only ever listen at 85 dBc in the control room, I'll bet that you (or someone else) will occasionally jack that up considerably, to "check the low end", as the euphemism goes.

Now, if the only change from that early diagram to what you are planning right now is a smaller air gap in the CR walls, then you do, in fact, have a 3-leaf system for several parts of your design, which implies the decreased in isolation that I mentioned before. If you build a 3-leaf wall, it will always have LESS isolation than the equivalent 2-leaf wall of the same total mass and thickness. It's a principle of physics (and acoustics). It isn't intuitive at first glance, since the natural assumption is "If one leaf is good, and two leaves is better, then three leaves is better still", but that actually isn't true.

I'd suggest that you take a look at these threads, to see what I'm talking about:

What is "room-in-a-room" construction?

What is MSM? How does it work?

Also, reducing the air gap in a wall doesn't just reduce isolation: it also changes the isolation profile. Meaning that most of the decreased isolation will be in the low frequency end of the spectrum, which arguably matters more than the mids and highs. There won't be much change in mids and highs, but there will be in the lows. Walls are tuned systems, and changing the parameters also changes the tuning. Reducing either the mass or the air gap (or the amount of insulation in the air gap), pushes the isolation curve up the scale.

I was going to just order the 3d door they say 56stc, and was going to use only 1 door to the CR and LR. Are these doors not as good as they claim?

Careful with STC ratings! That's not a good way at all of figuring isolation for studios. Fine for offices, schools and houses, where the main issue is mid-range frequencies. Not fine at all for recording studios, where the main issue is low frequencies. STC does not take low frequencies into account at all. Completely ignores them.

This thread explains that in more detail:
Why STC is not a good way of measuring studio isolation.

So a single door rated at 56 STC (which would be a really tall order anyway!) would likely not achieve what you are looking for. In addition, if you don't complete the outer-leaf around the LR, then you damage your isolation once again. A studio wall is an MSM system (see link above), and for maximum performance both leaves need to be complete air-tight shells. If you leave a doorway in there, then the leaf is not complete, and not sealed. That leads to reduced isolation.

If I need to double door what doors or design would you suggest?

I'd suggest doing it like this:
site built door for high isolation

You can, indeed, get high isolation like that. With a pair of doors, enough mass on each, and enough distance between them, then isolation of 50 dB or more is very doable.

As for HVAC I have only though basics on this , was thinking mini splits , but could do what ever I like, the roof is a peak roof that has plenty of room, where ca I find info on this and what would be the best for my build?

HVAC is a big part of studio design, and often left to the last minute. So its great that you are already thinking about that.

However, mini-split systems are only half of the solution. They take care of the H and AC part, but do nothing for the V part: Ventilation. Mini-splits do not ventilate. They only heat, cool, and circulate air. So you need ducts, silencers, and registers to get fresh air in and remove stale air. That's also a big deal, if you are aiming for high isolation for your studio. You can't just chop a couple of huge holes in the wall and poke ducts through! That would do serious damage to your isolation. So you need to put the complete system in place. You might find these useful, as they cover many of the things that you'll need to know when you start designing that part:
Why your studio needs proper HVAC.

Studio HVAC: All about mini-split systems, HRV's and ERV's

The door to the CR should clear bass traps in the corner,

I'm not convinced!

You'd be surprised how big bass traps need to be, especially the most effective (but least efficient) ones, based on porous absorption and "hangers" (sometimes also referred to as "waveguides"). Id suggest moving it over as far as you can, towards the center of that wall.

- Stuart -

#20

Thank You for taking the time to reply all great info, I will post the newest design.
I was trying to avoid 2 doors, I see lots of studios with just one nice big heavy door, How are they doing this with one door? There must be a design with a door way / small hallway with neoprene etc to seal the leafs but only use 1 door still?
Also, can you share any AC silencer vents and designs that work good?

#21

If anyone can give me direction on if I do need 2 doors or If there is a design to use only one door?
Also, a design or product for vac silencers? These are the last few things I need before I start my build?

#22

1970428scj wrote:Source of the post If anyone can give me direction on if I do need 2 doors or If there is a design to use only one door?
Also, a design or product for vac silencers? These are the last few things I need before I start my build?

There is a fantastic book, Recording Studios: Build it like the pros, by Rod Gervais. In there he describes the implications of 2 doors vs a single "super door". Its definitely worth a read before you start building. So you could do either as long as you spec your isolation needs and build it to that spec. I personally will be doing single doors that all enter into an airlock, this meets my isolation needs.

https://www.amazon.com/Home-Recording-Studio-Build-Like/dp/143545717X

#23

...as long as you spec your isolation needs and build it to that spec.

Exactly! That's the key point. First priority is to decide on what level of isolation you need, then design and build the entire studio (all of it: Floor, walls, ceiling, doors, windows, HVAC, electrical... everything) to that level. Which is what you did!

