John Sayers' Recording Studio Design Forum Archive

hellohellohello......we are in the process of constructing a live room......not a lot of cash to spend.......we are using resilient channel and a layer of 1/2" plus a layer of 5/8 on the inside walls.......have heard various debates about resilient channel......some have said that not using sonopan in conjunction with the sheetrock basically nullifies the efficacy of the RC......is this true......are we alright just using the double layer of sheetrock without the sonopan?....... and what exactly would the difference be if we were to add that layer of sonopan?........(STC?).......thanks for yr. time.....

It is linked throughout the forum. Read NRC BRN-217 and if your up to it IR-761.

There is also a topic RC LF TL dealing specifically with RC.

Andre

I found it kind of interesting that sonopan seems to be a Canadian oddity, and yet the Canadian IR-761 document, which chronicles tests of 350 different wall constructions, does not mention the word "sonopan" even ONCE. Whereas the same document mentions the word "resilient" 261 times, and the word "gypsum" 1972 times.

Am I the only one that finds this a good enough recommendation AGAINST paying more for less??!?

Does anyone know if the Canadians are working on a 350-wall test using only sonopan?

Just curious... Steve

Hank, sorry if that sounded a bit churlish - I hear so many people getting conned into spending more money for less that sometimes it just pisses me off - not at you, at the people who take advantage of the complexity of this field by screwing people out of their hard-earned money.

You can take this to the bank - gypsum wallboard, in any area that's not too wet to use it, is the absolute best bang for buck when building sound proof walls. Period. Not mass-loaded vinyl, not sonopan, not "sound" board, not homosote, not MDF, or particle board, GYPSUM.

The only exception to this is if you're in an area where certain masonry products are really cheap, and gypsum has to be shipped in at extra expense.

What makes sound walls quiet is MASS - two separate centers of it, separated by an air space filled with open celled insulation. The more mass, the better. Slightly different mass in each center of mass is better. Wider air gap is better. Adding yet another air gap and another mass is WORSE.

You asked for STC rating of half of your wall system - while that's doable, I would think you'd rather know the entire story. To do that, we'd need the rest of your construction details - what's the ENTIRE wall made of, from outside to in, layer by layer, in detail? If you post that, I'd be glad to calculate the rough STC for you including separate Transmission Losses down to 50 hZ, and explain how I got those figures.

As for Resilient Channel, the use of it usually makes mid-range isolation better by up to 6-7 dB IF, IF, your wall uses a single 2x4 stud frame for both leaves (centers of mass) - RC does NOTHING for the low frequency TL of a wall; TL at lower frequencies may even be BETTER by a dB or two by NOT using RC, if the wall uses double frames with wallboard ONLY on the outer side of each frame.

Again, I wasn't trying to be grumpy with anyone here, just "soap boxing" on so-called "magic bullets"... Steve

I found it kind of interesting that sonopan seems to be a Canadian oddity, and yet the Canadian IR-761 document, which chronicles tests of 350 different wall constructions, does not mention the word "sonopan" even ONCE. Whereas the same document mentions the word "resilient" 261 times, and the word "gypsum" 1972 times.

I had a nice chuckle reading this. Sonopan is a trademark adjective, like gyproc or kleenex. NRC uses generic descriptors as much as possible.

From what I can gather, sonopan is one company's fibreboard.

Andre

Yeah, I followed up on this almost a year ago and after cruising their site and seeing specs and recommendations, I came to about the same conclusions... Steve

Sounds liks sonopan is the canadian version of homasote, another brand name that seems to be talked about more than it deserves.

The thing that will really wreck a RC installation is bad construction practice, failing to caulk gaps or screwing too far and having the screw touch the stud. Rather than the sonopan If you wanted to spend more on something I would look into those cushioned RC mounting brackets. They will increase the decoupling and make it harder to screw through to the stud.

No arguments from me on any of that...