Post production, training & recording facility - layout

Ok, thanks So please confirm I've got this basic understanding correct Corridor and Rear CR wall: - 2 layers of 16mm drywall - studs (insulated) - 2" Air Gap - studs (insulated) - 2 layers of 16mm drywall Concrtete wall: - 1" Air Gap - Studs (insulated) - 2 layers of 16mm Storage room wall: - Existing Single Stud wall (insulate) take plasterboard off? - 2" Air Gap - Studs (insulated) - 2 Layers of 16mm Ceiling - Air Gap - Insulation - 2 Layers of 16mm What about RC - should I use it for the extra few db? Will this give me the level of STC I would need as there are offices on the concrete wall side and a pub on the corridor side and a busy road / bus route on the training room side? Also what about the floor, should I maybe float the live room to avoid flanking? The advice is hugely appreciated

the ceiling is on joists supported by the inner isolation walls. the ceiling is (from inside to outside) 2x 16mm, joists 1 layer of 100mm rigid insulation then fill with pink insulation, air gap, overhead concrete. storage room wall (from inside out) 2x 16mm, stud, 4" rigid insulation, 1" gap, stud (existing), 4" rigid insulation, 2x 16mm for the floor, if you have Rod's 2nd edition book on home recording studio construction, he has put forth a nice option: put down 2" of 48kg/m3 rigid insulation then on top, 2x 12mm plywood, then your flooring (say 12mm engineered wood). this all sits within the inner isolation walls and is separated from them by about 12mm. if you think you need the walls isolated as well, he has an example using Mason Industry ND isolators on a sleeper to isolate the walls from the floor. this combination should give you substantial isolation but will take more work.

What about RC - should I use it for the extra few db?

There are are no more "extra few dB" in there! If you are decoupled then you are decoupled: decoupling again serves no purpose. That would be about as useful as using an umbrella indoors: the roof already stopped the rain, so you don't need the umbrella too! Same thing: if your walls are correctly decoupled, then RC won't buy you any more isolation. - Stuart -

Ok, thanks. What about using green glue between the layers? Also

One2one2 wrote:

storage room wall (from inside out) 2x 16mm, stud, 4" rigid insulation, 1" gap, stud (existing), 4" rigid insulation, 2x 16mm

It's pretty difficult to add a second layer in the storage room - as the inside of the store room has been plastered, painted and wood shelving has been put up all around the room from floor to ceiling. The shelving could be taken down and another layer of wallboard put up - if that's the only option. I'm assuming if we put the second layer on the inside between the studs that would create a third leaf? Another problem is on the other side of 1/4 of that wall is the stairs going down, the builders have dropped the ceiling above the stairs and never boarded above it - see the picture below. So impossible to add another layer from the other side without pulling down the ceiling? What would we have to do? Thanks

I'm assuming if we put the second layer on the inside between the studs that would create a third leaf?

No it would not create a third leaf, and that is exactly what Glenn is referring to. This is what is called "beefing up". It means that you carefully cut strips of drywall to fit IN BETWEEN the studs, hard up against the drywall on the other side of the studs. Meaning that there is no air gap between the new strips of drywall and the existing drywall. Tye are in direct contact. Do not glue them! You can use Greenglue if you want, but not glue. Hold them in place with cleats, and seal around the edges with caulk. You can do two layers like that if you want. - Stuart -

Great! Well thats what thought I could do, cut strips of board to fit in the stud and put cleats in, but glenns comments about this wall earlier on threw me a bit

gullfo wrote:

beef it up on the outside and use it as the outer leaf. 2x 16mm plus insulation etc. do not add the second layer on the inside or you will create a third leaf.

cool, I just mis-understood! I'm now good with the walls and ceiling, Thanks for all the breakdown of it!! I now need to decide whether to float the floor or not?? From what I have been reading, I'm leaning towards not floating - but I well continue investigating. Thanks guys

cool, I just mis-understood! I'm now good with the walls and ceiling, Thanks for all the breakdown of it!!

Yup! What Glenn was saying is to not put drywall on the side of the studs facing towards the room! That is what would create your third leaf. Technically, a "leaf" is just a large solid massive surface with an air gap next to it. If there is no air gap, then it isn't a leaf.

