John Sayers' Recording Studio Design Forum

Following on from my thread in the Studio Design Forum: http://www.johnlsayers.com/phpBB2/viewtopic.php?t=4552

Having had the weekend to absorb the new design and think over the project in more detail, I have some new questions; which are open to all here with experience to answer:

1) By using sliding glass doors in some of the walls, I think I am right in thinking that the rest of the wall need have as high an STC rating as the door itself (since the wall will only be as good as the weakest link etc.) Therefore; does anyone have any idea of the STC rating of a sliding glass door? I seem to recall reading here that the Pella doors work okay. Does anyone have any experience with the STC of such doors (or others you can recommend), and the resulting wall structure method around the door? For the External walls I will be using RC, Sheetblok and 2 layers of drywall. I'm going out on a limb here in assuming that might be overkill for the walls that have sliding glass doors in them.

2) I was hoping to use track-lighting in both the live and control rooms. Additionally I would like to use dimmers (for mood lighting). And finally I was hoping to activate them remotely. I have been using X10 products elsewhere in my house with somewhat limited success and wondered if anyone had an experience as to the silence of i) Track lighting ii) Dimmers, and iii) Remote control diming products such as X10's or others.

3) A/C - In the basement there are currently three A/C outlets I beleive, but no intake register. I wondering whether I need to get an A/C guy to come out and look at installing this as it would seem to me that with my new "airtight" rooms; I will be blowing air into them, but will have no way of removing the stale air. I'm not sure how this works, whether it causes a build up of pressure or indeed whether an outlet is necessary in each of the rooms, but would really appreciate some insight and pointers from the community here.

4) Floor - I had read here that building a floating floor poorly is worse than not trying at all. With that in mind, and noting my limited ceiling height (currently 7ft4 before adding new ceiling); do you think I can survive without floating the floor? With John having created a seperate room between the drum room and the control room; do you think this will give me enough isolation without having to float the floor? As some background; I am hoping to use a laminate style flooring throughout the studio. I have also read elsewhere that for basements one must always use an underlayment that controls moisture.

5) For the ceiling, Height is at an optimum as with most basements. I have about 7ft 4. I was planning on removing the existing drywall ceiling, re-using the drywall if possible to add an extra layer between the joists to the floor above, then stuffing with insulation, and then using a combination of Resilent Channel,sheetblock and drywall to cover. Would this seem to be sufficient to you? Will the RC be able to support the weight of the Sheetblok and drywall? Should I use two layers of drywall or just one?

6) I was planning on figuring a way to use my 30 channel snake between the CR and live room, but considering the additon of the extra room, and the challenge posed by getting the snake through the wall without compromising the walls soundprrofing quality, I am now leaning more towards using wall plates. Does this seem to be best? If so - can anyone recommend a supplier for these?

Finally, with my new design in mind, using the sliding glass doors, I will no longer be needing my Acoustical Solutions window that I had bought; so if anyone needs one; feel free to drop me a line andy_eade@yahoo.com.

Thanks in advance for your help.

Andy

Reference my questions 1 and 5 - having been researching some other projects here on the forum, I am starting to question whether I have been brainwashed into thinking that I should be using Sheetblok as a part of my wall and ceiling construction. I read here that some people have used other (much cheaper) products with great success.

I was planning in using this competitors version of sheetblok:
http://www.soundsuckers.com/barriers.htm#barriers

But am wondering if anyone here can comment on the cheaper and comparable alternatives. It seems as though from some of the wall construction methods I have read, including Knightfly's reference section, that sheetblok (or similar) is not used. Just two layers of drywall.

Thoughts?

Hello there. Yes, to answer your question, it should be noted that drywall performs equally, if not better, than sheetblok (mass loaded vinyl). The idea is to have extra mass for your walls to help with noise levels. Drywall is at least as dense as sheetblok. While there may be some sublte advantages to having different materials within your wall (sheetblok, drywall, etc..), there are many tests that show that walls using only multiple drywall layers perform just as well as walls with sheetblok. Not to mention the huge price difference between drywall and sheetblok. I know there is a thread in the reference section about this very topic but I can't remember exactly which one. Try doing a search using "Sheetblok" or "mass loaded vinyl" as your key words. Hope this helps a little.