Rod's "superdoor" is an option, certainly, as long as that's enough isolation for you... and as long as you can build the massively tough framing to support it! That door is heavy, and as Rod himself points out, needs some really heavy-duty support: framing, hinges, jambs, automatic closer, seals, etc. Having hundreds of pounds of mass swinging around all by itself is rather dangerous, so it MUST be built right. It also needs more than one person to install it (5 or 6 strong guys, to do it safely). Getting that thing plumb and square, ain't easy.... As long as you have the skills, tools, and manpower to build it, hang it, and maintain it, then it is an option. Personally, I don't recommend it because most home studio builders don't have those: necessary skills, tools, and manpower. A pair of more reasonably sized doors is easier to do, more forgiving, and can can be done by one or two people with average skills and tools.

A single-leaf door is, of course, governed by mass law. So calculating the mass you need to get the level of isolation you want is very simple.
The general Mass Law equation is equation is:

TL(dB)= 20log(MF) -47.2

Where:
M is the surface density of the panel (mass per unit area (kg/m²) ), and
F is the center frequency of any one-third-octave measurement band

So pick a bunch of frequencies, pick the mass per unit area of the door you have in mind, and you get the isolation at that specific frequency.

Or if you just want a rough estimate of the overall isolation of the door, not worrying too much about frequencies, then you can use the simpler generic equation:

TL = 14.5 log (M * 0.205) + 23 dB

Where: M = Surface density in kg/m2

Here's a graph that makes it even simpler:

That comes from the famous Marshall Day Acoustics paper on isolation, in the section about single-leaf barriers.

So, for example (from the above graphs), if you have a solid oak door 1 3/4" thick (4.5 cm), that would get you about 20 dB of isolation, according to the experts at Marshall Day Acoustics (and also according to Mass Law). If you increase that to a 2 1/2" (6.5 cm) thick heavy wood door, you would get closer to 30 dB of isolation. If you could somehow figure out how to make a door from 4" bricks, that would get you around 45 dB isolation. That's about as high as you can get realistically, from a single-leaf door. (And I use "realistically" in the extreme there: a 4" brick door is way out at the edge of "realistic"!). The door made from the 2 1/2" thick heavy wood, has a surface density of around 70 kg/m2, and a typical studio door is probably close to 2 square meters, so the door would weigh about 140 kg (around 300 pounds). The theoretical 4" brick door has a surface density of around 215 kg/m2, so the door would weigh about 430 kg (around 950 pounds). Supporting, opening, and closing a door that weighs nearly a thousand pounds, is a big deal. That is some framing! And the hinges? I'm not sure about what hinges you'd use to hang a thousand pound door....

Here's an interesting paper from the BBC, where they tested doors made from several exotic materials ("lead core", "bitumen core") in their laboratory, along with comments and results:

BBC-1994-14-isolation-doors-part-1.pdf: (1.07 MiB) Downloaded 465 times

BBC-1994-14-isolation-doors-part-1.pdf: (1.07 MiB) Downloaded 465 times

And here's part 2 of that paper, which is all about the other major factor in isolation doors: the seals. Very interesting paper! It clearly highlights the reason why you'll see seals mentioned ad-naseum on this forum. Without proper seals, your door is pretty useless, no matter how well it is made, or how heavy it is.

BBC-1994-15-isolation-doors-part-2.pdf: (1.11 MiB) Downloaded 534 times

BBC-1994-15-isolation-doors-part-2.pdf: (1.11 MiB) Downloaded 534 times

Anyway, getting right down to it: first figure out how much isolation you need, then see what type of door can provide that. If you are OK with around 30 to maybe 35 dB of transmission loss (isolation), then a massively heavy single-leaf door will do the job, as long as you can figure out how to design and build the massively tough framing system needed to support it without bending, twisting, and/or warping as the door is opened and closed (also assuming that your floor is rated to handle the rather large point loads under the door area). If you need more isolation than that (or if you don't have the skills, equipment, and manpower to pull it off), then a pair of lighter, simpler, back-to-back doors is probably your best bet.

As with all things related to studios, it start with the numbers: figure out how much you need, in decibels of TL (never STC!), then figure out how to achieve that, within your budget and skill set.

- Stuart -

#24

Also, can you share any AC silencer vents and designs that work good?

It's not that easy, unfortunately! Your HVAC system should be designed specifically for your room. It needs to move the right volume of air, at the right rate and speed, for your specific room. It needs to deal with your specific latent heat and sensible heat loads, and your specific climate.

There's some general "rules of thumb" that can help you get in the ball-park: for example.
- Aim for at least 6 and preferably 8 "room changes per hour". To figure that out, calculate the total volume of air in your room, and multiply by 6 (or 8 ). That's how much air you should recirculate through your room, so your HAVC fans and/or air handler should be able to do that. Normally fans are rated as "Cubic Feet per Minute", so divide the above number by 60 to get that. But fans are also usually rated in free air, without any resistance to the flow, so you also need to take into account the "static pressure" of your ducts and room. The manual for your fan and AHU should tell you what the real rate is for each specific static pressure. Often it's in the form of a graph, or a table.

