Construction Details

Michael Jones · Post by **Michael Jones** » Wed Jun 11, 2003 2:03 am

Sen wrote:
knightfly wrote: If anyone is in need of a PARTICULAR detail, feel free to ask - Steve
Do the wall plates have to be common for both frames (inner+outer) when building staggered stud walls, and is there anything similar to dead men invovled when not using brick?? Do you have to tie the frames togehter?

I don't know what you mean by wall plates???
What do you mean by "tie the frames together"?
Do you mean adjoining adjacent 10'-12' wall sections?
If so, what you do is make sure the last stud in one section is on the same side (preferably on the INNER, but its not crucial) as the first stud in the next section. You nail the wall frames together at that point. Also, when putting on the top cap, you make sure it overlaps at all corners, and spans all seams at joined wall sections.

I can post a pic if you don't understand....

knightfly · Post by **knightfly** » Wed Jun 11, 2003 3:21 am

I think what Sen is referring to is plates, as in plates and caps of the stud frame. The staggered stud wall, by definition, uses common (but wider) caps and plates - at least 2x6 horizontals (caps, plates) with 2x4 studs. Keep in mind, Sen, that this is NOT the best soundproof wall you can build - the next level up would be totally independent frames for each mass center to attach to - outside of the outer frame, and inside of the inner frame (unless you're building John's inside out wall) - this type of wall would have SEPARATE plates and caps for each half of the wall, inner and outer - that gives better isolation, since there is no common framing member between inner and outer leaves of the wall.

As to inner and outer frames being tied together, you don't want to do that with anything rigid as that will partially destroy the independence of the two masses. There are companies that make/sell acoustic braces that use a rubber joint surrounded in steel - naturally, I couldn't find the link when I went looking.

Fell asleep twice trying to write this, guess I better get some sleep... Steve

Michael Jones · Post by **Michael Jones** » Wed Jun 11, 2003 5:49 am

knightfly wrote:I think what Sen is referring to is plates, as in plates and caps of the stud frame. The staggered stud wall, by definition, uses common (but wider) caps and plates - at least 2x6 horizontals (caps, plates) with 2x4 studs. Keep in mind, Sen, that this is NOT the best soundproof wall you can build - ...

That's true. I wont refute that. BUT... the cross-sectional area of the sole plate and top plate is so minimal compared to the cross-sectional area of the stud wall that any sound transference from the sole plate to the stud, and thru a triple leafed wall is going to be negligable. Additionally, the sole plate is held SO rigid against the foundation that its doubtful (at least to me) that it would resonate at any discernable frequency.

A double exterior wall is definately better for isolation, but the costs go up considerably. And if you're using a vaulted ceiling, the degree of construction complexity increases greatly as well because the interior wall would need to be a few inches taller, and the top stud would need to be cut at the pitch of the ceiling. And you STILL have the link between the 2 walls at the truss.

Now, what you can do, or at least what i'm doing, is have a "belt and suspenders" approach!

I have a staggered stud exterior wall, and a separate interior wall!
This is limited to the control room though.
This puts this room in essentially compleate isolation.

knightfly · Post by **knightfly** » Wed Jun 11, 2003 9:54 am

Michael, first of all cool pix - are you getting close to "rockin' the house", or does it just look like it? Bought that "full auto" screw gun yet?

As to your comments on staggered studs vs dual wall - "And you STILL have the link between the 2 walls at the truss" - Not in the design I'm working on...

I agree completely about the complexity, and am working on a set of drawings (as I design them) to (hopefully) simplify that type of construction while maintaining two (almost) completely separate mass centers everywhere between inside and outside. I'm probably being optimistic when I say that this could take a while...

I have to disagree with your statement - "any sound transference from the sole plate to the stud, and thru a triple leafed wall is going to be negligable" - As near as I can figure out from charts of actually TESTED wall construction, there is a difference of about 9 dB - refer to the chart John posted here on march 01, re the STC 63 wall on the right -

http://www.homer.com.au/phpBB2/viewtopi ... 86&start=0

vs the SAE chart on STC -

http://www.saecollege.de/reference_mate ... 0Chart.htm

In the SAE chart, check the staggered wood stud with insulation and two layers of wallboard at STC 54. (Essentially the same construction, only difference being staggered studs/common plate/cap vs separate stud frames)

To me, 9 dB is about the same as putting the sound source 2-1/2 times as far away (which I would dearly LOVE to do with both my neighbors, since I can't talk the Lawnmower man into shredding Mr. "Dumber than his Dogs" and then turning the mower on himself)

From your earlier comments, it sounds like you don't need as much isolation as I do. In your case, I'd be going for the best method that's actually DO-ABLE without having even MORE stress attacks than you've already been through.

In MY case, however, if I shoot for enough isolation that I could target practice inside the studio with a .44 magnum at 2am without the neighbors (or my wife) hearing the noise, it should be just about the right amount. (Might be kinda hard on some of my condenser mics though... :=)

I think it comes down to each different situation (needed isolation, available cash, time, etc) requiring a different approach, more than anything... Steve

Michael Jones · Post by **Michael Jones** » Wed Jun 11, 2003 10:52 am

Steve - I haven't bought that "full auto" screw gun yet. I'm still a ways off from sheetrockin'. The electrical and HVAC needs to be roughed in still. And the live room wall needs to be framed up. There's also a little closet that for storage that I haven't started yet. That'll end up being part of the live room wall... and insulation needs to be placed, and... and... and...

