Basement Studio Build

Hello there, My name is Greg Mann, from Ogden Utah USA, and I have been following this site for a couple of years now and appreciate all of the information. I just bought a new home and I am wanting to build my recording studio in the basement and move my operation from my parents basement. I plan on recording drums, electric/bass guitars, acoustic, strings, vocals, etc. in the studio space. I want to keep sound out and in, in especially while recording drums. The neighbors on both sides are about 20 to 30 feet away, and we have no back yard neighbors. It's a pretty quite neighborhood and I'd like to keep it that way, even while I'm producing a band;) I am wanting to build the studio in such a way that if we ever do sell the house, it can easily be converted into two normal bedrooms. As you can see in the diagram the control room is 10ft by 10ft with a height of 7ft 7.8 inches (not exactly the best dimensions I know, but that's what I have to work with). I know that the room wasn't quite drawn like a 10 by 10, but that's what it is:) The left wall of the control room already exists and is the load bearing wall. The control room will be studded out normally, to the basement cement walls, because most of the mic'd recording will be occuring in the tracking area. The window will be left in place just in front of the desk and bass traps will be placed in each corner to to help avoid 90 degree angles. The glass doors between the rooms will be my only sight line to the artist tracking. There is also a heating duct running from front to back in the control room, which I will be ducting around. The utility room is also behind the control room, with a hallway in-between. The tracking area is what I have the most questions on. It is 13ft by 10ft by 7ft 7.8 inches high, and will be built with a room within a room design. If I stud out to the walls and drywall up to the floor joists above, then build a room within that, will I be creating a third leaf? A couple of ideas are; 1. Just build one room and do staggered studs in the walls to keep sheetrock on both sides from being connected to the same studs, reducing noise tranfer, also the walls would be built a coupld of inches away from the outside basement cement walls to create an air gap. I would then do some type of floating ceiling to try and disconnect the ceiling from the floor joists of my kitchen above. Any ideas on how I can do a floating ceiling properly? 2. Build one room studded away from the outside walls, but do a double stuff design instead. This would be achieved by building two stud walls parallel to each other but not quite touching, filling them with insulation (insulation recommendations? I hear rockwool is good) and putting drywall on each side basically creating a super thich wall with two stud walls in between. Then I would do a drop ceiling.I realize that I will lose a couple of inches with the drop ceiling, but I want to decouple the room from the kitchen above. Once again, any help would be great in this matter especially. Which of these two room within a room designs would be best for keeping sound out and in? Once again, this will be an all-purpose tracking area. Blankets on the walls, foam, recommendations? Do I need to secure the joints with green glue to get this room tight? Any recommendation on HVAC design? The home currently has a swamp cooler and furnace. Any help in the design of this construction will be greatly appreciated. Please keep in mind that this is a home studio and any recommendations for more inexpensive products would be greatly appreciated because my budget is huge for this. The basic drawing of the studio is found below. Thanks for your time! Regards-Greg Mann

Hi Greg. Welcome! Please read the forum rules for posting (click here). You seem to be missing a couple of things! :) There are several red flags with the plan you described, but unfortunately I have to run right now, and wont be back until late this afternoon. In the meantime, maybe you could use the forum "search" feature for both "MSM" and also for "room ratio", and take a look at some of the stuff you find. The biggest red flags are your control room dimensions and your isolation plan. The search feature is not very good, and will turn up a lot of stuff that is NOT applicable to you, but if you work through some of the threads, you'll probably find the basis for what you need to know about those. If not, I'll try to reply in more detail tonight. - Stuart -

Stuart, thanks so much for the quick reply. I originally didn't see where I could add my location. That has been fixed:) I understand that the space is not ideal, I am just trying to do the best i can with what I've got. How would you suggest changing the design, both in layout and room-in-room wall construction. Should I not leave an air gap in between the cement basement wall and the tracking area exterier wall? Would double stud construction not be the best option for the space I have? Once again, I'm trying to keep sound in and out. -Greg

Hi again, Greg.

I originally didn't see where I could add my location. That has been fixed:)

Yup! That was it! :) OK, I have a bit more time right now, so let me break it down a bit:

I plan on recording drums,

Acoustic or electric? Acoustic drums are the loudest of all instruments, and the hardest to isolate. You should find out what the legal limit is for noise in your area: call your local municipality and get a copy of the noise regulations. That's your goal: that's how quite you have to be. Subtract that from how loud you are (measure with a sound level meter) and you have the magic number: how much isolation you need. That number will define how to build your walls, ceiling, windows, doors and HVAC system. It's the key to everything. Very important that you get it right.

I am wanting to build the studio in such a way that if we ever do sell the house, it can easily be converted into two normal bedrooms.

That might not be so easy... Highly isolated recording studios and bedrooms don't have a lot in common. The way to get back to "2 bedrooms" would probably to rip out a lot of what you are about to do, then build something more typical of bedrooms. For example, to get the level of isolation you will probably need implies back-to-back doors and room-in-a-room construction: not too many bedrooms are built like that! :)

As you can see in the diagram the control room is 10ft by 10ft

First red flag! And it's a very big flag, very bright red. No two dimensions of your rooms can be the same, nor can they be multiples of each other. The only way to get a worse room than a square, is to build a cube: that's as bad as you can possibly make it. The issue is room modes: if two dimensions are equal, or multiples of each other, then all the modes from both dimensions will line up exactly with each other, so your modal problems will be at least double what they would have been otherwise, and probably even worse than that. You really, really, REALLY need to get away from building your room square.

