Design Review

Michael - RE: soundproofing, and STC ratings - In case you've forgotten, check out the STC charts at John's site

http://www.saecollege.de/reference_material/index.html

- just remember, STC doesn't take into account anything in the bottom two octaves so won't predict results for trains, trucks, or incoming mortar rounds. (Or kick drum/bass getting out)

Pro studio builders use a really expensive recording sound level system for several weeks on a site before deciding how much sound control they need. I've only briefly considered doing something like that with a PC, a large hard drive, and a pgm like Samplitude that will let you do lower sample rates and record til the drive is full, then looking at the (time) compressed WAV file to find the peaks, and looking at the time code to find out when they happened - I think for most semi-pro use, that would probably be overkill and noisy periods could be worked around.

If I remember correctly, when you narrow the space between studs on any given wall plane to less than 2', the sound proofing gets worse. A certain amount of flex improves bass absorption... Steel studs generally are better than wood, because they flex in the middle and lessen the transmission from inner to outer wall surface, or vice versa. (Plus, no knots to nail into...)

As far as another wall inside, I'm still trying to fathom that one. On the studiotips.com site, there is a really bright acoustician named Eric that has designed major venues in europe, who continually cautions against "tripple leaf" walls as being detrimental to sound deadening. I'm eventually going to post a request for more clarification on that one, but as yet have not taken the time to even try to understand it first, much less post a "less than totally dumb-ass" question. Eric is from the Netherlands, and I have to work sometimes to follow his comments. (In all fairness, his English is about 500 orders of magnitude better than my Dutch...) He brings up things like % compression of rubber in order to actually achieve the isolation you think you're getting, how the figures for compression assume you're not "containing" the side walls of the rubber, which will stiffen it, etc, etc -

Just in case you weren't already buried in enough details... Steve
 
Mirror on the floor

Hi Michael, a reflected ceiling plan is your floor plan as a mirror. Imagine a mirror the size of your whole floor plan. Look at it just like the floor plan, in plan view. But a mirror reflects what is above. Hope that helps. And in regards to an ART DECO ceiling,
check out old theaters. There are some great ideas in these old masterpieces. They tore down one of the oldest here where I live about 10 yrs ago. It was magnificent. But I don't know how ideas like these work in regards to acoustics in the control room.
I know what you mean about multi-layered though. I've had to detail a couple. If its what I think you mean, they look great. They are not easy to build though, expecially if the ceiling is sloped or some acoustical requirement is inherent in the room, or you are using curves, and you try and work around it. I've imagined even cove lighting, or valances, but again, not being a studio designer, I have no idea of the consequenses of using such things in a studio or control room. Sure would like to use them, and a lot of other display things I have seen in my years as a store fixture designer. Cool materials are whats happenen!, hey, that reminds me of some waycool aluminum extrusions I have and can order. From a company called Stylemark. 1000's of extrusions, in 500 colors, and 12' lengths. They will even CURVE THEM if you want. But how deep are your pockets! I use them in my studio. For lots of things. My console, rackmout cabinets, graphics, etc. They are GREAT. most have a backer plate you screw to what you want, and then the extrusion snaps on. You can even make giant crown mouldings in different colors. Oh well, I just love all kinds of unusual materials. Stainless steel, perforated metals, plex, laminates, hardwoods and veneers. Even solid surface countertop materials. And ESOTERIC HARDWARE. I'm a hardware freek! My wife is ready to disown me cause of my collection of brackets, hardware, nuts and bolts etc. I even hung a antenea truss in my control room and made some brackets out of bicycle handlebar connections to hang my mic stands from the truss. Keeps things off the floor, and looks too good I even save all kinds of styrefoam packing, especially from electronics. Just gel-coat and paint them and mount them on the wall. With enough of them, and different patterns, I always thought they would make great STARTREK type wall surfaces, may even work like diffusers maybe, maybe not, but thelook woud definitely be unusual..enough already.
fitz
 
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Michael,
For your HVAC you might want to consider a "Package Unit." This is a completely self contained unit (compressor, blower, heat strips, etc). The whole thing sits outside and is ducted inside (both supply and return). Looks like a great way to keep as much of the fan noise outside as possible. Go to some sites like
http://www.carrier.com
http://www.rheem.com
http://janitrol.com
etc
Click on "package units". Within package units click on "heat pumps" if these work good in your area.
I will be using a package unit for my new building.

Also, to determine what tonnage unit you will need go to http://www.heatload.com Click on the "conventional forced air" selection. It will ask for room dimensions, insulation ratings, exposed walls, windows, etc. It will tell you how many btu's of heat loss you will have in the winter (in my case - 15234 btu) and how much heat gain you will have in the summer (in my case - 8247 btu). Even goes into detail as to whether or not your ductwork overhead or underfloor is exposed. Does multistory also. Note: 1 ton = about 12000 btu. I'll confirm my numbers with someone who does this for a living but it looks like I will get a 2 ton unit. Of course 2 1/2 to 3 ton would give me a little more breathing room. We'll see. Hope some of this helps.

DD
 
If I use "staggered stud" construction (2"x4" on a 6" base plate) on the exterior walls, and 2"x4" studs with reselient channel on the interior, what kind of STC rating can I expect?
Click to expand...
If one side differs from the other:

  • Side 1 - 5/8" Gypsum
  • Side 2 - Soft Fiber Board then 5/8" Gypsum
  • Caulk all Joints and Perimeter

STC 42 - Without Insulation
STC 47 - With Insulation (Properly Filled)

On the other hand, a double wall can get you as much as STC-55 if sealed and properly filled with insulation.
 
I tried an experiment today. I have one of these hand held sound level meters, and I took some readiings at the studio location. I measured an average of about 68 to 70 db with peaks around 82db. At least, now I have some idea as to how much attenuation of noise I'll want to have.

Which leads me to a question. If construction provides me with an STC of ...say somewhere in the neighborhood of 54, does that mean I will have attenuated 54db of ambient outside noise??
 
maybe... maybe not...

all of the exterior walls/ceilings need to at least have the rating your after.

also note that the STC rating does not mean that you get that transmission loss for all frequencies. STC is a compromise for the sake of ease of use. the actual STC is the walls Transmission Loss measured at 500Hz.

so, you may be disappointed with low frequency infiltration into the studio as the STC curve attenuation is generally much reduced in the lower frequencies. but, of course your gain (or loss) is much better than not having the STC
 
OK, I understand, a little bit better now. Are the sound levels I'm getting high, low, or typical of residential environments?
 
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