Indeed. Here's my favorite thread on why MLV is a waste.

Thank you so much for saving me thousands of dollars. This forum fills a real void and helps people like mine's dream become more like reality - so thank you.

Sharard - I read your fave thread on MLV with interest and am now very happy to change my plan to exclude the MLV layer in both ceiling and walls.

I did have one question though that I was confused about. In the thread it mentions using 4 (or maybe more) layers of wallboard, but I seem to recall reading here in another thread that there is a point of diminishing returns where you actually begin lowering the STC by adding layers. Did I imagine that or does that sound right. Maybe I misunderstood and he was talking about the layers on the other side of the framing?

Also, any thoughts on my other questions in my first post?

Thanks again.

Andy

More mass is always a good thing. More air gap between the two leaves is always a good thing. There is a kind of "bang for your buck" in terms of the air gap -- 12" is excellent. More is better, but additional inches aren't as noticable... So I'm told.

Makes sense.

So here is what I am thinking in terms of my wall plan.

RH Drum room wall (By stairs) - from right to left: 2 layers of 5/8ths wallboard on RHS of existing frame, no RC, then insulation. Then, frame new wall 4" out from the other one. Stuff with insulation, RC then 3 layers of 5/8ths wall board.

note: also considering building storage into the space under stairs. Anyone have any experience of doing this? How hard is it to do whilst maintaining the integrity of your wall's STC rating?

Walls between CR and Booth, and Drum room and booth (with sliding glass doors): 2 layers of 5/8th, insulation, rc, 2 layers of 5/8th. Question: By doing this, will my booth have comitted the crime of a quad leaf design? or is the space in there big enough that it will not be a problem?

Other perimiter walls (i.e. drum room bottom wall, left wall etc.): These walls are external walls that are painted cinderblock (hopefully not hollow - any idea how I can check?). They are currently covered with that oak paneling, and hence the "framing" is done with I think with 1x2's (I think that's what they're called anyway. Bottom line - they are much smaller than 2x4's). I was thinking that I would just remove the paneling, put in some very thin insulation (1 inch probably) and then 2 layers of 5/8th.

Ceiling: From upstairs down: Upstairs floor finish, subfloor, joists etc., stuff old drywall (removed from old ceiling) between joists to add mass, RC, 703 (or equiv), 2 x 5/8th drywall.

Question: Should I be putting anything between the RC and the ceiling joist? I had ready that some people are using thin strips of rubber of GAF try ply.

In all multiple layers of drywall, drywall will be staggered so that seams do not line up. I had read one to rotate drywall 90 degrees each layer, but staggering seams to make more sense no?

How does my plan sound? I'm hoping if this is okay to present it to the General Contractor next week and get an estimate on labour cost and time to complete.

Here is the plan diagram that goes with the notes above:



Many Thanks,

Andy

IF you have separate (double) frames, don't even THINK about using RC - it's a PITA and does NOTHING. Should only be used on ONE side of single frame walls with panels on BOTH sides of ONE frame.

Don't bother putting tri-ply or anything else under RC when used on a ceiling or wall; on walls especially, that will just let the RC sag more and mess up your caulking by too much movement.

It's not that MLV is actually BAD, it's just too expensive for anything except EXTREMELY tight spaces where you need the mass without thickness. Most studios are built on more of a budget, and that extra 1/2" of wall thickness isn't going to make a difference compared to the difference in cost.

Gypsum wallboard has different bending strength the long way vs. the short way; for this reason, you should BOTH stagger AND rotate subsequent layers. On walls, the last layer should be horizontal for easiest finish and best looks (flatness) - so if doing 3 layers, they should be horizontal/vertical/horizontal. For two layers, do vertical first. Offset ALL joints by one stud cavity minimum, in BOTH axes.

