Now that I have the door installed and sealed up I decided to test the sound isolation. Wow am I disappointed
If you recall when the contractor installed the walls it caused the ceiling to be pushed up into the floor joists above all along the perimeter of the room. The ceiling is hanging from clips/channel except for the last 6" around the perimeter allowing for this mess to occur. Here are a few quick measurements I took inside the room using a radio shack dbc meter:
- 31 db inside the room and outside (quiet house and nobody making any noises)
- 60 db inside the room with someone walking bare feet on hardwood floor above
- 45 db inside the room with someone clanging dishes in kitchen above
- 40 db inside the room with someone slamming microwave door in kitchen above
- 31 db inside the room with high pitch stove timer beeping in kitchen above (can still hear it in theater room)
I have to try some measurements on sound leaving the room but I was initially playing music in the room at around 85db peaks and could only hear faint bass and mild vibration in hardwood floor above. I tried at 95db and things were not so quiet above. I wasn't testing with overly heavy bass tracks either so my initial impressions were not great.
At this point I haven't build my soffits yet so to try and 'adjust' for this I simply stuffed the 3x8" HVAC vents with towels. I think my biggest problem is the coupled ceiling perimeter. I also have an unfilled gap the width of the circular saw blade on one wall (as shown in one of my recent posts).
My next step is to run the circular saw all around the room to try to decouple the ceiling perimeter. Unless you guys can convince me that the isolation I'm getting now is close to what I should expect given my construction:
- dual stud walls, 5/8" OSB + GG + 5/8" DW, pink insulation and 5/8" DW on outside wall
- whisper clips and 5/8" OSB + GG + 5/8" DW, pink insulation in ceiling
Thoughts? Does anyone have hardwood floors above their room? Do you hear foot-fall noise? Dishes clanging above? Thx.