The control room will be studded out normally, to the basement cement walls,

If your inner leaf studs are attached to your outer leaf, then you do not have good isolation. The two leaves MUST be decoupled, on all sides of the room (including the ceiling).

bass traps will be placed in each corner to to help avoid 90 degree angles.

I'm not sure I understand: How can bass traps "avoid 90° angles"? The only way to avoid 90° angles is to angle the entire wall. A bass trap does not change the angle: it just makes good use of space. And that leads to the next question: why do you want to avoid 90° angles?

There is also a heating duct running from front to back in the control room, which I will be ducting around.

Where is that duct? I don't see it on your diagram, and the position is very important: it is critical that your control room must be perfectly symmetrical, so that duct might be a problem.

If I stud out to the walls and drywall up to the floor joists above, then build a room within that,

Once again, if you attach the inner-leaf studs to the ceiling joists above, or the the existing walls, then you have negated the entire purpose of isolation. The entire inner leaf is a free-standing, decoupled structure. In the very worst case you might need to use isolated sway braces to stabilize it, but ideally you would just build your framing on the slab, and not allow it to touch anything else except the slab.

will I be creating a third leaf?

If you have tow air gaps between the inside of the room and the next room, then you have a third leaf. If you only have one single air gap, then you have two leaves.

1. Just build one room and do staggered studs in the walls to keep sheetrock on both sides from being connected to the same studs,

With staggered studs the drywall is still connected: the sole plate and top plate connect it. Staggered stud is much better than single stud, of course, but not as good as two separate stud frames.

also the walls would be built a coupld of inches away from the outside basement cement walls to create an air gap.

I don't understand why you want to build staggered stud wall a few inches away from another wall: that would create a 3-leaf system. You already HAVE your outer leaf: it is the existing basement walls, floor and ceiling. You do not need to build another outer leaf. You only need to build your inner leaf for each room. So you need to build one stud frame for your control room, consisting of four walls plus a ceiling, and another stud frame for your live room, also consisting of four walls plus a ceiling. Then you put drywall on only ONE side of each of those frames (either the inside or the outside, but not both).

I would then do some type of floating ceiling to try and disconnect the ceiling from the floor joists of my kitchen above. Any ideas on how I can do a floating ceiling properly?

Very simple: you build it on top of the new walls, so that it does not touch the floor above in any way. The new inner-leaf walls support it, not the joists above. Simple place joists across the top of the new walls, with drywall either on top or underneath (not but both). Done!

Then I would do a drop ceiling.I realize that I will lose a couple of inches with the drop ceiling,

Not sure what you mean by "drop ceiling". Are you referring to the typical type of drop ceiling used in many office building these days? Just a simple light-weight metal frame, with polystyrene panels that fit into place? That is no use for a studio: no isolation, and very little acoustic benefit.

blankets on the walls, foam, recommendations?

I assume you are referring to treatment now, not isolation? If so, your best options for treatment (once you have the room suitably isolated), is to build simple panels from wooden frames with 4" OC-703, covered with cloth. Simple, cheap, easy to make, and very effective for room treatment. Blankets and foam are not the best way to go, especially if you want to keep costs down.

Do I need to secure the joints with green glue to get this room tight?

The Green Glue Company makes several different products. Their flag-ship product called simply "Green Glue" is not a sealant, and is not even glue (despite the name). It is a visco-elastic polymer design to be used as constrained layer damping between two layers of drywall. It helps isolation in the low end of the spectrum by damping certain types of internal resonance. The company also makes acoustic sealant, but that's a different product. Yes, you will need to seal everything, an Green Glue Acoustic Sealant is one option. There are others. Order several cases of whatever sealant you decide to use: you will need it!

Should I not leave an air gap in between the cement basement wall and the tracking area exterier wall?

You should DEFINITELY leave an air gap! If you have no air gap, then you have no isolation. An isolation is a tuned filter, basically. It is tuned to a frequency low enough such that it blocks all higher frequencies in the audible range. To tune it low enough, you need a big enough air gap and sufficient mass on the two leaves, plus insulation in the air gap, to act as damping on the various types of internal resonance going on in there.

Would double stud construction not be the best option for the space I have? Once again, I'm trying to keep sound in and out.

Yes. Two separate stud frames is what you need: one for the live room, one for the control room. Right now, you have two walls in your basement that will be part of the isolation system: at the top an left of your diagram. These are your outer leaf. You don't show what is on the right end, but I assume that it is another basement wall? If so, then you have three sides to your outer leaf, in which case you need to build a single stud frame across from left to right, starting where it says "storage" on the left, and ending where it says "machine room" on the right. That frame must connect to the existing basement walls, solidly, and also to the floor above, solidly, and must have drywall on only ONE side of the studs, not both. That completes your outer leaf. Now you build your two single-stud frames within that outer shell: one for the control room, the other for the live room. In both cases, that includes joists across the top of the new stud walls, for the new inner-leaf ceiling. Not put drywall on only ONE side of those frames. That's it! Now you have two complete, fully isolated rooms. Hope that helps, and that I didn't confuse you too much! :) - Stuart -

Soundman2020 wrote:

Acoustic or electric?