I've updated the link to the USG manual in the REFERENCE section; you'll need to register to get it but it's well worth the hassle... Steve

Great - thanks so much Steve. I am updating my plan for the General Contractor. I will remove the RC from the side wall by the stairs and use nothing under the RC.

btw - forgot to mention in my post that I am going to take a gamble by not floating the floor since ceiling space is so limited. I figure this would be better than floating it poorly and wasting a shedload of $$$.

Thanks again, and I will post more news as progress is made.

Thanks.

p.s.

Anybody with thoughts on my AC / lighting questions etc back in top post - please feel free to chime in

Lighting - I've yet to find an electronic dimmer that's quiet - most even vibrate the filaments in the lights for more mechanical noise. Only sure way is variacs, which are neither small nor cheap.

Did one studio with just separate circuits, including one with just flourescents behind the racks for work lights - for mood, we kept the bulbs small in a couple of circuits (gel holders in front for color) and just switched on as much light as needed.

HVAC - what goes in must come out. I'd use your local HVAC guy, don't let him talk you into oversizing anything EXCEPT the size of ducting. If the air isn't balanced for pressures, it won't work. Oversizing the ducts/registers will lower the air noise a LOT, but oversizing the unit will cause short-cycling, and you won't get enough dehumification to combat mold/mite growth... Steve

One last (2 part) question I have thought of as I am writing notes down to present to the General Contractor.

For the walls of the booth that contain the sliding glass doors, I am planning on two layers of wall board either side of the frame.

Q1) Is it worth using RC on one side? I mean, I'm assuming that the door will be the weak link in the chain, and I'm wondering how much so. i.e. would I be wasting my money on the RC?

Q2) In my two layers per side, I was planning on using 1 layer of 1/2" and one layer of 5/8". Does it matter which one is on the outside?

Many thanks experts for your help again.

Andy.

I think conventional wisdom around here is to actually use two layers of 5/8", rather than mixing and matching 5/8" and 1/2". While there are some marginal benefits to using different thicknesses for mids and highs, having just plain "more mass" is more beneficial for the lows, which are harder to contain and arguably more critical to try to isolate. There is also the added benefit of only having to work with a single thickness, which means you only need one stack of the stuff from which to work -- a plus when you're pressed for space in a cramped construction zone.

Consider the use of [url=http://www.audioalloy.com/b10-00_products.html[/url]Green Glue[/url] between the layers.

Your question about the sliding glass door being a weak link is a good one -- one I'm not qualified to answer. I'm sure someone here can though.

Okay great - low is definitely what I'm looking to reduce as much as possible so 2 x 5/8ths it is. The added benefit of simplicity is always nice too!

As for the green glue, what is the $ to STC ratio. i.e. what kind of improvement do you think I can expect for shelling out the extra cash?

Hopefully someone else can chip in on the RC question above.

Thanks as always for your guidance! =) Hope you're enjoying the Holidays!

Andy

Check out my "Would Green Glue Save Lot of Work/Materials on My Ceiling?" and the "Definitive word on Green Glue?" threads over on StudioTips. Also, there's my post regarding my experience so far with Green Glue.

Be prepared for some sticker shock. The stuff isn't cheap. But, then again, good solutions rarely are!

--Keith

Thanks Kieth. Wow it's really amazing to me that every time you think you have your final plan, something new pops out of the woodwork and makes you realize how much better you can make it.

So now having ready your links with great interest I think I will be dropping the RC in both Ceiling and Booth walls in favor of the Green Glue.

I worked on typing up a document last night for the General Contractor with a wall by wall plan along with some tips and pics that I have picked up from this forum.