There's SO much to be done! I spent the last day and a half hauling construction debris off to the dump! Five pick-up loads worth! It got to the point where I was moving junk from one room to another. And my yard, although hidden from any neighbors, had crap stacked up against the fence knee deep! That was REAL hard for me to deal with, because I have this "park-like" back yard. At least, I used to, before it turned into a construction site.

So, time to step back, clean up and re-group.

Re.: The walls. Fair enough.
Maybe I'm missing something though:
The staggered stud wall, with triple leaves gives an STC of 61. The double wall with triple leaves gives an STC of 63. ??
But you DO bring up a really valid point. And that is, Just HOW MUCH isolation do you need? For ANYONE contemplating ground-up studio construction, you have to answer this question before you even begin design. You could guess (not a good idea) or go with something that SEEMS reasonable (still not a real good idea) or, you could chart the noise on your site before you begin. Rent a dB meter, make sure its calibrated, and take measurements at regular intervals for a period of at least a couple of weeks. Graph the results, look for a high mean, and use that as a basis for your design.

The complexity of construction that I spoke of earlier... I forgot to mention that if your walls are not perpendicular to the trusses, which, unless they are exterior walls, they wont be, then you'll have a compound mitre at the top of the wall if you have a vaulted ceiling. Difficult to frame up unless you know what you're doing!

I JUST heard from my supplier. My front exterior door will be delivered tomorrow!!!!
Of course its a raw door and it'll have to be stained and well oiled, but, hey, its on its way!

Post by **John Sayers** » Wed Jun 11, 2003 1:06 pm

you sure have taken on a big project Michael. I bet you are fit!!!
It will be worth it - just keep dreaming of the day when you sit in your new control room.

:)

cheers
john

Michael Jones · Post by **Michael Jones** » Wed Jun 11, 2003 3:17 pm

Yeah, it is a big project. I've lost about 15 pounds since I started this! Gonna have to buy all new pants as the ones I have now are too big!
As long as SOMETHING happens everyday, I'm happy.

I REALLY want to hear that big ol' grand I have in the live room!
Which reminds me:
With your permission, I'd really like to use the "variable absorbers/diffusers" you had designed for Left Bank, but I can't find the pdf files you used to have posted.

I'm sure I can do a really good job building them; custom joinery is right up my father's alley as he's quite the woodworker.

Sen · Post by **Sen** » Wed Jun 11, 2003 7:14 pm

Thank you guys....
Steve, you understood what I meant, and thank you for your answer...
Michael, your works are looking really good...eventhough it sort of scared me a bit...It's like:
"How the hack do I get to that stage

?"
hopefully in the near future...

thanks

knightfly · Post by **knightfly** » Wed Jun 11, 2003 8:16 pm

Michael, agreed with just about everything you said. The comparisons I meant were with two layers of 5/8 rock each side, of either staggered stud or separate 2x4 wood stud frames. With insulation, the 2 layer staggered stud comes in at 54 dB, the separate frame at 63 dB . That's the 9 dB difference I was referring to.

Just for clarification (and so you don't scare me talking about triple leaf walls) I'm defining a LEAF as ALL the mass that is on one side of a frame whether there is one layer or three, a LAYER as one thickness of paneling, and an air gap as any area that doesn't have a hermetic seal interrupting it (insulation doesn't change an air gap into two air gaps)

I'd love to hear your piano in that room when it's done too - bet it'll be sweet... Steve

Michael Jones · Post by **Michael Jones** » Thu Jun 12, 2003 1:50 am

Ahhh... LEAF and LAYER.
I must get my nomenclature down correctly!
Now I understand. I think.

knightfly · Post by **knightfly** » Thu Jun 12, 2003 3:51 am

"Now I understand. I think. " -

Yeah, yeah, been there (and back, several times)

You'll get over it :=)

Sen · Post by **Sen** » Thu Jun 12, 2003 9:08 pm

knightfly wrote:2 layer staggered stud comes in at 54 dB, the separate frame at 63 dB .

Steve, how much air gap are we talking with this separate frame option (63db)? How much would a greater air gap improve the STC? I guess bigger gap = looser "air spring" = better STC.....
How much would additional insulation improve the STC? (let's say 2 layers instead of 1)
I know you can't get an accurate answer to this question, but would the two facts help a lot, and would sacrifice of the space be worth it?

thank you

Post by **John Sayers** » Fri Jun 13, 2003 10:58 am

Here it is Michael

http://johnlsayers.com/Studio/PDF%20Fil ... fusors.pdf

cheers
john

Michael Jones · Post by **Michael Jones** » Fri Jun 13, 2003 12:37 pm

Sen wrote:Thank you guys....
Steve, you understood what I meant, and thank you for your answer...
Michael, your works are looking really good...eventhough it sort of scared me a bit...It's like:
"How the hack do I get to that stage ?"
hopefully in the near future...

thanks

One board at a time buddy.
One board at a time......

Michael Jones · Post by **Michael Jones** » Fri Jun 13, 2003 12:39 pm

John Sayers wrote:Here it is Michael

http://johnlsayers.com/Studio/PDF Files/Variable_Bass_Absorbers-diffusors.pdf

cheers
john

That's the one!
Thank you, thank you, thank you!!!

I'll keep us all posted....