I plan to record both. I have looked into it and for my area, the sound should not reach anywhere past the property line which is about 20 feet to the side of our house. The window in the tracking area faces the backyard, where we have no neighbors to the back. The window in the control room, which will not be covered is facing the neighbors to the side/south of us. Any advice on isolation with the proximity to the neighbors I've just described?

Soundman2020 wrote:

The only way to get a worse room than a square

This makes sense to me, however it's what i've got to work with. What could I do to make the square control room the best it can be acoustically? Should I install carpet or laminate in the size of a room? Should I leave the insulation facing the inside of the control room, covered in fabric or would it be best to face the sheetrock side of the wall to the inside?

Soundman2020 wrote:

If your inner leaf studs are attached to your outer leaf, then you do not have good isolation. The two leaves MUST be decoupled, on all sides of the room (including the ceiling).

I will have a room within a room for the control room, but just because of the size of the control room being small as it is, I don't want to lose any space. Also, I'm going to have to stud around the heating vent because as far as I know, that really can't be moved.

Soundman2020 wrote:

I'm not sure I understand: How can bass traps "avoid 90° angles"? The only way to avoid 90° angles is to angle the entire wall. A bass trap does not change the angle: it just makes good use of space. And that leads to the next question: why do you want to avoid 90° angles?

I figured that putting bass traps in the corners would help avoid major reflections. I was under the impression that 90 degree angles are bad for studios because of the reflections they create. Is this not the case?

Soundman2020 wrote:

Where is that duct? I don't see it on your diagram, and the position is very important: it is critical that your control room must be perfectly symmetrical, so that duct might be a problem.

I believe the heating duct is symmetrical enough in the middle of the room to create any major problems. What do you think based on the pictures provided?

Soundman2020 wrote:

I don't understand why you want to build staggered stud wall a few inches away from another wall: that would create a 3-leaf system. You already HAVE your outer leaf: it is the existing basement walls, floor and ceiling. You do not need to build another outer leaf. You only need to build your inner leaf for each room. So you need to build one stud frame for your control room, consisting of four walls plus a ceiling, and another stud frame for your live room, also consisting of four walls plus a ceiling. Then you put drywall on only ONE side of each of those frames (either the inside or the outside, but not both).

I will be building a room within a room design as you have instructed with four inner inner walls and detached ceiling for the tracking area. The 2 by 4s will be set on top of the inner walls. After the air gap between the outer wall and the tracking area, should I attach insulation to the wall on the outside? Because my room isn't big enough to have a "great" acoustic sound, my plan is to put the sheetrock (how thick would you recommend?) on the outside of the stud and face the Roxul Safe n Sound insulation to the inside of the room and cover the walls with fabric. Would you recommend this design in order to kill the sound so I can add reverb later in post production? Also, should I do the the tracking room ceiling the same, with the sheetrock on top of the studs and the Roxul facing down?

Soundman2020 wrote:

Blankets and foam are not the best way to go, especially if you want to keep costs down.

I actually already own blankets that I have around the tracking area of my current studio space. Would I even really need them to kill reflections if I have the Roxul rockwool facing into the tracking area?

Soundman2020 wrote:

To tune it low enough, you need a big enough air gap and sufficient mass on the two leaves, plus insulation in the air gap, to act as damping on the various types of internal resonance going on in there.

How big of an air gap do I need? 3-6 inches? How thick should the sheetrock be?

Soundman2020 wrote:

Right now, you have two walls in your basement that will be part of the isolation system: at the top an left of your diagram. These are your outer leaf. You don't show what is on the right end, but I assume that it is another basement wall? If so, then you have three sides to your outer leaf, in which case you need to build a single stud frame across from left to right, starting where it says "storage" on the left, and ending where it says "machine room" on the right. That frame must connect to the existing basement walls, solidly, and also to the floor above, solidly, and must have drywall on only ONE side of the studs, not both. That completes your outer leaf.

I will be building the 2nd leaf built up to the floor joists above from the left where it says storage to the right where it says machine room like you say. I will then build the tracking room within a room. The current stud wall and the wall I will build up to the floor joists above will be the side and the back walls of the control room. I will then stud out to the walls. I know you mention I will lose isolation if I build the control room this way, but like I mentioned before, I don't want lose much space in the control room. I will then have two doors with glass, for visual with the recording artist. One door in the existing wall to the right of the gray electrical box and one door in the wall of the room within a room tracking area wall. Is using Roxul for all of my insulation, walls, ceilings, etc, going to be overkill or will this best for isolation? What would you recommend to bring the audio snake from the control room to the tracking room. Holes in the walls with PVC pipe running between the to and putty filling the holes around the wires? I know that is part is tricky so as not to lose any isolation. I hope I haven't ranted too much and my questions and responses have made sense. Please let me know what you think of my further explanations and plans. Thanks so much for your help Stuart!

