John Sayers' Recording Studio Design Forum Archive

John or Steve,

I've been reading through lots of threads on various subjects and think that I have a fair understanding of issues I am trying to work around.

That being said, I am scared of messing up my rooms, so if I may, I'd like to ask a few specific questions referencing some areas on my plan.

Before I begin, I'll give some explanation into the space being worked with:

1) It is in a residential basement with neighbors within 20 feet of the right most wall
2) The ceiling height is 8 feet to the bottom the I-beam
3) All 4 walls are concrete foundation, with the only opening to the rest of the basement space being the doorway on the bottom left of the plan
4) The outer perimeter walls are already framed, insulated and vapor barriered as per code in the my area from when the house was built
5) The floor is poured cement
6) The walls are approx 80% below grade on three sides with the garage foundation and flooring being on the 4th side (the bottom of the pla)

Here are the questions I am wrestling with in order to start framing with a contractor on March 6th.

1) (Referencing DRAWING A - POINT A) As mentioned, the wall along the perimeter is already framed and insulated. I was thinking I was going to drywall this wall behind the soffit area and then build the soffit wall once the room was sealed up. That being said, it is now my understanding that this would create a 3rd leaf and would actually lower the isolation of the room. However, I am planning on building the soffits exactly as per John's plans (DRAWING B) minus the air hole at the top of the wall and the air space behind the speaker (my speakers are passive, so I don't see a need for this... just simple sealed boxes with a hole for the wire to exit), which has opening for the bass trap and airflow, so I'm not sure if this would still be considered a 3rd leaf. I am also concerned that not sealing up the wall behind the soffits would violate the building code in our area etc.
QUESTIONS:
1a) Should the wall behind the soffits be drywalled and sealed up?
1b) Does the difference in cavity size for the left and right soffit have any effect on their sound/will it make the room imbalanced?
1c) Given the size of the room, do you forsee modal problem?
1d) Given the size of the room, I am planning on a dead back wall and a slat wall between the speaker soffits. Is that the best use of the space?
1e) I was not planning on angling the soffits down. Given an 8 foot ceiling, is there a recommended distance from the floor and or ceiling that the speakers (Event 20/20s) should be placed?


2) (Referencing DRAWING A - POINT B) The air cavity in this space forms a triangle with three walls.
QUESTIONS:
2a) Does this cause me issues from a leaf perspective? IE - do the walls to the control room and the upper right live room act as part of a 2 leaf system, or will the third wall (foundation wall at the top between them) cause it to act as a 3 leaf system? I do plan on cutting the outer framing inside of the air space to decouple the rooms, but I cannot obviously remove the concrete foundation.

3) (Referencing DRAWING A - POINT C) This door way will be constructed of two solid-core doors with proper sealing etc.
QUESTIONS:
3a) The upper live room is meant for drums. Does it make more sense to place the door where the window below it is located (entering into the lower live room instead) in order to maximize the isolation of the upper live room? The top one is meant for drums and the bottom one is meant for vocals and amps.

4) (Referencing DRAWING A - POINT D) This room is the room intended for use as a drum room
QUESTIONS:
4a) The room dimensions equate to 9 feet at the top in width, tapering down to 6 feet 10 inches at the bottom and a length of 8 feet. Ceiling height is 8 feet. Will this room (albeit small) work for drums or am I wasting my time? I would be putting in pergo flooring with a rug for the drums/possibly an isolated riser for the drums and then treating the ceiling with multiple bass trap hanging pointing down directly at the kit
4b) The air space at the top of the plan between the drum room and control room is 2 feet 8 inches. Could that be lessened down to 1 foot or so to gain another 1 foot 8 inches in the drum room?

5) General information regarding the build.
QUESTIONS:
5a) I was planning fastening the walls to the concrete using Tapcons (since I am not floating the floor). The rooms do not share walls (with the exception of the wall between the two live rooms). Are Tapcons ok to use in this situation or will that ruin me right from the start?
5b) The outer perimeter (already framed) goes completely from floor to ceiling where it touches the I-beams. The I-beams go from the top of the plan to the bottom, so they luckily do not traverse from room to room, but they will couple the walls to the floor above it. I am planning on using multiple layers of drywall on resilient channel for ALL walls and ceilings. Should I be able to leave the existing walls even if the touch the I-beams?
5c) Is it recommended to nail AND glue all framing, or is nailing sufficient?

Thanks for any help... I'm feeling very overwhelmed at the moment.

