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Discussion Starter #1
Well, I have the opportunity to help convert a garage into a private arcade/man-cave because one of my friends has been collecting vintage arcade machines for a while and has run out of space. The challenge is that the garage has an unfinished ceiling and the apartment above the garage has their bedrooms situated directly above the garage in question. Since THAT unit is paying most of the building's mortgage, if this private arcade is going to work the sound of the machines cannot escape upstairs.

Realistically, it won't be like a "real" arcade with 10+ machines making noise all at once. At most 1-2 units would be powered on at a time; given that these are traditional arcade machines, they aren't exactly quiet. I also don't anticipate have a bunch of people in this room (this is not an unlicensed gambling den)... just a few folks dropping by after work/evening to play a little.

So I looked online and found two popular ways to isolate the noise between floors. I know I need by SF code to use 5/8" drywall.
My initial thought was to put up insulation, then sound board (stuff looks like a sponge), and then 5/8" drywall. From experience I know this works but I'd like to see about doing something better.

However, there seem to be two other options which would help deaden the noise further. All work on the same premise of isolating the drywall from the ceiling.

Resilient Sound Clips & Hat Channels

Resilient One Legged Channels (cheaper b/c this system doesn't use any clips)

Green Glue Whisper Clips (Same principle as the Resilient Channels)

They also recommend multiple layers of drywall with Green Glue acoustic dampener between them.

Q: Since I know several of you folks are audio nerds and/or have construction experience, I wanted to see if any of you have had direct experience with sound deadening and how well it works. I'm not planning to finish the walls 100% (mudding/etc) but I do want to isolate the noise.

Thanks in advance.

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Now that I'm done with the soundproofing and drywall in the basement between the furnace and the home theater, I can offer some insights based on my experience and research.

The main issue is sound transmission from one side of the wall to the other via the walls themselves - sound transmission through the air cavities between the studs is surprisingly not as much of a concern - so the insulation in the wall doesn't make as much of a difference as most people would perceive. The drywall on one side acts like a microphone and intercepts the vibrations and transmits it to the drywall on the other side, which acts like a speaker, through the studs. To reduce that, you need to minimize the number of places where the walls directly attach to the studs. Double studded walls (exactly what they sound like - 2x4s next to each other with a small air gap between them, attached to 2x8 top and bottom plates) are best because one side of the wall is attached to one stud, which is only attached to the other side of the wall only at the top and bottom via the floor and ceiling plates. If you put the studs 24" on center, you reduce the number of attach points further. Where those aren't feasible there's staggered studs, with 24 or 16 on center studs. Those are 2x4s on a 2x6" top and bottom plate, with every other 2x4 aligned to the same wall. Again, as before, reducing the number of contact points between the walls.

Next up is vinyl sheeting between the studs and walls. The vinyl acts as a decoupling/isolating barrier between the studs and walls. Furthermore, it helps absorb the vibrations - think of what happens if you throw a ball at a sheet; same thing happens with sound waves.

Mineral wool is higher density than fiberglass - and there's even a high density version of mineral wool - which can be used in the air cavity to help absorb sound transmission through the air. Fiberglass insulation has an R value of about 3.5 R/in of thickness - standard mineral wool is about 4.5 R/in and high density mineral wool is about 5 R/in.

Resilient channel does the same thing staggered or double studded walls does - reduces the attach points of drywall to the studs. Another step is using insulated screw clips which have rubber grommets that connect the screw to the wall channel.

Thicker drywall adds mass. Two layers is all the better for that reason - and gives you the opportunity use "Green Glue" between those layers which is another way to decouple the two surfaces.

For an all-out solution, double studs 24" on center, vinyl sheeting, high density mineral wool, resilient channel with isolation clips, and 2x 5/8" sheets of drywall with green glue between them will be about as good as it gets.

So anyway, a lot of those are really expensive and can't be done implemented in existing construction without impractical major renovations - the stud configuration for instance.

What I did in the basement was a bit of a cherry-picked hybrid of these items, given my budget and priorities. I chose a double studded wall (although 16" on center 2x3s instead of 24" on center 2x4s to reduce wall thickness) with mineral wool and vinyl sheeting. There is an STC calculator here which you can play with to experiment with some combinations. (not sure why but the STC is currently being displayed as currency, lol)

I currently have 3" of mineral wool in the wall (not the full 6" of wall thickness) and I have nothing on the furnace side (yet) - vinyl sheeting and 1/2" drywall on the theater side. At the moment when the furnace kicks on, I can hear a low rumble and the sound of the furnace/rushing air coming out of the air return vent is louder than the sound of the furnace. I'm planning to add a second layer of vinyl to the furnace side of the wall - I may or may not add another layer of drywall but I'm pretty content with the results given the "minimal" additional hassle and expense involved. The vinyl sheeting is about $1.50/sq. ft depending on where you source it.
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Video games are mostly higher frequencies, so they are easier to attenuate than bass.