Also, is the HVAC design used in this studio the best way to get heat into the tracking area? What about circulating air? viewtopic.php?f=1&t=15635&start=75

What could I do to make the square control room the best it can be acoustically?

Well, basically, there is no treatment that can fix a square room, except to make it non-square. The issue is simply this: All of the modes associated with the "width" of the room will line up perfectly with all of the modes associated with the "length" of the room, so your modal peaks will be twice as strong, and your modal nulls will be twice as deep. Plus, you will also be left with very large gaps between those modes, where there is no modal support for any tones. So you will have double modes at 56.5 Hz (that's an A on the bass guitar), then at 91.9 Hz. (roughly the fundamental of a kick drum, and also F on the bass guitar) 113 Hz. (A one octave up), 126 Hz., 134 Hz, 145 Hz, and so on, all the way up the scale. Yes, you can try to damp those modes a bit with lots of very large bass traps, but that room is rather small to start with, so the bass traps are going to eat into that space. As long as you are aware of these issues, and can live with them, then that's fine. But if you can change the dimensions even a little, that could make enough difference to improve things considerably.

Should I install carpet or laminate in the size of a room?

Never carpet. Look at photos of professional studios all over the world: How many do you see with fully carpeted floors? Roughly zero.... There's a reason for that: carpet is lousy, acoustically, as it absorbs selectively, and randomly, and unpredictably, and does the exact opposite of what you need. So forget carpet. A plain old concrete floor is great, acoustically, but if you don't like how that looks then you could lay laminate flooring on top of it (with the correct underlay, of course). That's also very good, acoustically.

Should I leave the insulation facing the inside of the control room, covered in fabric or would it be best to face the sheetrock side of the wall to the inside?

Both are options. If you leave the studs facing the room, that is called "inside-out construction" and it does have its uses, especially if you need to save space. Or if you need to change the dimensions of your room... :) For example, you could build the side walls normally, and the front and back walls "inside-out". That would make your room 7 to 14 inches longer than it is wide... :)

but just because of the size of the control room being small as it is, I don't want to lose any space.

There are several techniques that you can use in designing the room to minimize the loss of space. We'll get to those later.

Also, I'm going to have to stud around the heating vent because as far as I know, that really can't be moved.

It will have to be disconnected anyway (you can't go heating up the interior of the wall cavity!), so you might as well call in a plumber to modify the piping to by pass it, and take it out. If you move, you can always put it back in again.

I figured that putting bass traps in the corners would help avoid major reflections.

Bass traps do not stop reflections: they simply absorb acoustic energy, and hopefully only do so for low frequencies. Bass traps might also need minor modifications in order to specifically NOT absorb high frequency energy, and to reflect as much as possible back into the room. You want them to only treat bass, if possible, so they must reflect highs.

I was under the impression that 90 degree angles are bad for studios because of the reflections they create. Is this not the case?

Not really, no. The issue isn't the 90° corners as such, but the parallel walls that they create. Parallel walls provide the possibility for flutter echo to form, which is not nice, but that can be treated with suitable use of absorption. Parallel walls can also send reflections where you don't want them, so walls are often splayed in studios to re-direct the reflections to other places. But you can't do that just by putting insulation in the corner! If you want to get rid of flutter echo and/or re-direct reflections, you can't do that with insulation in the corners: you have to move the entire wall to a different angle. Walls need to be splayed by at least 12° in order to accomplish that.

I believe the heating duct is symmetrical enough in the middle of the room to create any major problems. What do you think based on the pictures provided?

I think that you do not have the room height that you were counting on! Your final finished inner-leaf ceiling will have to go below that heating duct, and that will be the final height of the room. What is the distance between the floor and the bottom of the duct?

The 2 by 4s will be set on top of the inner walls.

Are you sure that 2x4 ceiling joists will be strong enough to span that distance with that load? You should check with a structural engineer or other qualified person to make sure that you are designing that safely. To me, it does not look like it would be safe, but I'm not a structural engineer.

my plan is to put the sheetrock (how thick would you recommend?)

You will need at least one layer of 5/8" drywall, maybe more, depending on how much isolation you need.

on the outside of the stud and face the Roxul Safe n Sound insulation to the inside of the room and cover the walls with fabric.

That's the "inside-out" concept I mentioned earlier. But you probably do not want to do that to the entire room: that would make it sound "dead", which is unpleasant. It should be designed to sound neutral: not too dead and not too live. Both the EBU and ITU have recommendations for that.

I actually already own blankets that I have around the tracking area of my current studio space. Would I even really need them to kill reflections if I have the Roxul rockwool facing into the tracking area?

Probably not, if the room is designed correctly. Blankets are only good for absorbing highs and some mids, but your real problems are going to be in the lows, especially if you have a square room. You are going to need huge amounts of bass trapping, and blankets are no help for that.

How big of an air gap do I need? 3-6 inches? How thick should the sheetrock be?

depends on how much isolation you need, but the absolute minimum recommendation is 4" of air gap and one layer of 5/8" drywall.

I will be building the 2nd leaf built up to the floor joists above

The inner leaf walls cannot touch the existing floor joists! If you do that, you will seriously compromise the isolation, as that would leave direct flanking paths between the leaves. The inner-leaf wall frames must stop short of the existing floor joists above you, and the new inner-leaf ceiling framing must rest only on those new walls. Since you will need structural integrity in sheer, it might be an idea to use 5/8 plywood on the studs, instead of drywall.