<b> So here it is, my now final (until the next a-ha moment) plan: </b>



1. RH Drum room wall (By stairs) - from right to left: 3 layers of 5/8” wallboard (horizontal, vertical then horizontal) on RHS of existing frame, insulation stuffed into existing frame. Then, frame new wall 4" out from the other one. Stuff with insulation, then 3 layers of 5/8” wallboard (horizontal, vertical then horizontal).

For all walls - Each layer of wallboard should also be offset by one stud cavity along with the horizontal / vertical alternations, and Green Glue should be used between the final layers.


Note: Gypsum (most of it, anyway) has its long edges tapered for mudding and taping joints; in a multi-layer application, if these are not filled entirely so there are no VOIDS, it will weaken the wall in two ways - it creates a small air gap, which will have its own audible resonance/weakness, and it lessens the MASS of the leaf which will lower effectiveness.
½” gap 1/4" to 3/8" gap should be left at the floor and filled using foam backer rods and acoustical caulking.
Drum Room Door – 2 solid core doors one on each side of the door frame. Air tight seal all around and to Jam.
Question – what kind of door handles? i.e. no holes in door.

http://www.johnlsayers.com/phpBB2/viewt ... atch#30766


Note: Sound slips through even tiny gaps which might seem to you to be insignificant, so it’s of extreme importance to construct your place as airtight as humanly possible. When humanly possible still isn’t good enough, silicone Butyl or acoustic rated caulk can be of great benefit & save your you-know-what.

So, do the best installation job you possibly can & keep the caulking gun handy!

A common use for caulk or expanding foam sealant is to seal the holes in studs where wires go through or at the back of electrical boxes where wires enter. Believe it or not, these small openings can sabotage an otherwise excellent wall, so don’t overlook them. (see diagram below)
Never mount electrical boxes or connector panels back to back; always stagger them as shown in the diagram. Seal the holes your wires go through and/or run wire through conduit (PVC is great for this), stuffing foam or insulation in the ends to help seal the conduit so it doesn’t resonate. Isolating the PVC from the structure with SheetBlok or hanging it via rubber "bungee" cords (tie-down straps, which are available at your hardware store) can really offer some improved isolation.

2. Other perimeter walls (i.e. drum room bottom wall, left wall etc.): These walls are external walls that are painted cinderblock (hopefully not hollow - any idea how I can check?).

Drop down at least two blocks from the top and drill a hole - if these are 8x8x16 blocks, drill halfway between top and bottom and 4" from one end of the block. If you don't hit air after 1.5", repeat this in the same position one FULL block horizontally - if you still don't hit air, they're probably filled. However this is fairly rare; usually they just fill thei tops so sill plates can be attached.

They are currently covered with that oak paneling, and hence the "framing" is done with I think with 1x2's (I think that's what they're called anyway. Bottom line - they are much smaller than 2x4's). I was thinking that I would just remove the paneling, put in some very thin insulation (1 inch probably) and then 2 layers of 5/8th.

This will probably create a 3-leaf situation - unless your test above shows solid filled blocks, or unless you decide to drill ALL the blocks and fill with sand.

3. Walls between CR and Booth, and Drum room and booth (with sliding glass doors): 2 layers of wallboard (5/8”) glued with Green Glue, single frame, insulation, 2 layers of wallboard (5/8”) glued with Green Glue. Horizontal / vertical and staggering principals need also apply for this wall. For this 2 layer wall Vertical should be done on first layer and horizontal on the outside layer. Single frames, and no resilient mounts? RC was first used to isolate human VOICE, and is in fact useless at low frequencies but works pretty good to isolate midrange...

4. Rear Lounge wall – Just replace wood paneling with drywall.

Ceiling: From upstairs down: Upstairs floor finish, subfloor, joists etc., stuff old drywall (removed from old ceiling) between joists to add mass, 703 (or equiv), 3 x 5/8th drywall (last layer glued with Green Glue). For inside of walls/ceilings, plain old spun fiberglass slightly compressed works just as well and cheaper than 703.

Here is an updated floor plan with the numbering to match the above: