The grommets keep the resilient away from the stud. The metal to metal is via the head of the screw and resilient. I suppose you could have a grommet on both sides sandwiching the resilient for the ultimate as well as a grommet in front of the screw when at the ceiling.
I have not as yet gone that far since my level of requirement is strictly residential so no serious technical specs involved. It's impossible to predict an outcome accurately due to the particular circumstances/structure in question. I have been confronted with scenarios where a single continual townhouse sub floor is divided into separate units by concrete walls formed through and around the wood structure. This allows the entire wood structure to act as a speaker cone or diaphragm where everything right up into mid range frequencies are clearly audible everywhere. Impossible to fix, a serious design flaw.
OTOH, I've had such success as to have children screaming and jumping on the floor above and only faintly hearing it as though the windows in the house in question and the next door neighbor's windows were open and the sound was coming from the next door neighbor's separate house.
Every circumstance is unique. You never get the same result twice. It's the luck of the draw to a significant degree. I've had to build a separate wall 12" thick/12' high/100' long in front of an existing wall in an aerobics studio separating a doctor's clinic to quiet things down; done incrementally until it was satisfactory. I've also had very disappointing results using Quietrock attempting to quiet down the separation of another clinic and dog grooming facility. Next step there would have been to also build a separate wall in front, reducing the usable space which they did not opt for.
A guy with his drum kit in the basement driving his wife crazy because it literally shook the entire house! I politely said to her after a demonstration by her husband once my feet were numb from standing on her kitchen floor listening to the music, "I'm sorry ma'am, I can't help you".
I have not as yet gone that far since my level of requirement is strictly residential so no serious technical specs involved. It's impossible to predict an outcome accurately due to the particular circumstances/structure in question. I have been confronted with scenarios where a single continual townhouse sub floor is divided into separate units by concrete walls formed through and around the wood structure. This allows the entire wood structure to act as a speaker cone or diaphragm where everything right up into mid range frequencies are clearly audible everywhere. Impossible to fix, a serious design flaw.
OTOH, I've had such success as to have children screaming and jumping on the floor above and only faintly hearing it as though the windows in the house in question and the next door neighbor's windows were open and the sound was coming from the next door neighbor's separate house.
Every circumstance is unique. You never get the same result twice. It's the luck of the draw to a significant degree. I've had to build a separate wall 12" thick/12' high/100' long in front of an existing wall in an aerobics studio separating a doctor's clinic to quiet things down; done incrementally until it was satisfactory. I've also had very disappointing results using Quietrock attempting to quiet down the separation of another clinic and dog grooming facility. Next step there would have been to also build a separate wall in front, reducing the usable space which they did not opt for.
A guy with his drum kit in the basement driving his wife crazy because it literally shook the entire house! I politely said to her after a demonstration by her husband once my feet were numb from standing on her kitchen floor listening to the music, "I'm sorry ma'am, I can't help you".
We used hat channel w/soundproofing clips. Install the clips on the stud .... snap in the hat channel and go. What is drywall furring channel or hat channel?
This used to bug me too ... untill I started breaking joint off the stud ... in between. Used a infilled plywood backer set back about an 1/8" off the stud face between the framing. Better tape joint, too.
"Butt Board". About 5" wide, 48" or 54" long particle board 3/8" thick, 1/16" taper to the center from both sides. Allows a recessed butt joint resulting in a flush finish, expensive, though. I just use Rhino Board floor protector cardboard I cut into 1.5" strips placed one stud back from the designated butt on either side. Same result, however may require more than one layer depending on the crown of stud or joist. A 1.5 " landing is not an issue to a highly skilled craftsman.
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Canadian NRC has detailed engineering guidelines for walls with different STC ratings. I have them downloaded somewhere but I am sure you can find them online. I remember something like using metal studs and resilient channels mass loaded with doubled drywall where the second layer is only glued (not to bypass isolation by screws) had a superb rating. just to point to NRC here is a link to a short paper:
https://nrc-publications.canada.ca/eng/view/ft/?id=7c9971a9-227a-433a-8c06-cd00af83a236
https://nrc-publications.canada.ca/eng/view/ft/?id=7c9971a9-227a-433a-8c06-cd00af83a236
If it's an interior wall (2x4 plates) use offset 2x3 studs.
Exterior wall (2x6 plates) use offset 2x4 studs.
These screws are not likely to offer what they suggest. Just like green glue, strips of rubber or any other damping solution. As mentioned by others, you really have to properly decouple the modes of transmission, at least on the large central parts of the panels. Fastening the drywall to the top and bottom plates is not a concern as they are fastened to the base material, often concrete.
I am of course speaking of isolation from one area to the next. Not with a sound absorbing panel so I may be off base.
Exterior wall (2x6 plates) use offset 2x4 studs.
These screws are not likely to offer what they suggest. Just like green glue, strips of rubber or any other damping solution. As mentioned by others, you really have to properly decouple the modes of transmission, at least on the large central parts of the panels. Fastening the drywall to the top and bottom plates is not a concern as they are fastened to the base material, often concrete.
I am of course speaking of isolation from one area to the next. Not with a sound absorbing panel so I may be off base.
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Depends on who framed it up.A 1.5 " landing is not an issue to a highly skilled craftsman.
It's only ever "almost" level, plumb, or square. I always take two measurements... but not twice each.Depends on who framed it up.