Which is better in a floated RC seiling...

I am ready to start installing my live room ceiling on resilient channel, but have the following question regarding the materials for the layers, and which would yield better stc results. Would it be better to use 2 layers of 5/8" sheet rock screwed to the R.C, or would it be better to use 2 layers, the first being "sound stop", and the other being 5/8" sheet rock? I want to achieve a higher stc rating because this studio is "for hire" and each group could be anything from a Gospel Quartet to full blown Metal. Thanks for the replies, Dr. J

I would have thought they are the same - 5/8" sheetrock here (australia) is called soundstop. To increase the STC I'd put a layer of celotex or MDF between the sheetrock. Sound doesn't like changing mediums. So I'd go like this: RC Channel 5/8" sheetrock 1/2" celotex or MDF 5/8" or 1/2" sheetrock. (dependent on budget) cheers john

I agree with John - I'd go with the Dietrich RC deluxe if you can find it, and if you use more layers put the RC closer together to compensate. http://www.dietrichindustries.com/bigdp ... sories.htm Steve