What is the STC rating for a single sheet of 1/2 inch plywooc or mdf (or 3/4 in.

[Lenny]

I really can't find this information anywhere.  What I am doing is trying to build a small soundproof bedroom, just big enough for my bed.  I need to know this information, though, to decide between using MDF and plywood.

[Randy S]

OSB (oriented strand board) or Drywall are better products for sound control then what you mention in your post...

[Lenny]

OSB (oriented strand board) or Drywall are better products for sound control then what you mention in your post...

But does anyone know what the stc ratings are?  I mean, come one, you should always know the ratings, right.

[Randy S]

the problem with that would be the difference between field results and lab results....if you base your soundproofing project soley on material lab results I highly doubt you reach those numbers or even come close!...
There are basic principles that have to be in play in order to achieve high STC numbers...not just one sole material will do the job....
So if your looking for a specific STC rating on a specific product the manufacturer would have that information if they paid to have the "assembly" tested..and there lies the problem..all material is tested in a full assembly not by itself.
I personally would not stand behind the lab test results for plywood,mdf,osb or drywall...
However, drywall has a better mass value than MDF(better blocking sound) and OSB has more glue than plywood which means it would have a better dampening effect.

[johnbergstromslc]

MDF is about as dense as drywall which rates an STC of 28 for a 1/2" sheet.  But a single sheet of anything won't give you good soundproofing.  Build a real wall with one layer per side, preferably with insulation. 

Another consideration is cost - a sheet of 3/4" MDF is $35+, plywood/OSB is $20+ and drywall is 8-10 dollars.  You'll feel infinitely stupider making a cutting mistake with a $ 35 sheet of MDF than with drywall....