The current stud wall and the wall I will build up to the floor joists above will be the side and the back walls of the control room. I will then stud out to the walls.

I'm not sure I follow what you are saying there. It would be much better if you could show that in detail, in SketchUp, so we can see exactly what you ave in mind.

I will then stud out to the walls. I know you mention I will lose isolation if I build the control room this way, but like I mentioned before, I don't want lose much space in the control room.

If your inner leaf is mechanically tied to your outer leaf, then there really isn't much point to building a room-in-a-room at all: you'd be sacrificing practically everything that you gained. You'd be wasting time, money and effort doing that, for very little gain. The entire point of building "room in a room" is to de-couple everything, so that there can be no mechanical transmission of sound. Of you then go and re-couple part of the structure, then you throw away everything you gained. So you probably need to make the decision: do you need isolation, or do you need space? You can't have both, it seems. You cannot bypass the laws of physics, and there are no magical materials that can get more isolation than those laws allow. So the choice you need to make is whether isolation is more important to you, or space. Or you could compromise on both, and find a point where you have reasonable isolation and reasonable space. But in order to do any of that, you'll have to put real numbers to the basic question here: how much isolation do you need? (Measured in decibels). So you need a sound level meter, then measure "how loud you are" at your very loudest, and "how quite you need to be" in order to meet the legal requirements of your area (call your municipality and ask for a copy of the noise regulations). The difference between those two numbers is how much isolation you need, objectively. Based on that you can look at the lists of construction methods that show the level of isolation you can expect from various types of construction, and find one that gives you that level of isolation. If it would make your room too small, then you don't have many options: you either go with a smaller room, or you go with less isolation. There aren0t any other options, unfortunately.

Is using Roxul for all of my insulation, walls, ceilings, etc, going to be overkill or will this best for isolation?

Mineral wool does not isolate. No type of insulation isolates. That isn't the purpose, and it does not work very well. You need many, many FEET of insulation to isolate effectively: Insulation is good for treatment inside a room that has already been isolated, and it is good for damping resonance inside the cavity of isolation walls, which improves isolation, but insulation by itself is pretty lousy at isolating. There are two different concepts here: one is "isolation", which means "stopping sound from getting in or out of the room", and "treatment" which means "making the room sound good". If you isolate a room effectively, then you prevent sound getting out. If it can't get out, then it must stay in! A room full of sound bouncing around all over the place sounds terrible, which is why you need the treatment: to make it sound good again. That's where the insulation comes in: it is really good at mopping up sound that stayed inside.

What would you recommend to bring the audio snake from the control room to the tracking room. Holes in the walls with PVC pipe running between the to and putty filling the holes around the wires? I know that is part is tricky so as not to lose any isolation.

Exactly. that's the best way to get your cables in and out, since it allows you to then repair/replace them easily in the future without tearing down your walls to get at them. But you can't use ordinary PVC pipe: you should use electrical conduit, which is also made from PVC but is not the same as water pipe. There are methods for isolating and decoupling the conduit where it pass through the walls and across the gap between leaves. We'll get to that later.

I hope I haven't ranted too much and my questions and responses have made sense.

No problem! As they say, "The only dumb question is the one you didn't ask!". :) Better to ask lots, explain in detail, and get the picture clear, than to not say anything and make mistakes. - Stuart -

Stuart, Thanks so much for all of your awesome advice. It might take me a bit to process and understand some of your suggestions and come back with more info and questions. It will also take me a bit to learn Sketchup:) in the meantime if you have a good design for my space, I would love to see what kind of layout you might do (if you have time for something like that of course:) Regards-Greg

Hey Stuart, I have redesigned some of the aspects of the studio. I will answer your questions with what I would do different, or keep the same depending on my needs. Please let me know if I am way off on some of my ideas.

Soundman2020 wrote:

Well, basically, there is no treatment that can fix a square room, except to make it non-square.

As noted in the updated, more detailed design (sorry it's not on Sketch-up:) and have made the control room 10 ft. wide by 12.5 feet long. In know that's not changing the dimensions alot, but you said changing it even a little would help:) I have basically taken out the back hallway, lengthened the room, worked the machine room closet back into the utility area and added double doors to keep the sound from the furnace, water heat out of the control room. I have also desided that I need space more than isolation in the control room, so I will be studding out to the outside walls and building around the heating duct above. I think I confused you last time by calling the long heating duct that runs down the center of the control room a heating vent. My fault:) I hope it makes more sense now. I believe I can live and adapt to the control room as described.

Soundman2020 wrote:

Never carpet. Look at photos of professional studios all over the world: How many do you see with fully carpeted floors? Roughly zero.... There's a reason for that: carpet is lousy, acoustically, as it absorbs selectively, and randomly, and unpredictably, and does the exact opposite of what you need. So forget carpet. A plain old concrete floor is great, acoustically, but if you don't like how that looks then you could lay laminate flooring on top of it (with the correct underlay, of course). That's also very good, acoustically.

