Mixed Messages - Sound Proofing and Open-Cell Foam (1 Viewer)

[CyFactor]

I've read two different schools of thought now that open-cell spray foam is either 50 STC or 39-40 STC depending on who's doing the reporting. Now I am beginning to wonder if my reliance on open-cell foam was a mistake. My contractor said it would be superior to batting, and for thermal control I have no doubt that is true. I just watched the video in the beginner's section about blown-in cellulose. Did I make mistake?

I think where I have an advantage in this setup is there are no adjoining rooms on any wall of the theater room except the hallway. All other walls have plenty of airspace between them and the main living area. The main concern would be the rooms below. During construction, even after they sprayed the floor, I would swear I could hear a pin drop on the floor above me because the vibration transmits down the wood. I'm beginning to think I should have used joist isolators. Short of ripping up the floor, that's no longer an option at this point.

So, mistakes were made. I should have used double-wall or at least double 5/8th gypsum, no? I do plan to use a sound dampening carpet padding at least. That should help isolate the floor a bit more, and I am also considering putting the front channel speakers on pedestals.

So what's the real deal with open-cell foam versus blown cellulose versus batting?

Thanks!

EDIT: Incidentally, this was one of the videos that started sending me more positive vibes. When he taps the floor at 2:05, it is a night and day difference:




--Vince

 

[CyFactor]

Anyone? Maybe the banana band can inspire you.

 

[DavidJ]

I don’t have an answer but am curious to see what others say.

 

[CyFactor]

I don’t have an answer but am curious to see what others say.

Well, I suppose I'll just have to measure it. There must not be too many folks in here who have done it yet. I'm waiting for the doors to the attic to get installed first, though. Tomorrow, the door for the HVAC area gets installed, and either Saturday or Monday the 1/2 door to the remaining attic space gets installed. I'll stick a battery-operated boom box in the attic space, measure it with my SPL meter, and then see how much sound travels through the wall and report back.

Side note, I'm also going to need some heavy soundproofing pad on the floor before I lay carpet. I've been watching a lot of videos lately, and there are some pretty impressive products out there. They textured the walls yesterday, and when they were mixing the mud above my head it sounded like the ceiling was going to come down on top of me (the main room is right above my office). So far, I'm not too impressed with open-cell spray foam.