what's wrong with this picture?

Well, I've been doing a lot of reading here. A wealth of info - Head is spinning. But first things first. I need a basic plan THE DETAILS: (Feet & Inches) - This is room attached to a home with staggered studs and insulation. (also separate entrance) - Remaining 3 walls are concrete cinder block. (filled with acoustic foam) -17' x 15' x 8' (cathedral ceiling to 10') -Nearest neighbor is 30' away - Next nearest neighbor is over 100' away - Quite suburban street. THE NEED: - Split the space into mostly a control room with a small performance area for the occasional voc/voice over/ gtr amp. (No drums or live bands) - Would like to isolate the control room even more from the house - Volume shouldn't exceed much more beyond a typical home theater blasting an action film. - Control room needs to accommodate several keyboards, control24, 3 monitors plus all the other usual stuff. THE FANTASY: -Would like to place wall(s) so as to make the most use of the space. - Keep design simple, but provide more soundproofing to the house. THE PROBLEM - Perhaps my design idea is too simple? - What can be done with the ceiling? Is there enough room for bass traps up there? - And then there's the issue of possibly two glass windows on opposite sides of the room facing each other..... (be gentle, I'm new here) Feel free to download and modify the Skeetchup file. (clik on the tabs for more info) Thanks for any assistance.

It lends itself to a straight forward layout like this. cheers john

Thank you so much for the quick response. Isn't the internet wonderful? CLARIFICATION: - All the extra walls are regular stud walls? - Is that a floated floor? I will work with this design for awhile. Maybe there's a plan 'B' for how to deal with that outside window? I will return when it's time for acoustic treatment and a discussion about the ceiling. Thanks again. Thomas Anthony Natural Sound WWW.NaturalSoundRecording.com

A couple more questions 1- I understand the stud wall along the 3 outside concrete walls. But is that also another stud wall on the wall that joins to the house? (the wall opposite the wall with the window) That wall already has a staggered stud wall. 2- Is that also a 2nd stud wall going around the bathroom? 3- I've been trying to read up on the STC's of various stud wall combinations. I haven't found what I would lose if I redid those 2 walls with Green Glue on the existing stud walls instead of adding a 2nd stud wall. (trying to save every inch that I can) Probably more questions to follow. I have more reading to do. Thanks again Thomas Anthony Natural Sound

OK- Let me ask it this way. Although I've found many examples of STC values for Greenglue vs Walls. I can't quite find the values for my situation. QUESTION 1 Does anyone know what the STC of the following 2 scenarios might be? PIC 1- Existing exterior walls PIC 2 -To the existing walls add GREEN GLUE and 5/8" drywall OR INSTEAD OF THE GREENGLUE: PIC 3- To the existing walls leave 1" space and build a metal stud wall with 5/8" drywall QUESTION 2 Which would be the most economical to build. (price per sqft)?

PIC 3 is a triple leaf. It is bad. The STC would be in the 60s. In other word flanking will be your limiting factor for sound isolation. Andre

Thanks, The lite bulb just went off. I finally found the thread that discusses this: http://www.johnlsayers.com/phpBB2/viewt ... riple+leaf After reading that, it looks like it's best to just leave those 3 outside walls alone. Mass, air, mass - Now I get it. New question coming up tomorrow. Still reading. Lots to learn. thanks.

Ok- forget most of the above and lets start here. MY THINKING: The wall on the left is a staggered stud wall joining the studio to the house. The wall on the right would be new construction (I'm abandoning the dbl wall construction for budget constraints) I was going use 2 layers of drywall with GG on both walls. and then add either T&G cedar or 4'X8' decorative plywood to one of the walls with fabric panels on the opposing wall. MY QUIZ QUESTION for today is: Is there any diff between using 2 layers of 5/8" drywall with Greenglue and using one layer of Drywall and one layer of Plywood with GG? In other words, can I eliminate one layer of drywall, and GG the plywood directly instead? Will this increase , decrease or not change my STL? Any preference as to which wall should get what? as always, thanks for anyones time.