I will for sure go with laminate flooring for the control room then. What is the correct underlay that you refer to? Also, what kind of flooring would be best for the tracking area, given it's size and all?

Soundman2020 wrote:

Quote: Should I leave the insulation facing the inside of the control room, covered in fabric or would it be best to face the sheetrock side of the wall to the inside? Both are options. If you leave the studs facing the room, that is called "inside-out construction" and it does have its uses, especially if you need to save space. Or if you need to change the dimensions of your room... For example, you could build the side walls normally, and the front and back walls "inside-out". That would make your room 7 to 14 inches longer than it is wide...

I believe I will go with the inside-out construction approach just to help deadin the room. In the second part of this last quote from you, you said to build the side walls normally and the front and back walls inside-out. I'm not really sure what you mean by this. Does that mean to build two of the walls with the insulation facing in and two with the sheetrock facing in? Also, it seems like it would be best to face the sheetrock down in the tracking area ceiling, rather than the roxul covered in fabric down. Is this the best option. I'm thinking that putting the sheetrock facing down for the ceiling will add a little bit to a very dead sounding room. Is this a good idea?

Soundman2020 wrote:

Bass traps do not stop reflections: they simply absorb acoustic energy, and hopefully only do so for low frequencies. Bass traps might also need minor modifications in order to specifically NOT absorb high frequency energy, and to reflect as much as possible back into the room. You want them to only treat bass, if possible, so they must reflect highs.

Gotcha:)

Soundman2020 wrote:

The issue isn't the 90° corners as such, but the parallel walls that they create.

Thanks for clearing this minconception up. I will just have to do what I can with absorption to compensate for the parallel wall issues.

Soundman2020 wrote:

Are you sure that 2x4 ceiling joists will be strong enough to span that distance with that load?

I will check on this. The last thing I want is for the ceiling to colapse on a singer during a perfect take :wink:

Soundman2020 wrote:

That's the "inside-out" concept I mentioned earlier. But you probably do not want to do that to the entire room: that would make it sound "dead", which is unpleasant. It should be designed to sound neutral: not too dead and not too live. Both the EBU and ITU have recommendations for that.

I'm guessing that my updated design will sound too dead then? What would you recommend to livin it up enough?

Soundman2020 wrote:

The inner leaf walls cannot touch the existing floor joists! If you do that, you will seriously compromise the isolation, as that would leave direct flanking paths between the leaves. The inner-leaf wall frames must stop short of the existing floor joists above you, and the new inner-leaf ceiling framing must rest only on those new walls. Since you will need structural integrity in sheer, it might be an idea to use 5/8 plywood on the studs, instead of drywall.

The tracking area will be built with the room-within-a room design and will not be touching the the joists above. I also made the wall that runs along the bathroom and storage act as the 2nd leaf in my new design. Is this a bad idea or will it work? You mention using 5/8 plywood for the room-within-a-room. Does this mean on the outside walls and ceiling of the room and note use sheetrock at all?

Soundman2020 wrote:

The current stud wall and the wall I will build up to the floor joists above will be the side and the back walls of the control room. I will then stud out to the walls.

Here I am referring to building the control room out to the walls and up to the floor joists above, using the existing studded wall as the fourth wall of the room. As I mentioned before, this is worth it to me to gain more space and less isolation in the control room.

Soundman2020 wrote:

Mineral wool does not isolate. No type of insulation isolates. That isn't the purpose, and it does not work very well. You need many, many FEET of insulation to isolate effectively: Insulation is good for treatment inside a room that has already been isolated, and it is good for damping resonance inside the cavity of isolation walls, which improves isolation, but insulation by itself is pretty lousy at isolating.

So I'm isolating the room by putting a 4 inch air/insulation GAP between the tracking area outer wall and the contrete outer walls, right? And the layer of Roxul facing the inside of the room is the treatment, right? I realize that with the control room I am sacrificing isolation for space. I really just needed the tracking area decoupled and isolated because it will be getting the loudest in there, and that's the area I'm trying the hardest to keep sound out of for obvious reasons. About the tube that will connect the snacks. How do I make that so it doesn't connect the two rooms with a solid material. I know it's not much of a connection, but I know it's all pretty critical. Do I put two seperate pieces of pipe in the walls and let the snake wire be exposed inside the air gap. Also, what is the best option for lighting in the tracking area? Will pulling lighting wires from above be making too hard of a connection from above? Maybe floor lamps would be best here...I don't know. Please let me know if I am heading in the right direction of if I'm lost at sea. Thanks so much for your help Stuart! I really do appreciate it a ton:) -Greg

have made the control room 10 ft. wide by 12.5 feet long. In know that's not changing the dimensions alot, but you said changing it even a little would help:)

That should be enough.

I will for sure go with laminate flooring for the control room then. What is the correct underlay that you refer to?

Depends on the manufacturer: go with whatever they recommend. Normally it is some type of thin foam, sometimes metalized or with foil on one side.

Also, what kind of flooring would be best for the tracking area, given it's size and all?

Laminate would work fine for that too.

I'm not really sure what you mean by this. Does that mean to build two of the walls with the insulation facing in and two with the sheetrock facing in?

Yep, that's the idea.