- Aim to replace about 20% to 40% of that recirculating air with fresh air coming from outdoors, and dump the same amount of "stale" air to the outside. So, for example, if you figure that your Control Rooms needs 400 CFM, then you'd need to bring in about 80 to 160 CFM of fresh air, and mix that with the recirculating air just before it all goes into the AHU (Air Handler Unit).

- Size your ducts so that the air flow speed is less than about 1000 fps (inside the duct), if possible. Sometimes that isn't possible, but its a good number to shoot for

- Size your registers so that the air flow speed through them is less than 300 feet per second (fps), maximum, and preferably less than 200 fps. If the air is flowing too fast, it creates hissing and rumbling noises that will get into your mics in the LR, and also interferes with your ability to track and mix well in the CR.

- Design the silencer boxes to give you the same level of isolation as the walls. In other words, if your walls are designed to give you 50 dB of isolation, then the HVAC silencers should be designed to give you something similar. They also need to reduce the flow velocity from the 1000 or so FPS in the ducts, to the 200 or so at the registers. That implies greatly increasing the cross-sectional area of the air path.

- Take into account all the sensible heat loads in each room when figuring the capacity your AHU will need. That includes equipment, amps, lights, computers, hard drives, people, and anything that those people might bring with them (eg, hot food, hot drinks) or plug in when you aren't looking. Just the people themselves can put out a surprising amount of heat, especially when jamming hard and fast.

- Also take into account all the latent heat loads, including the air humidity, people, and things they might have with them that could produce moisture (damp towels, wet clothing, etc.) Your AHU will have to deal with all of that moisture in the air BEFORE it can actually start cooling the air.

- Keep the duct fans and AHU outside your isolation shell as far as possible. Fans make mechanical noise, as well as the actual air movement noise. Use low noise fans, sure, but even so they still make a noise. If your studio is well isolated, then even small noises become noticeable, and annoying.... and will get picked up on your mics in the LR. Ideally, put the duct fans on the outside of the building, and the AHU inside the building but outside the isolation shell.

etc.

Rules of thumb like that can get you well on the way to designing your HVAC system properly. There are several threads here on the forum that provide more detailed info, and many build threads where forum members have worked through the entire process showing how they did it in their own studios, and what the outcome was.

- Stuart -

#25

Hi Thanks for reply, I do have Rod's book and refer to it often, In my 6th post I show 2 doors (load in) to live room. The front door is my air lock, I was planning to use a 3d door, 350lbs, claimed 56stc I understand etc is simple voice and not music, But my thoughts were to have the air lock and this creates the 2nd door. https://acousticgeometry.com/products/s ... roof-door/

My isolation needed is max but then there is a budget so it really comes down to budget.
I am not cutting the slab and doing iso slabs for each room, so that stops me at 56stc? Therefor if I can get 56stc from the walls, ceiling and doors I would be very happy,

as for HVAC, yeah this is a hard one, in my last studio this was not correct and was a hot box of a problem. I have a bunch of analog tube gear, tape machines and a vintage API I leave on.
I am leaving for a motorcycle trip in a few hours , Have Rod's book and will dig into this more.
Thank you all

#26

If I were to isolate the slab, what would be the best way to do this? It is a 40x30 garage stand alone building,Base slab is 5-6" thick. In order to do this I would need to cut the to separate the CR and LR, then cut around the footings of the exterior wall for the CR?
This seems risky the footings of the exterior walls are depending on the rest of the slab? This is gonna kill my budget pretty quick as this is a ton of work.
Structural engineer would probably be needed. Can I simple isolate the floor by pooring another slab over the base slab and use microlight and sound board between? I posted a diagram on page 1 of this thread. This is what my friends pro plans show. Im sure this idea comes down to what the existing slab can handle weight wise.

another question I have is soffit mounting.
I will be soffit mounting the monitor system, my question here is, If I build a 2 leaf system for the CR then I frame the soffit, sheet the soffit this becomes a 3 leaf system, on a friends pro studio plans this is the way its done, but everyone here says no 3 leaf ??
Thank you all for your input

#27

so the poured extra slab - you could do this to create a "floating floor", as cutting slabs which have (or will have) load bearing walls would require additional footing work anyways. not sure about the products used in your diagram but i have used Kinetics Noise and Mason Industry products. for your situation the pad approach is probably more workable. use the KN RIM (pads + insulation) under a plywood layer with the concrete pour on top. you can call the KN folks who can assist with getting the right product. we used RIM in the Red Bull studio to float 3 large slabs (12" thick aerated concrete) - about 15 tons or so. and they worked perfectly.

#28

What are options for cable trough, Console to rack, console to tape machines, console to inputs in Live Room?

#29

several options - conduits between room - up and over and down, you could leave some of the new poured floor recessed as pathways (like a 2" deep channel which you could cover with the finish flooring), conduits in-room via the ceiling soffits, etc.

#30

Can a trough be made in the RIM floor system? I have tape decks, PT rig, fx rack, and xlc input lines from each room. Is there any example design drawings

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