Jim

Steve,

Any comments to make? I've got framers coming in on Monday and I want to make sure I know what I'm doing

Thanks,
Jim

Jim, it's kinda the wrong time of my work cycle for anything more than a "yup" or "nope", but will get completely caught up sometime this weekend. PM me as a reminder, and I'll put you near the head of the list(right after Len, who's been more patient than Job ) - Hope that works for you... Steve

Steve,

More than fair... and I appreciate it.

I just wanted to make sure I hadn't done something wrong (causing me to fall off the list)

Thanks for your kindness and I look forward to your comments over the weekend.

Jim

Jim, trust me; if ANYONE "falls off my list", they won't have to ASK...

Jim; first off, this weekend went NOTHING as I'd hoped; I ended up having to cover last-minute absence, so worked two extra 12-hour shifts (yuchhhh...) so got NOTHING done on anyone's stuff. Second, the nature of this (free) resource is that I'm left "holding the bag" on Barefoot's previous forums as well as the Construction one, so I get spread even thinner - so a list of questions this long should normally allow more response time especially when bringing in outside help on a schedule.

That said, since you are at this point probably looking at paid help standing around, I've decided to move you to the top of the list (Len, if you're reading this PM me - I have a suggestion you will probably like)

OK, on to the meat -

1) (Referencing DRAWING A - POINT A) As mentioned, the wall along the perimeter is already framed and insulated. I was thinking I was going to drywall this wall behind the soffit area and then build the soffit wall once the room was sealed up. That being said, it is now my understanding that this would create a 3rd leaf and would actually lower the isolation of the room. However, I am planning on building the soffits exactly as per John's plans (DRAWING B) minus the air hole at the top of the wall and the air space behind the speaker (my speakers are passive, so I don't see a need for this... just simple sealed boxes with a hole for the wire to exit), which has opening for the bass trap and airflow, so I'm not sure if this would still be considered a 3rd leaf. I am also concerned that not sealing up the wall behind the soffits would violate the building code in our area etc.

QUESTIONS:
1a) Should the wall behind the soffits be drywalled and sealed up?

Yes; can't be helped. The solid parts of the soffit wall will act somewhat as a third leaf, but the vents will keep you from using that structure as your inner leaf. Since this is the CR, volume levels shoud rarely exceed 90 dB so your concrete should handle that even WITH the partial 3-leaf sections.

1b) Does the difference in cavity size for the left and right soffit have any effect on their sound/will it make the room imbalanced?

Shouldn't be noticeable at all - any porting/filling with insulation of the space will only enhance base trapping, which affects the entire room and at freuencies that are OMNIdirectional.

1c) Given the size of the room, do you forsee modal problem?

NO. Bonello distribution (I averaged side walls, guessed at approx. 12 feet, so used dim's of 14,12,8) looks good, and the splayed walls will alleviate the 2:3 ratio of your width/ceiling (average) dim's.

1d) Given the size of the room, I am planning on a dead back wall and a slat wall between the speaker soffits. Is that the best use of the space?

Yes. If using slats between speakers, get a laser pointer and a friend, hold the laser at the speaker and aim it toward any and all hard surfaces - where it shines on a surface, hold a mirror there and find the NEXT point of reflection -do this until the total path length is at least 20 FEET longer than the DIRECT path to your mix position, and absorb any section that will allow this path to NOT be absorbed (except for the slats between speakers, that is - any reflection paths that are too short should be absorbed on the SECOND reflection points -

Be sure and aim the laser to BOTH sides of BOTH speakers so you don't miss any early reflection points - even splayed walls need this, unless they are splayed so much that there are NO points along their surface that will reflect directly to the mix position, or unless the room is so large that ALL early reflection paths are more than 20 feet longer than the direct paths.

1e) I was not planning on angling the soffits down. Given an 8 foot ceiling, is there a recommended distance from the floor and or ceiling that the speakers (Event 20/20s) should be placed?

Yes. NOT centered vertically, EVER - that said, placed at ear height when sitting, but this isn't often practical either. 38% or 62% of total ceiling height, whichever is closer to your ear height works modally, but places speakers in an 8' tall room either at 3.5 feet or at 4.5 feet (woofer center) - the lower one makes it likely you'll get reflections off the rear of your mix table (so that surface needs absorbed) and it means that any auxiliary nearfields will likely be in the way of the mains, so you'd need to move them out of the way when using mains, or at least wrap them in 703 to kill reflections/diffractions of the sound field coming from the mains.

If you've downloaded the Harmon mode calculator

http://www.harman.com/wp/index.jsp?articleId=131

plug in your ceiling height and stay AWAY from any heights (ears OR speakers) where ANY modes are at MINIMUM level - try for an average somewhere between peak and null, and place center of woofers and ears at that height.