I now need to decide whether to float the floor or not?? From what I have been reading, I'm leaning towards not floating - but I well continue investigating.

Maybe these will help you decide: viewtopic.php?f=2&t=8173 http://www.nrc-cnrc.gc.ca/obj/irc/doc/p ... /ir802.pdf Read them both carefully... :) Questions: 1) Your existing floor is concrete slab, right? How thick? 2) What is underneath you? 3) How much isolation do you need? (You might have already covered that before in your thread, but I'm feeling lazy today...) - Stuart -

green glue could help. both on the walls and the floor. on the section by the stair case, you might have to create a small section where you beef it up as much as possible and 3x 16mm on the inside part of it to ensure it's sealed. you'll possibly have a third leaf situation on a small portion of the wall but it might be the only way.

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Soundman2020 wrote:

Questions: 1) Your existing floor is concrete slab, right? How thick? 2) What is underneath you? 3) How much isolation do you need?

1) Yes concrete, about 1 and a half foot thick 2) We have a audio equipment store below us, (that we own) music and noise playing throughout the day, people demoing gear etc. So not bothered if a faint kick drum / bass comes through downstairs - just not the other way, hearing noise on the recordings is a no no. 3) Critical isolation is the offices on the other side of the north concrete wall, if they can hear anything, then its game over My reason for considering floating are 1)more isolation between floors, 2) more isolation from nextdoor and 3) Flanking between Live room and CR Also could I beef up the concrete wall to ensure the isolation is sufficient or would that not make much difference?

Also could I beef up the concrete wall to ensure the isolation is sufficient or would that not make much difference?

Well, you could, but you'd need an awful lot of drywall to make any difference! IIRC concrete is about 3 times more dense than drywall, so assuming that your wall is about 6" thick, then adding 18" of drywall to that would theoretically give you an extra 3dB of isolation. That would be something like 30 sheets of drywall.... :shock: In other words: beefing up concrete is almost pointless. Not needed, won't make any difference at all. However, where you CAN make a difference is to put more mass on your inner leaf. More layers there will definitely improve things: Ideally, the masses on each leaf should be the same, but you already have so much in the concrete that you don't need to go to incredible extremes. Probably 3 layers of 5/8 with GG, plus a large air gap (say 10") will get you pretty decent isolation. And fill that cavity with as much insulation as code allows and you can afford. There are studies showing that fully filling the air gap with insulation can gain you anywhere up to 16 dB of isolation. I'd also think of putting drums and amps on risers, and perhaps even using Rod's new suggestion for floors: Glenn outlined it earlier, a few posts up. That should give you the extra bit that you need to keep the impact noise out of the building structure. - Stuart -

Thanks, will decide shortly - but leaning towards just building risers if we need to at a later date. What about acoustic board underlay under the laminate that must help somewhat towards impact noise? Also what are your thought on the this silencer that the previous designer did?

gullfo wrote:

for the floor, if you have Rod's 2nd edition book on home recording studio construction, he has put forth a nice option: put down 2" of 48kg/m3 rigid insulation then on top, 2x 12mm plywood, then your flooring (say 12mm engineered wood). this all sits within the inner isolation walls and is separated from them by about 12mm. if you think you need the walls isolated as well, he has an example using Mason Industry ND isolators on a sleeper to isolate the walls from the floor. this combination should give you substantial isolation but will take more work.

:idea:

Also what are your thought on the this silencer that the previous designer did?

Not very good! It does not force the airflow to change direction, and there is a direct sound path from inlet to outlet. It is also rather complicated to build, and the box construction is unnecessarily complex. Use one of the many tried-and-tested designs here on the forum. Simple, and very effective. - Stuart -

gullfo wrote:

gullfo wrote: for the floor, if you have Rod's 2nd edition book on home recording studio construction, he has put forth a nice option: put down 2" of 48kg/m3 rigid insulation then on top, 2x 12mm plywood, then your flooring (say 12mm engineered wood). this all sits within the inner isolation walls and is separated from them by about 12mm. if you think you need the walls isolated as well, he has an example using Mason Industry ND isolators on a sleeper to isolate the walls from the floor. this combination should give you substantial isolation but will take more work.

Yeah! That's an idea. Was concerned about the loss of the height though, especially if we did the CR as well?