Also, it seems like it would be best to face the sheetrock down in the tracking area ceiling, rather than the roxul covered in fabric down. Is this the best option. I'm thinking that putting the sheetrock facing down for the ceiling will add a little bit to a very dead sounding room. Is this a good idea?

Actually, it is the other way around: Sheetrock is quite reflective, so it is better to do the ceiling with the sheetrock facing up, and the roxul facing down. The general rule is "hard floor - soft ceiling".

I'm guessing that my updated design will sound too dead then? What would you recommend to livin it up enough?

You can cover some of the insulation with plastic (6 mil polyethylene works well), or even very thin plywood in places, to reflect back some of the highs while still allowing the lows to get through.

The tracking area will be built with the room-within-a room design and will not be touching the the joists above. I also made the wall that runs along the bathroom and storage act as the 2nd leaf in my new design.

As long as the two sides of the wall are decoupled (no hard mechanical connection), then that's fine.

So I'm isolating the room by putting a 4 inch air/insulation GAP between the tracking area outer wall and the contrete outer walls, right?

Yep! That 4 inches is the distance across the gap, between the face of the concrete and the face of the sheetrock.

And the layer of Roxul facing the inside of the room is the treatment, right?

You still need insulation inside the wall, between the concrete and the sheetrock. That is important for maximum isolation.

I know it's not much of a connection, but I know it's all pretty critical. Do I put two seperate pieces of pipe in the walls and let the snake wire be exposed inside the air gap.

Use conduit, cut a small section out of the conduit, and wrap that with thick rubber such as EPDM or Neoprene. Like this:

Your help has been great Stuart. I am learning a ton about studio design. Here are some additional clarification questions before I start purchasing materials and building.

Soundman2020 wrote:

Quote: I'm not really sure what you mean by this. Does that mean to build two of the walls with the insulation facing in and two with the sheetrock facing in? Yep, that's the idea.

I'm thinking I will make the walls who's corners touch with the insulation facing in and the other two walls with the sheetrock (or plywood) facing in. In other words, I won't have the same material walls running parallel to each other. I figure this will help to avoid reflections from parallel walls. Is this the right idea? Which two walls would you make with the insulation facing in and which two would you make with the hard material facing in? Also what kind of fabric would you use to cover the Roxul on the walls where the Roxul is facing in? What about lighting for the tracking room? Should I just use floor lamps because the ceiling will be soft with the Roxul and fabric facing down? How about doors. What is the best material to make the doors out of, including the 2 parallel doors between the control room and tracking area? Should I be using Roxul throughout the entire studio/bathroom and storage, including overhead beween the floor joists, or are there any places it would be overkill and I could use a less expensive fiberglass insulation? Either way is ok, I just want to be pushing my money as far as I can on this project. I believe that these are my final questions before I begin construction. Are there any other important items I am overlooking? Thanks Stuart! Regards-Greg

Stuart, two things I forgot... Is the HVAC box that I have seen with the different seperaters and full of insulation the best option for getting air into the studio? What is the best way to ceil off the top left window next to the tracking area, both waterproof wise and soundproof wise? Thanks again for all your help.

Bump:)

Is the HVAC box that I have seen with the different seperaters and full of insulation the best option for getting air into the studio?

Yep! You still need a fan, of course, and ducting, but those silencer boxes (a.k.a "baffle boxes") are the way to go. You need two sets: one to bring fresh air into the room, the other to exhaust stale air.

What is the best way to ceil off the top left window next to the tracking area, both waterproof wise and soundproof wise?

Best way? Brick it up! :) Second best: build a window "plug" that fits into the opening. There are examples on the forum, which you can probably find using the "search" feature. I say "probably" because that search thing isn't very useful... :) - Stuart -

Thanks for the response:) any final advice on the questions I posted right before my last one? About insulation, lighting, etc.? Man I am full of questions:) thanks for your patience! -Greg

Man I am full of questions:)

That's what this place is for! :)

Thanks for the response:) any final advice on the questions I posted right before my last one? About insulation, lighting, etc.?

OK...

I figure this will help to avoid reflections from parallel walls. Is this the right idea? Which two walls would you make with the insulation facing in and which two would you make with the hard material facing in?

That is, indeed, the right idea. It doesn't really matter which two walls you choose, since we are talking about a live room here.

Also what kind of fabric would you use to cover the Roxul on the walls where the Roxul is facing in?

Any type, as long as it is "breathable". In other words, if you hold a piece over your mouth and nose you should be able to breathe through it easily, with little noticeable resistance.

What about lighting for the tracking room? Should I just use floor lamps because the ceiling will be soft with the Roxul and fabric facing down?

Floor lamps is one option, or you could embed lights in the framing of your ceiling and/or ceiling cloud. Look around the forum at some of the threads of finished studios to get ideas on how to do that.

How about doors. What is the best material to make the doors out of, including the 2 parallel doors between the control room and tracking area?

Doors must be massive (heavy) in order to isolate. A common method here is to purchase ordinary solid-core doors (never hollow core, never foam core), and add more mass to them with additional layers of MDF. Once again, there are many build threads on the forum where people have done just that, so you can see hoe they did it.

Should I be using Roxul throughout the entire studio/bathroom and storage, including overhead beween the floor joists, or are there any places it would be overkill and I could use a less expensive fiberglass insulation? Either way is ok, I just want to be pushing my money as far as I can on this project.