If that puts your ears at too much different height than the tweets, I would seriously consider tilting your soffits to make up for it.

2) (Referencing DRAWING A - POINT B) The air cavity in this space forms a triangle with three walls.

QUESTIONS:
2a) Does this cause me issues from a leaf perspective? IE - do the walls to the control room and the upper right live room act as part of a 2 leaf system, or will the third wall (foundation wall at the top between them) cause it to act as a 3 leaf system? I do plan on cutting the outer framing inside of the air space to decouple the rooms, but I cannot obviously remove the concrete foundation.

The concrete will flank between the rooms, so your inner framing DOES need to be separated room-to-room to combat this. Otherwise you'll get a noticeable loss of isolation between rooms. Also, I'd build your wall between CR and LR WITHOUT the splay - IOW, the wall frames can be parallel to each other. Weakest link theory at work here; your iso will only be as good as the NARROWEST air gap allows, so why waste the space that could be used as a larger live room. Don't hard-couple frames other than at the floor, and use some sort of breathable surround that will allow the air space between doors to VENT into the insulation between walls. This will improve TL of the doors a couple dB.

Ceilings should ALSO be separate, for the INNER leaf - same reason; one continuous leaf on ceilings will also FLANK between rooms.

3) (Referencing DRAWING A - POINT C) This door way will be constructed of two solid-core doors with proper sealing etc.

QUESTIONS:
3a) The upper live room is meant for drums. Does it make more sense to place the door where the window below it is located (entering into the lower live room instead) in order to maximize the isolation of the upper live room? The top one is meant for drums and the bottom one is meant for vocals and amps.

Yes. No matter how good your door seals, NO DOOR is better. Glass thickness needs to be AT LEAST 1/3 the thickness of TOTAL drywall thickness in EACH LEAF.

4) (Referencing DRAWING A - POINT D) This room is the room intended for use as a drum room

QUESTIONS:
4a) The room dimensions equate to 9 feet at the top in width, tapering down to 6 feet 10 inches at the bottom and a length of 8 feet. Ceiling height is 8 feet. Will this room (albeit small) work for drums or am I wasting my time? I would be putting in pergo flooring with a rug for the drums/possibly an isolated riser for the drums and then treating the ceiling with multiple bass trap hanging pointing down directly at the kit

Your dim's will change if you parallel the walls between CR and drum room, so I'd add a slat resonator across part of that corner (next to the CR, above the window) tuned to center of 300 hZ (kick drum first mode) - beyond that, it's better to "tune to taste" AFTER building -

4b) The air space at the top of the plan between the drum room and control room is 2 feet 8 inches. Could that be lessened down to 1 foot or so to gain another 1 foot 8 inches in the drum room?

See earlier comments.

5) General information regarding the build.

QUESTIONS:
5a) I was planning fastening the walls to the concrete using Tapcons (since I am not floating the floor). The rooms do not share walls (with the exception of the wall between the two live rooms). Are Tapcons ok to use in this situation or will that ruin me right from the start?

You do NOT want hard fastening between inner frame and concrete, see my comments above on FLANKING. Leave at least an inch air space between the closest part of your inner wall frame and the concrete, and brace the walls with isolators such as RISC-04's, as I explained/drew in TomM's thread

http://www.johnlsayers.com/phpBB2/viewt ... 9&start=60

5b) The outer perimeter (already framed) goes completely from floor to ceiling where it touches the I-beams. The I-beams go from the top of the plan to the bottom, so they luckily do not traverse from room to room, but they will couple the walls to the floor above it. I am planning on using multiple layers of drywall on resilient channel for ALL walls and ceilings. Should I be able to leave the existing walls even if the touch the I-beams?

Don't think so; this sounds like an efficient FLANKING path. Anywhere you can't use separate frames (no hard contact with outer walls or structure, other than the floor) you should use resilient mounts. If you're planning on more than 2 layers of wallboard, I'd go with RSIC's instead of RC for the extra strength (and a couple dB better iso at midrange)

5c) Is it recommended to nail AND glue all framing, or is nailing sufficient?

Nailing is fine; but if your guys aren't studio builders and they ARE using nail guns, make sure they know that TIGHT construction is necessary. Hammers pull framing together, but nail guns are so fast that they drive the nail without moving the boards, so a strong grip holding the studs against each other while nailing will be necessary.

Thanks for any help... I'm feeling very overwhelmed at the moment.

Join the club... HTH... Steve

Steve,

No problem... thanks for getting back to me!

I know all to well how it is when things don't go according to plan (work related!)