Soundman2020 wrote:

Quote: Also what are your thoughts on the this silencer that the previous designer did? Not very good! It does not force the airflow to change direction, and there is a direct sound path from inlet to outlet. It is also rather complicated to build, and the box construction is unnecessarily complex. Use one of the many tried-and-tested designs here on the forum. Simple, and very effective. - Stuart -

Thanks will do, just wanted to confirm my suspicions that this designer doesn't know what he is doing! I spent most of last night reading on here about Hvac / ventilation - it's very complex and varies so much between installations. Is there a unit that does both ventilation and cooling / heating - or is it 2 separate duct works and a silencers job?

One2one2 wrote:

Yeah! That's an idea. Was concerned about the loss of the height though, especially if we did the CR as well?

it's only about 3" (75mm) when its done and you have about 9'2" (2.8m) below the ceiling drywall

gullfo wrote:

it's only about 3" (75mm) when its done and you have about 9'2" (2.8m) below the ceiling drywall

Ok, so not that much lost, would we have to change the length and width by 3" to keep it at 1:1.26:1.68?

i think that the difference in ceiling height is minor enough to leave the rest of the dimensions as-is. 1:1.29:1.73 assuming a 8'11" (2.72m) height. you could pull in the length 5" and width 1" to reset to 1:1.26:1.68. Maybe Stuart or John B could comment.

Hi guys For the last few days a have been planning out the electrical, lighting, HVAC / ventilation and silencers side of the install - will post the plans shortly. One other concern I do have with the design is the front window, as we will be doing a fair bit of post production as well as recording. I was thinking of having a pull down projector screen that goes over the window, but a very much prefer LCD over projection, which made me think that maybe I could get some kind of slide down LCD bracket of some sort - but with a lot of googling I can only find slide sideways brackets (mainly used in caravan's/ RV's etc) Anybody aware how this as been solved before? Images attached is a 50" lcd on an angle above the window, but I think I would get a bit of saw neck this way! Possibly make the control window smaller so can get the LCD down lower? I will also have 2 x 21" LCD for my DAW, which was thinking of sinking into a desk on an angle so not to block sight of the live room. You thoughts? Thanks

check out some of the swing arm supports which may be usable to put the TV up and out of the way. or conceptually, you could have it on a wheeled frame to roll it into place when needed, hook up the power cord and single HDMI cable and you're good. this way you could also use the TV elsewhere in the studio if needed. http://www.ergotron.com/Products/tabid/ ... fault.aspx

Thanks, gave me an idea of having an electric lift mount - like in bedrooms - were the TV pops up from the end of the bed in a cabinet of sorts. When looking for that I found these http://www.firgelliauto.com/default.php?cPath=108 http://www.firgelliauto.com/default.php?cPath=95 UK company http://www.ascendingvision.co.uk/acatalog/TV_Lift_Mechanisms.html I think the lift is probably best, I could build it into the back of workstation / desk or simply behind the desk - press a button and the screen pops up! Brilliant!!

keep in mind you probably still want to hear your monitors so consider the placement closer to the window than the desk. maybe there's an option also to have it lower instead of up? it's probably a screw gear drive of some kind so the manufacturer may have some ideas.

Yeah the ascending vision ones can be wall or ceiling mounted as well, so it could be lowered. If I lowered it - the cloud would have to be shorter - how would that effect the acoustics? Obviously I don't want to compromise the sound over something fairly cosmetic like this.

Your cloud should have around 12-14" (300-350mm) air gap all around so it should fit. If not moving the front edge back a bit more should be ok.

gullfo wrote:

i think that the difference in ceiling height is minor enough to leave the rest of the dimensions as-is. 1:1.29:1.73 assuming a 8'11" (2.72m) height. you could pull in the length 5" and width 1" to reset to 1:1.26:1.68. Maybe Stuart or John B could comment.

Hi Gullfo When measuring the length and width of the room, what are you measuring from to get the ratio 1:1.26:1.68? Is it the main double plasterboard rectangle walls or the from the splayed walls for the widtch and from the soffit and bass traps for the length? Thanks

the drywall (or other isolation boundary) is the measuring point. the treatments, even hard ones, are typically not considered in the ratio (although of course they do impact the room response...)