resilient channel vs. staggered studs

  • Thread starter Thread starter empire_of_one
  • Start date Start date
E

empire_of_one

New member
hello, i've been reading this forum for a few weeks but this is my first question here. I'm glad I found this forum, I will be redoing my basement in about a month and a half to soundproof and acoustically treat it. I am rebuilding my existing studio room (approx 27' x 11') and adding a 2nd control room (approx 10' x 11'). One wall of the CR will be shared with the studio.

I've researched at a few studio construction links:
http://www.saecollege.de/reference_material/
http://www.acoustics101.com
http://www.soundproofing.org

I am planning on using resilient channels on the studio and CR walls and ceilings. I was also planning on using staggered studs for the shared CR/studio wall. Many of the sites above have info on the benefits of these techniques, but don't describe using them both together. My question is, does using one of these techniques make the other redundant? Since the resilient channels and the staggered studs both are meant to prevent structural vibrations from passing through the studs to the other side of the wall, is there anything to be gained by using both techniques?
 
You might want to add this gem to your reading list.

http://www.bbc.co.uk/rd/pubs/reports/1995_06.html

"For both of the staggered stud partitions, it will be
necessary to consider whether the additional cost and
complexity of the partitions are justified in return for
the improvements in the sound insulations."

could prove useful in your situation.

Cheers
 
1 db?

Hi John, Rick Fitzpatrick here. Can you clarify something for me. I am trying to understand this db thing. Isn't 2db 10 times more than 1 db. And if it is, isn't it worth the extra work if it sound proofs 10 times more(1db) than without doing it. I'm probably looking at this all wrong, and if I am well "SHUT MY MOUTH!"lol Just trying to learn.
Fitz
 
Thanks, John. In other words.... yes it would be redundant.

Rick, dB are logarithmic and the figure I always remember is that an increase in 10dB is equal to 10 times as much sound energy. However, 3dB is equal to only twice as much energy. 1dB is about the minimum change in loudness the human ear can detect.
 
John Sayers said:
The actual difference is 1db

http://www.saecollege.de/reference_material/pages/STC Chart.htm

I don't see any benefit in doing both, plus it's more expensive. :)

cheers
John
Click to expand...

Actually, now that I've had the chance to check that link again, I don't think it answers my question. The chart shows the STC for resilient channels (47) and staggered studs (48), but it doesn't list the STC for a wall that has both resilient channels AND staggered studs. I thought you had meant that adding the resilient channels would only net a 1dB gain in sound reduction, but I must have misread you.

So what I really meant to ask was, if I have a wall with staggered studs, giving me an STC of 48, will adding resilient channels to that wall increase the STC of the wall by enough of a factor to make it worthwhile (say, by 5 to 10 dB)?
The wall between the CR and the studio is the only wall that I will be using staggered studs on (all the other walls are either being built against the outer stone foundation of my basement, or they will be adjacent to the non-studio area of the basement and will be single-studded), and the length of this wall is about 12 feet, so the expense of staggering the studs vs. normal studding isn't that great a difference, I just thought if there was nothing to be gained I might save myself some time and trouble. All interior walls of the CR and studio will have resilient channels however.
Thanks
 
the way I see it is that staggered studs AND resilient channels both use the same idea to reduce sound travelling through a structure. It the studs setup the drywall on one side doesn't transmit through to the other drywall, similarly with resilient channels that lift the second drywall off the stud. I suppose noone has done the figures for both because they are the same yet adding wouldn't achieve anything.

In your case Empire I would look at putting up a single stud wall with resilient channel and then putting up a reverse wall (i.e. drywall on the inside that has been built on the floor then stood up. This will give you three layers of drywall plus you will end up with a stud cavity to use for internal acoustic treatment.

We used that technique at Left Bank

cheers
john
 
what i have to work with

that sounds like a good idea, the only problem however is that there is a 8"x8" horizontal support beam that runs across the ceiling where the wall separating the CR and studio will be. Therefore, the two sides of the wall will need to be at least 8" apart. I had originally planned to put one set of staggered studs flush with the CR side of the beam, leave 4" dead space, and then frame the other side out from the beam.

OK basically I don't know what the best approach for framing this wall will be, given that there is this 8" beam to deal with. I don't want to give up too much space on either side, but especially on the CR side as room there is more limited. So I will try to post a diagram of my basement that shows the support beam and the location of the two rooms relative to it and hopefully that will give an idea what I'm talking about. The studio area is on the left side of the diagram, the black rectangle at the bottom right is the area where the CR will be, and the thick gray bar down the middle is the horizontal support beam that runs the length of the house. The small black squares are the two vertical support beams, and the large black square is the concrete support leading to the chimney from the furnace.
 

Attachments

  • studio_floorplan.webp
    studio_floorplan.webp
    12.6 KB · Views: 480
Adding RC over a staggered stud wall isn't going to have a 5-10 dB improvement in the STC rating. In fact, at STC 48 already, the staggered stud is tough to improve upon. You'd need a staggered stud wall and a RC wall to get just a 3dB improvement in STC (law of logarithms...you need to double or half the power to get a 3dB change).

What you should be more concerned with is the low frequency performance of your walls. STC is a convenient rating, but unfortunately it's set up much like A-weighting, with a heavy emphasis on higher frequencies such as those used in speech (e.g. 1-3 kHz). The low frequency performance of RC walls versus stud walls, and double walls is quite different. I suggest checking out the BBC's website for their journal papers regarding lightweight partitions. Interestingly enough, they found that most double wall constructions don't leave enough airspace between the walls to properly decouple...they acheived excellent low frequency isolation from two single faced walls (multiple layers of sheetrock), with a wide spacing and insulation between.

Cheers, and good luck!

Kris

PS: Your beam framing idea sound fine to me.
 
they acheived excellent low frequency isolation from two single faced walls (multiple layers of sheetrock), with a wide spacing and insulation between
Click to expand...

yes Kris, Tom Hidley in his studio walls uses double walls with three layers on the wall made up of a sandwich of fibreboard between two sheets of plasterboard.

Unfortunately that extent of construction is way beyond the budgets of most homewreckers :):)

cheers
John
 
You must log in or register to reply here.
Back
Top