I may have already made some mistakes according to your notes that I need to check with you on.

When I was referring to Tapcons, I was referring to anchoring the inner walls to the floor, not to the outer walls, which is what I did.

I did in fact lessen that splay on the CR wall, I actually opened to control room angle by 1 foot 8 inches, so the gap now is only 1 ft at the widest and 2 inches between every other inner wall.

I will cut the sill plate of the outer 2x4 walls between rooms.

Questions:

1) When the contractors built the walls, the built them with the studs parallel to each other... not offset. Is that a huge problem? IE - there is one wall and then another SEPARATE wall 2 inches away, but the stud pattern is the same. I am planning on resilient channel on BOTH walls if that makes any difference.

2) "Ceilings should ALSO be separate, for the INNER leaf - same reason; one continuous leaf on ceilings will also FLANK between rooms." I was planning on tying the inner wall studs to the I-beams above them and then hanging all interior walls (including ceiling) from resilient channel. I understand that not using pucks or something to isolate the wall from the Ibeam causes me some flanking issues, but will it be huge with the ceiling still on a resilient channel?

Basically what I am asking is that if the FRAMING winds up having some hard contact (with the I-beams or because of the pre-existing frames along the outer walls), will using the resilient channels and hanging ALL drywall (walls and ceiling) in ALL rooms combat that?

3) You mentioned some acoustic treatment to do if I put slats between the CR speakers... if I just make the front wall dead as well (as the back wall) is that a better use of the space? IE - bass traps under the CR speakers and high/mid trapping in the middle?

Thanks again for the help.

The area already looks sweet, I just hope I don't screw it up!!!

Jim

When I was referring to Tapcons, I was referring to anchoring the inner walls to the floor, not to the outer walls, which is what I did.

That's fine, you're not floating your floor; and RC (or RSIC's) on all surfaces like you're talking about, while not necessary in some of your instances, will make sure you have no hard contact between any INNER masses and your structure going up into the rest of the house.

I did in fact lessen that splay on the CR wall, I actually opened to control room angle by 1 foot 8 inches, so the gap now is only 1 ft at the widest and 2 inches between every other inner wall.

You don't mean that you changed ONE side of the CR and not the other, do you?

I will cut the sill plate of the outer 2x4 walls between rooms.

And the TOP plate as well...

Questions:

1) When the contractors built the walls, the built them with the studs parallel to each other... not offset. Is that a huge problem? IE - there is one wall and then another SEPARATE wall 2 inches away, but the stud pattern is the same. I am planning on resilient channel on BOTH walls if that makes any difference.

No problem. I'm not even aware of any tests showing the comparison of "coincidently" framed double walls vs. "offset" framed double walls - it's my thought that there may be a slight advantage to offsetting, because it seems like wherever a section of wallboard wants to vibrate, there would be a stiffener on the opposing side to lessen the amount transferred to the opposing mass - so far, just theory. I wouldn't worry about it - for one thing, while working inside it's nice to be able to just "walk thru the wall" (at least til the drywall's up) and that's not easy with staggered studs...

2) "Ceilings should ALSO be separate, for the INNER leaf - same reason; one continuous leaf on ceilings will also FLANK between rooms." I was planning on tying the inner wall studs to the I-beams above them and then hanging all interior walls (including ceiling) from resilient channel. I understand that not using pucks or something to isolate the wall from the Ibeam causes me some flanking issues, but will it be huge with the ceiling still on a resilient channel?

Basically what I am asking is that if the FRAMING winds up having some hard contact (with the I-beams or because of the pre-existing frames along the outer walls), will using the resilient channels and hanging ALL drywall (walls and ceiling) in ALL rooms combat that?


Yes, that will work. If you intend using more than 2 layers of drywall tho, I'd go with RSIC's and hat channel instead of RC. And make sure you mark each and every stud's location in masking tape on adjacent surfaces before you drywall, so you don't "short out" the RC by running a screw thru it and into the frame. Also, you'll need "steel" type drywall screws for the RC (fine thread) and two different lengths, one for each layer.

3) You mentioned some acoustic treatment to do if I put slats between the CR speakers... if I just make the front wall dead as well (as the back wall) is that a better use of the space? IE - bass traps under the CR speakers and high/mid trapping in the middle?

Depends on your intent; if you'll be doing surround work, you'll want ALL surfaces more or less dead in the room. If only stereo, then live front is fine. Surround speakers will give early reflection problems off front reflective walls. Check out this

http://www.grammy.com/PDFs/Recording_Ac ... _1_Rec.pdf

for more.

