Soundproof Listening Room

[Patrick Bateman]

According to Gedde's home theater book there's supposed to be a "channel" in a sound proof wall. I don't understand what the channel is there for. Has anyone figured this out?

I know a thing or two about horns, but I'm new to soundproof rooms.

I understand the concept of having two isolated walls, with staggered studs so that the two walls don't actually touch. But what's the channel there for?

The studs are attached to the wall right?

home theater book i just read

[Chip-Audiophile]

Not really sure what the "channel" would be. My guess that it is just the space between the two stud walls.

I am an Architect and have worked on a number of designs with acoustic engineers that have involved room acoustics and sound proofing. Basically the best scenario was to have a central wall of high mass [precast / off form concrete wall say 50 - 100mm thick or concrete filled block wall]. This limits the transmition of lower frequencies. Either side of this you build say a 90 x 45mm stud wall that is disconnected from the concrete wall. This stud wall is then infilled with acoustic insulation. Line the stud wall with 2 - 3 layers of plasterboard, preferably fire rated [it's denser] or altenatively a compressed cement sheet has more density [the denser the material the better]. The ceiling and floors also need to be treated in a similar way as the room will only be as "sound proofed" as your weakest link. Everything needs to be isolated from room to room. This can be done via suspended ceilings or resiliant rubber mounts so that you fix the wallboard via an isolated acoustic mount. This will limit sound transmission to the building structure and hence stop it from traveling to other areas. The engineer even taked about having a separate concrete slab for the sound proof roof. The room also needs to also be air tight so caulk all joints between wall board, door + window seals etc. Room treatments can also be used to break up standing waves and improve the performance.

Staggered studs is just another way to go but is not quite as efficient and is basically just a way of making the wall thinner because as you can tell the walls start to get quite thick!

Check out "The Red Book" in the link below. It shows a large number of possible wall constructions and their Rw rating [sound proofness]. You will get the idea that more is better...

http://www.gyprock.com.au/downloads/...eIteration=144

[TerryO]

The channel is a metal extrusion (often "Z" shaped) that decouples the drywall from the studs. It's usually installed horizontally on 16 inch centers and then 1 or 2 additional layers of drywall are then screwed onto it. I understand that applying "Green Glue" to laminate the drywall is the way to go, at least according to the pros.

HTH's,
TerryO

[doorman]

Having spent time in, and building with the above "Z" bar system, it really does help w/soundproofing, but the low freq. still find their way through.
Don

[MartinQ]

He is probably talking about resilient channel.
http://www.greengluecompany.com/gree...entChannel.php


Apparently a better system to use involves RSIC clips instead of the basic channel as well as the Green Glue (or some other effective constrained layer damping).
http://www.pac-intl.com/products.html
http://www.acousticalsurfaces.com/rs...risc_clips.htm

[ACCUPROAV]

I HAVE USED THE CAVITY TO FURTHER INSULATE W FIBERGLASS .

ALSO HAVE USED INSULATING RUBBER UNDER THE DRYWALL FOR LESS TRANSFER OF VIBRATION. THE MORE ISOLATED THE SURFACES ARE INCLUDING THE FLOOR AND CEILING STUDS THE BETTER.

[MartinQ]

Originally posted by ACCUPROAV
I HAVE USED THE CAVITY TO FURTHER INSULATE W FIBERGLASS .

ALSO HAVE USED INSULATING RUBBER UNDER THE DRYWALL FOR LESS TRANSFER OF VIBRATION. THE MORE ISOLATED THE SURFACES ARE INCLUDING THE FLOOR AND CEILING STUDS THE BETTER.

PLEASE TONE DOWN WITH THE CAPPS (capital letters), please and thanks. We can all hear you just fine.

[cuibono]

I've done some soundproofing for home recording. To me, the number 1 thing is air sealing the room - any leak, and all sounds go right through. Similarly, any windows have to be boarded up - sound goes right through them. The special construction of walls/ceilings is for low frequencies, which seems like less of a problem to me - its just a fraction of all the frequencies in sound. Particularly, if your neighbors are in a physically separate building and you've sealed the room and windows, even if there are very loud drums in your room, inside their house it would be barely perceptible. If, on the other hand, your wife doesn't want to hear your sub, or you're in an apartment building, thats a lot more difficult. But without an air seal, all those special walls would be useless.

The last room I soundproofed (sealing doors and windows), we would play extremely loud (drums, guitars), and outdoors, standing next to the room, it was barely noticeable. I'm sure my neighbors couldn't hear it inside their houses.

[bartoneblaze]

channels are use to reduce effect of noise and to dampen the sound waves,so resilient metal channels can be inserted between one of the drywall walls The resilient channels act as shock absorbers, greatly reducing vibrations coming from either side of the wall from passing through the wall. Absorbent mat is used inside the wall to cushion the channel/drywall and to provide an absorbent compartment to trap sound waves.

[DrDyna]

Originally Posted by MartinQ

PLEASE TONE DOWN WITH THE CAPPS (capital letters), please and thanks. We can all hear you just fine.

Sir, I am very insulted by the size of your text! Do you know that occupied 5 millimeters of screen space instead of just 3?

The nerve!