Wood or steel stud for studio walls ?

Well the subject line says it all. It is my understanding (i may be wrong) that for general soundproofing (200hz and up) a double wall desing made of steel stud would perform better than one with wood studs, due by flexion. But a wood stud design would perform better at lower frequency due by more rigidity. Am i right to think that ? I have seen STC charts of various wall desing but most of them i think are tested around 500hz or so. i can't seems to find info using the search feature about that issue. Thanks

Eric, this partially depends on the gauge of the steel and on the spacing of the studs. The "flex" factor of steel goes away if you have to use load-bearing, or "structural", gauge studs (like 20 gauge) - also, as soon as you go to double frames it's a moot point; this, because the main advantage of light gauge steel studs in a SINGLE framed wall is that they FLEX more than wood ones, thereby decoupling one wall panel from the opposite one. I've learned in the last couple of years that stiffness in a wall is NOT a good thing - ideally, you could have infinite mass separated by lots of air (or better, vacuum :wink: ) from a second infinite mass, and have both masses just floating - this would be the best you could get. Not being able to do that, the next best thing is a frame that allows the wallboard to be as floppy (floating) as possible; this is why 24" centers gives better isolation than 16" centers. It's also, in a way, why wider air gaps between masses is better (softer coupling "spring") . Yet another deciding factor - water retention. On the Building Sciences site (see the REFERENCE section) there is one paper that tells of a test house (around 2000 sq. ft. IIRC) built from steel framing and gypsum, the entire house could support a moisture content of around 5 gallons without causing damage; second house, wood frame, wood panels - 50 gallons. Third house, all masonry - 500 gallons!!! For this reason, I'm a bit nervous recommending steel framing unless the individual plans on a dehumidifier running in the space 24/7 except when actually USING the space. (with the humidistat set for 40% humidity, that is) HTH... Steve

Hi Steve. Still on the rigidity issue my guess is that, following the principle you stated, you would'nt use any stringer in a wood stud construction right ? Also i was still wondering if i would use RC channels at all, after your answer my guess is that i should use them, but only on one side of the double wall. Am i still right ? The moisture absorption factor being very low using metal studs is very surprising info to me. I always tought that steel stud would perform better under high moistures situations because they can't bend or twist under those conditions. But on the other hand, since moisture can't be absorbed by steel stud it is only normal that moisture will afect other component of the stucture (like plaster or gypsum). great info as always

Stringers, no; unless you're over 10 feet high, then code requires them for fire stops. RC - if you're using double frames (paneling only on one side of each frame) then no RC is needed, and it can even make things worse by adding another resonant frequency to the mix (therefore another frequency that gets thru the wall easier) - in fact, even using wide caps and plates and staggered studs the RC does little if anything; it's only needed where BOTH masses in a mass-air-mass wall would otherwise be rigidly connected to each other through the studs. Here's the Building Sciences paper http://www.buildingscience.com/resource ... ldings.pdf I find these are much faster if you right-click on the link and "save target as". It's not too huge, 6 pages in all... Steve

Thanks Steve you're my guiding light (':wink:')