You can use either fiberglass or mineral wool, whichever is less expensive. If you use fiberglass then the density should be about 30 kg/m3, and if you use mineral wool then the density should be about 50 kg/m3. Those are the optimal figures for isolation, but there is a fairly wide margin there. - Stuart -

"You can use either fiberglass or mineral wool, whichever is less expensive. If you use fiberglass then the density should be about 30 kg/m3, and if you use mineral wool then the density should be about 50 kg/m3. Those are the optimal figures for isolation, but there is a fairly wide margin there. -Stuart" I just want to clarify what you mean by this. Are you saying to use whichever is cheaper throughout the whole studio or just in the less important parts as far as isolation is concerned. I guess I was under he impression that mineral wool is a ton better for studio builds. If I could use 30kg fiberglass throughout be whole thing that would sure help me spread my money further, you know what I mean. I just want to clarify this before I order my insulation...:) thanks! -Greg

What matters is neither the density nor the cost. What matters, from the acoustical point of view, is gas flow resistivity. That's the characteristic of the isolation that defines how well it acts on sound waves "flowing" though it. There's an optimal range for that for different applications. The problem is that many manufacturers of insulation do not bother measuring or publishing their gas flow resistivity figures: Fortunately, it turns out that for each class of material there is rough relationship between gas flow resistivity and density. Greater density usually means high resistivity, which means the product will probably perform better at high frequencies, and not so well at low frequencies. Lower densities means the reverse. Sort of. The relationship isn't totally linear, but is sufficiently good to make it possible to provide general rules of thumb, such as the above two about fiberglass and mineral wool. Of course, it isn't just that simple: nothing is in acoustics! This is actually a measure of impedance, so the effect varies for different frequencies. That's why manufacturers publish tables and graphs showing the absorption coefficients at various points across the spectrum. So some products are better than others for certain applications, while being worse for other applications. That said, if we are just talking about damping resonance inside the cavity of an MSM wall, then it doesn't really matter if you choose fiberglass or mineral wool, as they both act more or less the same in that application. So go ahead and damp your cavity with whatever turns out to be less expensive in your area, provided that it is roughly in the ranges I gave above. This "rule of thumb" works because the resonance that you are dealing with in wall cavities fall within the optimum range for the densities we are talking about. If you were building a deep bass trap then you'd probably want to go with a lower density product, whereas if you were more interested in dealing with high frequencies without affect the lows so much, then you'd probably want a very high density type of insulation. But for wall cavities in home studios, there really isn't much to choose between 30 kg/m3 fiberglass and 50 kg/m3 mineral wool. - Stuart -

Hey Stuart, I have started my studio build. I think I will be using the pink R-30 insulation in my room within a room walls and ceiling instead of mineral wool. Is this the same as 30kg/m3? Also will not having any dense insulation in the entire basement studio hurt high frequencies? Instead of the two doors between the control room and tracking area there will be two panes of insulated glass. What thicknesses should they be to be affective? There will be a 4-6 air gap between the two panes...thanks! Greg

I think I will be using the pink R-30 insulation in my room within a room walls and ceiling instead of mineral wool. Is this the same as 30kg/m3?

No- R ratings are to do with thermal insulation, and are not very much related to density. Where you live, density is probably given in pounds per cubic foot (PCF, or lb/ft2), rather than kilograms per cubic meter, so look for fiberglass with a density or around 2 PCF. That's what you need.

Also will not having any dense insulation in the entire basement studio hurt high frequencies?

Not really. The lighter stuff is still darn good at absorbing highs, and in fact too much so! You will very likely need to cover the front of your bass traps with plastic, or even thin plywood, to keep them from sucking out too much of the highs!

Instead of the two doors between the control room and tracking area there will be two panes of insulated glass

You need laminated glass, not insulated glass.

What thicknesses should they be to be affective?

The idea is to keep the surface density constant across the entire wall, so you need the thickness of glass that will accomplish that. Glass is ery roughly three times more dense than drywall, so you need glass that is about one third the TOTAL thickness of your drywall. So if you have two layers of 5/8" drywall on each leaf, then you'd need glass that is around 7/16".

There will be a 4-6 air gap between the two panes

If that's the same size as the air gap between your leaves, then that's fine. But if there is less air gap between the glass then you'll need thicker glass. - Stuart -

Hello Stuart, I am currently sanding the control room walls and am about to get ready to start the tracking room (I will get a studio build thread start soon. I have 2 different ideas on how to build the room within a room ceiling. The reason I think idea #2 would be good is because it would take less wait off of the room within a room ceiling/walls because the 2nd layer of drywall would be attached to the flooring above. My question is if I would be creating a third leaf in idea #2. Which idea would be best at keeping sound out and in. Idea #1 seems like it would decouple both pieces of drywall/mass, creating a better seal, even though it would be heavier on the ceiling and walls. Anyways, thanks for all your help. Regards-Greg

My question is if I would be creating a third leaf in idea #2.

Yes, that would be creating a 3-leaf system.

Idea #1 seems like it would decouple both pieces of drywall/mass

Correct! :) - Stuart -