MDF has a higher density then plywood. A 1/2" sheet of MDF is higher in density then 3/4" plywood. I would use MDF over plywood. If I was having thoughts of which to get, I guess I would go all out and just get all 5/8" rock. If still torn, then MDF would be next. If a pinch existed, then OSB would get the nod. Plywood wouldn't be on my list of things to use for mass in a wall. http://www.johnlsayers.com/phpBB2/viewtopic.php?p=51414

Thanks Xspace. So a 5/8"drywall- GG- 1/2" MDF sandwich would be as good (maybe better?) than 2 layers of 5/8" drywall and GG? Anyone else? In the meantime, I'll be down the hall studying your Weights/densities link. Always a wealth of info around every corner down here. Thanks,

UPDATE Ok- So I see that MDF is slightly lighter than drywall. So here's my latest plan culled from the many hours that I've spent studying here. SOUNDPROOFING --What I Know -- - As already stated, I'm forgoing the dbl wall construction between the performance area and the Control room. I'm more concerned with sound to and from the house than this small area. So I'm hoping that the extra drywall and thicker glass on the sliding glass door will do the job. (see pics below) - I know that flanking through the slab will still exist -- What I Don't Know- - Ceiling.- There's an attic space that's goes over both the house and studio. Should I add a 2nd layer of drywall with GG to the ceiling? - Window - The window faces the back yard which borders a forest preserve. Will I suffer any consequences if I leave this as is? ACOUSTIC TREATMENT. The sketchup file has grown to a point that it's girth prevents it from being uploaded here anymore. I'm suppling 4 screen shots. Any thoughts before I hand this over to the contractor to sort out the finer details.

Man, there's a lot of tumbleweeds down here.

Ok- So that brings us to the dreaded budget. We're working with $8K USD. What we know: HVAC modification will run $2800.00 Sliding glass door as pictured runs $1700.00 That leaves $3500.00 left to do what is pictured above. Still need suggestions regarding the 2nd layer on the ceiling as mentioned above. Is this do-able? Do I need to cut corners somewhere? Or am I :horse: (couldn't resist using that) But seriously - Hope someone can help.

"Ceiling.- There's an attic space that's goes over both the house and studio. Should I add a 2nd layer of drywall with GG to the ceiling? " You should add more mass to the ceiling, yes. Only you know what you are up against with the levels of sound in this overhead area. It is on your mind, maybe it is a big source of noise? You could(should) look into some of the methods used to decouple the ceiling from the existing framework. My guess is that you are having issues with sound coming in from overhang soffit vents and possibly roof ridge vents and all those other openings in a house roof structure. Maybe the street noise is making it in, lawnmowers, leaf-blowers and fast moving vehicles? edit:overhand changed to overhang :)

Thanks xspace. Right now, the room is just an empty space, Drywall walls, ceiling and concrete floor. I'm not worried too much about sound coming in through the attic/ceiling structure, It's just way too quiet around here. No road noise, Back of studio faces a forest preserve, no jet path, (only an ocasional prop plane),etc. But since it's so quiet, any noise from me might affect at least 1 neighbor that's about 25 feet away, and probably more importantly, the rest of the house. And yes i was thinking about the overhang vents. I have no way of testing the room at this point, so i'm just trying to cover all my bases. I'm primarily inquiring if this is a common problem amongst home studio's and is a 2nd layer of drywall with GG worth the extra time and expense. Those here that are building these studio's on a regular basis, might have some data regarding the sucess or failure of such endevors. I guess everyone is on board and approves of the rest of my problems regarding more isolation from the joining wall to the house? In the meantime, I'll research the ceiling decoupling subject. Although, at this point, maybe that part is a done deal already. thanks again for your thoughts. Hope to start constuction by Feb. 09 Lots to do.

Hi again Thomas. If you spend any amount of time and material on walls the ceiling should get this same attention. It can become the weakest link in your isolation. Noise can creep out and noise can fly in. A 5/8 piece of rock on the ceiling is typical in a house, but it should more mass if isolation is the goal. It is just a wall, laid horizontally ;)