General rule - if any part of the framing for a wall or ceiling will be in hard contact with the rest of the building's structure, then resilient mounting of drywall ON THAT FRAME is necessary. If not, then separate frames do NOT need additional isolation by resilient mounts.

2nd General rule - you do NOT want continuous ceilings between isolated rooms, nor would this do anything but HURT your isolation to the upstairs - think about it: wallboard = mass one, air between walls = air #1, inner ceiling wallboard = mass2, air behind that = air #2, upstairs floor = mass 3. Not good. If you subtract that inner ceiling wallboard, you're back to mass-air-mass between EITHER room and the upstairs. Voila.... Steve

Steve,

Thanks again!!

By continuous ceiling, you mean drywall covering the entire ceiling of all rooms right? I don't have that. Each room will have its own ceiling, but each ceiling will be hanging from shared I-beams... meaning the ceiling's channels (resilient) will be connected to the existing I-beams, but EACH room will have its own ceiling - IE - the drywall of the CR ceiling will not physically touch the drywall of the LR ceiling.

As for the control room wall... I only move one wall, at one end by basically 1.5 feet (the front INNER control room wall). I did not change the mid-point.

I suppose that screws up my modal characteristics of the room!?!

Thanks again... I'm feeling more and more confident (seriously) that I will have workable space!

Jim

So you moved the CR side of that wall further toward the drum room? I'd have thought you'd go the OTHER way, for more "air" in the drum room and NOT changing your angles in the CR.

Will you balance out the soffits, etc, so it's still plane symmetrical? (Please say yes...) Steve

Just looked over your nearly identical post in Speakers, and if that right side wall is to neighbors I would NOT put any finish (or texture) on your drywall til you TEST - you may well wanna go 3 layers EVERYWHERE in the drum room before you're done... Steve

Steve,

Yes... I move the one corner of the CR out 1.5 ft and I will be balancing out the soffits etc... the room will still be symmetrical.

Did moving my wall by 1 ft cause me modal issues now? I sure hope not.

I don't believe the angles in the CR were done to scientific specs... it was more the architects rendition of what John Sayers had drawn out for me.

My reasoning for moving the control room out is actually that I will be using it the most, therefore wanted the additional space. The drum room is a "once in a while" type room.

I also have a home theater (also being isolated with the same construction) on the other side of the studio entrance, and figured I can set up large kits in there if I have to.

Yes, I had posted a while back in the speaker forum too and realized that I probably hadn't asked complete enough questions or posted enough detail... which is why I started a new thread. Wasn't trying to cross post, just was trying to be as thorough explaining as could be.

Great idea in the drum room. I very well might want to go three layers there. Would you think three layers in that room alone would suffice for muffling out the drums a little more? I plan on having guitar amps in the smaller room as well as vocals.

Thanks,
Jim

CR angles should be fine; until you reach a point where you're splaying the side walls (and ceiling) enough to create a RFZ with no absorption necessary, the only important thing is to splay them 6 degrees or more per side (1 foot in 10) - this handles flutter so then you only need absorption at first reflection points, and then enough to deaden the room to taste (usually notably "drier" than live rooms, so you're not fooled into thinking you have enough reverb in the mix.

If you follow my two "general rules" when deciding whether to use RC, you should be fine - and your ceilings are happening the RIGHT way too... Steve

Steve,

Awesome. Thanks so much.

I will post pics tonight or tomorrow once the framing is done.

Jim

Steve,

Ok... framing is pretty much done (carpenters are coming back for a 3RD DAY!! and I had to order another 50 8 foot 2x4s... yikes)...

I do have one question though that has me a little concerned.

In the vocal booth (the room to the lower right), they lowered the whole ceiling to get around existing HVAC and water pipes. This is great for sound proofind, as it give me more air space between the floor above me, but it lowers my ceiling height considerable.

The room's measurements are as follows:

(see attached drawing)

The measurements I am giving are framed, but not drywalled.

The ceiling height (again - framed, but not drywalled) is 7'

Seems like I have VERY similar measurements on all sides with two points being ~6 ft and two points + ceiling height being at ~7 ft.

Does this create problems or does the odd shape of the room and the variance of 5 or so inches make enough of a difference?

The ceiling height had the choice of being 7 ft for 50% of that room and then about 7.8 ft for the other portion, but there would have been a hard vertical edge for the HVAC soffiting. I figured it was probably best to lower the whole ceiling, but I could be wrong.

The back of the control room suffers from the same thing... the bottom wall has soffiting around HVAC that goes the full width of the CR along the CONCRETE wall... The framed ceiling at that point is 7' while the remainder of the control room is 8'.

Thanks,
Jim