[SteveRB]

hello,

I am interested in decreasing sound transmission through the partition wall between my apartment and my neighbour. I was considering covering the entire wall with 2" OC703 and then covering the wall with heavy felt material. The wall in question is about 25' long. My hifi is in this room and I would like to disturb my neighbour less than I currently do.

Does this seem like something that would help, or is it a lot of work for little reward?

I was hoping to consider the final installation just like any normal wall, hang a couple pictures on it... I was also planning on hanging several diffusors to ensure that the room does not end up to 'dead' sounding.

THoughts?

[gregfisk]

If you read up on soundproofing a wall a couple of options come up. One is using a green glue on the existing sheet rock and then putting another layer of sheet rock on top.

The other way which I'm sure is much better and is what I did in my new audio building is hat channel. Noise is vibration and is transferred from one side of the wall to the other. What hat channel does is separates the sheet rock from the wall which helps stop the vibration from transferring to the other side. I don't know whether it works as well between two sheets of rock. It is usually used on the studs before the sheet rock goes on but it seems like it would still work.

Some people use hat channel and then two layers of sheet rock on top of that and some also use the green glue between those two layers.

[ctviggen]

It would be relatively useless.  The main things that work to reduce sound transmission are mass and a break (decoupling) of some sort.  Mass is usually created by heavy drywall (so called fire rated drywall is about the heaviest), even several layers, one or both sides of the wall.  The break is caused by preventing one side of the wall from touching the other side.  For instance, building two sets of 2x4s (each one a part of a "wall") that are spaced apart by a small amount will create a very good wall.  The way walls typically work is the drywall is screwed to one side of the stud and the other side of the stud is screwed to another layer of drywall.  There's no break, so sound easily passes from drywall to stud to drywall. 

Here's one website with more info:

http://www.avsforum.com/forum/19-dedicated-theater-design-construction/1509173-soundproofing-master-thread.html

[mresseguie]

Steve,

Do you own your apartment, or is it a rental? [I ask to determine if you can actually physically alter the wall vs making a temporary change.]

There are heavy duty 'sheets/curtains' that help block transmission of sound, but I've never actually used them, so I don't know how effective they are. Let me see if I can find the link....Got it:  https://www.vocalboothtogo.com/product-category/acoustic-sound-blankets-for-sound-absorption-producers-choice/

Good luck!

[jk@home]

Safe and Sound insulation works great for this. But if you rent the joint you won't be able to tear into the walls and install it. Maybe you could build a second wall (not permanent) in front of it , with a small air gap between the two.  At least the S&S is cheaper than the OC703 stuff, and can be found at the local big box lumber store.

http://www.homedepot.com/p/Roxul-Safe-n-Sound-3-in-x-15-1-4-in-x-47-in-Soundproofing-Stone-Wool-Insulation-12-Roll-RXSS31525/202531875

[gregfisk]

Steve,

Do you own your apartment, or is it a rental? [I ask to determine if you can actually physically alter the wall vs making a temporary change.]

There are heavy duty 'sheets/curtains' that help block transmission of sound, but I've never actually used them, so I don't know how effective they are. Let me see if I can find the link....Got it:  https://www.vocalboothtogo.com/product-category/acoustic-sound-blankets-for-sound-absorption-producers-choice/

Good luck!

I was wondering about this as well Michael, if it's a rental I don't think adding hat channel, sheet rock or another wall inside the original is going to fly. I did do both in my new room, hat channel on two walls and a double wall on one end. The other end has an additional storage room so I just insulated the inside and the outside wall. The order of sound proofing from least to best is hat channel, double wall and then storage room. I don't know anything about curtains but that sounds like a good idea for a rental depending on how well it works.

Good Luck Steve.

[rajacat]

This company's site is very informative. Here's some curtain info.
http://www.soundproofing.org/infopages/curtains.htm

[JLM]

The stated STC (sound transmission coefficient) of their curtain is about half of a regular interior (uninsulated) wall and require double sided tape to make the necessary seal (could rip paint off).  And they are black/grey.

Have you considered headphones for your rowdy audio moments?

[SteveRB]

Thanks you for the information. I do own the unit, but the cost and trouble of re building the wall is prohibitive. The current configuration is a staggered stud wall with fibreglass insulation, single sheet of drywall per side.

It looks like as air gap and massive surface material are the best bet to help limit sound transmission to my neighbour. I can install a wooden J-Rail that will give about a 1" airgap and 'hang' 3/4" sheets of heavy ply across the wall.

[rajacat]

Why not use 5/8" sheet rock instead? It has more mass. Just tape and mud the seams, caulk the corners and paint. If you can butt the tapered seams it will ease the task of making them invisible. Taping the corners, IMO, makes the job much more difficult and the goal is soundproofing not strength.

[SteveRB]

Why not use 5/8" sheet rock instead?

because this place looks cool:
https://parttimeaudiophile.com/2015/08/28/pdx-hifi/

[WGH]

What is the wall sitting on? If it can handle the weight then 4" cinder block with a 4" space behind it would be ideal. Cover the block with drywall and play music as loud as you want. What you want is a 55 dB transmission loss.




This is not a new field of study, there is a ton of info available by Googling "sound transmission loss materials".

Here is one site that has lists of the effects of wall types measured as a Transmission Loss (TL)
http://engineeronadisk.com/notes_mechanic/sounda9.html

[SteveRB]

Interesting. I'm not sure I have room for mason work. But I love the idea.

With the chart, how does using two or more of the materials sum together? do two 30's make a 60, a 40, a 33.33...?

[JLM]

Adding drywall (and ideally with furring strips behind) or block will add wall depth thus requiring furring out around windows/doors, floor molding, flooring, etc.  Yes, the values shown are additive, but depend on workmanship (details are everything when it comes to insulation).

An insulated staggered stud wall should be a very effective, yet practical, sound barrier (have successfully used a couple of times).  Must be other leaks.  Does the wall extend to the deck/roof above?  Is there shared ductwork?  Are the electrical plugs or light fixtures fully insulated in the wall/ceiling spaces behind?  Do you and neighbor share nearby doors and what are they like (weather sealed, solid core/insulated)? 

How loud and when do you listen?