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Finishing a media/theater room in the basement. Have a quick question regarding reducing sound from basement to upstairs. I will have about 8 recessed lights in the ceiling. I know these allow a lot of sound through and you can’t insulate them due to fire hazard. I was planning to install double Layer of Type X 5/8 drywall separated by GG and placing some R13 in the spaces between joists in ceiling.

Will this be effective or am I wasting money due to the recessed lights? I am not looking for recording studio silence, just something to reduce noise upstairs so it is not so obnoxious for my wife when I am cranking it.

I do not have little kids, this is to make it more acceptable for my wife, without blowing the budget.
 

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I don’t have an answer to your question, but am curious about soundproofing as it’s something i had not considered for my build - how expensive adding another layer of drywall? I’m curious if it’s worth asking the builder to price it out. Like you, it’s just me and my wife, but I’m wondering if the double drywall will do enough good to justify the cost or if I should just use headphones at night


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The drywall cost is negligible, about $2 per sheet. Green glue is $200 per case of 12. You are supposed to use two per sheet, so that depends on the size of room. Labor is $0 for me. My contractor said he would add it as part of the job, but even if charged, hanging 10 extra sheets of drywall can be much. Total cost less than $1K, with GG being most of it.
 

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Will this be effective or am I wasting money due to the recessed lights?
This will decrease your effective STC number/$ ratio drastically, yes.

...Reduce noise upstairs so it is not so obnoxious for my wife when I am cranking it...No kids...more acceptable for my wife, without blowing the budget.
Short Answer:
Type in backer boxes and see what that search brings you (This will give you the cheapest solution and still give you 52 STC). This should be done for every penetration into the outer DW shell of the theater.

Expanded Answer:
You will likely want to create 8 small backer boxes of MDF with 5/8" DW with GG in between and sealed with acoustic caulking where the electricity comes in and around the seams.

I know it seems like a lot of work but it is worth it.

If you really wanted to eliminate sound from upstairs to downstairs and vice versa you would do:

GG/DW/GG/DW in-between the joists (eliminate foot fall noise from walking above), then pink fluffy OC703 or something similar (eliminate resonance), then clips and hat channel (to decouple) (see https://www.soundproofingcompany.com) backer boxes to help with holes in the structure, DW/GG/DW (all 5/8" DW) DW for mass and GG for Dampening. (Buy GG in 5 Gal. buckets)

The higher STC the better:
No DW etc... between studs goes from 76 to 66 STC
No Clips and Channel will go from 66 to 52 STC
No backer boxes will decrease the number even more.

Rabbit hole provided: FWIW IMHO

Aaron
 

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home made ones, good boxes are a single layer of 3/4 MDF, best are laminated boxes with 3/4 MDF lined with another layer of drywall or cement backer board with an dampening agent between layers (Green Glue). Pics attached. There are some commercially available boxes, I've used them back when they were 1/2 the current price. https://isostore.com/quietbox-recessed-light-soundproofing.html
 

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Will this be effective or am I wasting money due to the recessed lights?
The higher STC the better:
No DW etc... between studs goes from 76 to 66 STC

Rabbit hole provided: FWIW IMHO

Aaron
Are you saying that in a wall, you can gain 10 STC if instead of installing drywall (or clips, channel DD+GG) directly on the wall as normal, drywall the inside of the stud wall, and the small 4 inches of width of each 2x4?
 

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home made ones, good boxes are a single layer of 3/4 MDF, best are laminated boxes with 3/4 MDF lined with another layer of drywall or cement backer board with an dampening agent between layers (Green Glue). Pics attached. There are some commercially available boxes, I've used them back when they were 1/2 the current price. https://isostore.com/quietbox-recessed-light-soundproofing.html
BIG,

In your last photo with the completed backer box, how do you fill the gap between the backer box and the drywall? Looks like the backer box doesn't line up with the bottom edge of the hat channel. Is that filled with cut drywall or something else?
 

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BIG,

In your last photo with the completed backer box, how do you fill the gap between the backer box and the drywall? Looks like the backer box doesn't line up with the bottom edge of the hat channel. Is that filled with cut drywall or something else?
The backer box IS on the same plane as the hat channel. I've done mine the same way and it offers excellent results. Just be sure to put a nice thick bead of caulk like Silentseal on the landing of the backer box before you mount the sheet of drywall. That will give a nice seal to the back of the drywall.
 

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Yes, the lip of the backer box is flush with the bottom edge of the channel, as mentioned use a thick bead of acoustical caulk.


BIG, do you recommend the same sealing process for backer boxes for atmos speakers?


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LED Light Strips

I put high discharge LED strips in recessed channels in my soffits. Added extra drywall and green glue to keep it at double drywall thickness. But, the channels can also be surface mounted.
 

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