Hanging a dense ceiling composed of multiple layers of office-type drop ceiling panels with insulation between them might be enough.

And hanging artwork on the walls made of rug type material is good for killing higher frequency sound.

The techniques you guys listed are pretty much the way to go; double walls, offset studs, and rockwool works wonders.

These guy's products aren't cheap, but they Are effective.

I'm thinking seriously about building an all in one Arcade style standup ot tabletop game, and run it off one of my old PCs and MAME.

I play a lot of the old games on PC now; it would be nice to have a dedicated standup machine, or one of the two sided tabletops.

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Where is this arcade going to be ?? Hit me up Gunn, I am currently working at Garfield Elementary School on Filbert street near Telegraph hill / Coit Tower . :cool:

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Discussion Starter #5
So I did a bunch of research and found a pretty good video on what I'm trying to accomplish.
  • His basic statement but since there is some exposed ductwork between the garage and the upstairs living space, sound WILL transfer. As long as I can numb it down significantly, I dont' believe this will be an issue. The exact situation he mentioned was a home theater running full tilt while another group sits around having wine upstairs; that's not my situation and not possible.
  • He basically advocates for insulation, two layers of drywall sandwiching green glue.
  • He also argues that mineral wool (a popular recommendation because of its higher density) and fire resistance is actually NOT necessary since the double layers of wall will add more sound deadening and fireproofing than the mineral wool will do.
  • As far as hat channels, furring channels, quiet clips or whisper clips are concerned, they would make a difference but I'm not sold on the extra cost.

Here are more details on my specific situation
  • This garage is approx 21' x 28.5'. Very nearly 600sq ft. Some of the floor space is taken up by the two furnaces (no A/C because SF) and two hot water heaters. There is new ducting (new because I just removed the old asbestos wrapped stuff) that is wrapped in bubble wrap. No vents/registers are in the garage BUT sound could carry through the tubes (see pics) into the upstairs floor.
  • The 2" thick joists are solid wood spaced 14" apart. There are 15 "channels" between joists so The floors upstairs are hardwood so sound will transfer through.
  • The sound sources would be old school arcade machines. Not much bass here. No plans to add a home theater although I might put an LCD tv and my steering setup over here.
  • Floor is cement. I'm not finishing out this room. It's a garage.

My current estimates (outside of labor) are that i will spend:
$300 for fiberglass or $372 for mineral wool (probably opt for mineral wool). Aprox 430ft x 15"
$428 for 38 sheets of 5/8" drywall
$522 for green glue adhesive (36 tubes)
$48 for green glue sealant (4 tubes) -
= $1370 + labor

1) Mass Loaded Vinyl aka dynamat: I haven't found it for $1.30sqft yet (shipping kills because 100sqft = 100LB) but even at that price we are talking about ~$800.
- From a performance standpoint, it seems like this is good for cutting down bass and lower notes. That's not really my problem.

2) Resilient Channels or some kind of channel suspension to suspend the drywall (up to two 5/8" sheets).
NOTE: i already confirmed that the one Legged resilient channels won't even hold up a single 5/8" sheet based on weight so i have to go with a clip+channel system. The LB3 clips seem to allow for a lower profile mounting so I won't loose too much height to the new ceiling.
  • yes, I get the idea on why this drywall Isolation is good but the estimates are I would need 360' of furring/hat channels and 100 clips. I haven't found a local source for furring/hat channels yet but just using online options, the clips+channels would add another $1-1.2K to the cost of this project as well as added labor.
  • Considering that this would 2x the expense for this game room/man cave, I'm not sure it's worth it.
Q: What do you folks think?

3) As a further way to cheapen the install, instead of using GreenGlue between two layers of drywall, I could buy this stuff and eliminate the need for $522 of the Green Glue deadener stuff and half of the drywall. I would still use the Green Glue sealant. I need to confirm if this would be OK with code (I think I need a 5/8" minimum between garage and living space) but it would SAVE me more $$$.
Q: What do you think? would I be cheapening out too much here?

4) Wall off the HVAC system? Take a look at the pics, I don't think this would be terribly viable (AND a giant PITA for maintenance).
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