Help sourcing RC2 resilient channel

[DC in ATX]

Hey, TB recording experts.

I finally have a dedicated music/listening room!

(Seller’s staging.)

Now, I just need to come up with a marriage-friendly way of using it. One initiative in this effort is doing some strategic sound isolation. Talking to an audio engineer friend of mine, we came up with a down-and-dirty scheme using RC2 resilient hat channel and 5/8" drywall (and later some in-room mitigation, such as bass traps).

I'm guessing someone here has been down this road before. If so:

Where did you source your RC2 resilient channel?

Our new old house is in Chicago. Maybe someone has it on a shelf here. I'm guessing I'll need to special order some. It's not a giant room (192 SF).

 

[silky smoove]

I have many thoughts on this. You can read through my studio build thread to see channel being used, although not RC2. Also, buy a copy of the latest edition of Rod Gervais' book and read through it thoroughly, if not multiple times before you begin. Also, be sure and start a build thread on the John L Sayers forum for advice from a larger pool of experts than you'll find here on TB.

Questions:

• Why are you considering RC2? Hat channel isn't that much more expensive and offers better performance.
• Is your plan to use channel mounted directly to the studs? If so, consider Whisper Clips or any of their less expensive but less well-performing competitors. It will increase performance considerably, although it will eat up more of your floor space.
• You describe "strategic" sound isolation. Unless you're building a booth the isolation can't be strategic and also be effective. I'd either plan on gutting the room or building a separate iso booth within the room.
• You describe RC2 and 5/8" drywall. If you mount RC2 to the studs and then put up a single layer of 5/8" drywall you'll get some isolation, but don't expect miracles. A drumkit will blow right through that. Do you have room for multiple layers of drywall? If so, and isolation is a concern, double-up the drywall and put Green Glue in between the layers.
• There are many retailers that sell this stuff. Trademark Soundproofing out of New York is where I bought all of my hat channel, Whisper Clips, putty pads for light fixtures and outlets, Green Glue damping compound and Green Glue sealant. They were great to work with.
• If your goal is to do the whole room and the iso booth idea isn't appealing, how are you going to deal with the door, light fixtures, electrical outlets and those curious soffit/chase areas that poke out of the walls at an angle? Further, if you want to do the entire room, how are you dealing with HVAC and its sound isolation?

 

[DC in ATX]

I have many thoughts on this. You can read through my studio build thread to see channel being used, although not RC2. Also, buy a copy of the latest edition of Rod Gervais' book and read through it thoroughly, if not multiple times before you begin. Also, be sure and start a build thread on the John L Sayers forum for advice from a larger pool of experts than you'll find here on TB.

Questions:

• Why are you considering RC2? Hat channel isn't that much more expensive and offers better performance.
• Is your plan to use channel mounted directly to the studs? If so, consider Whisper Clips or any of their less expensive but less well-performing competitors. It will increase performance considerably, although it will eat up more of your floor space.
• You describe "strategic" sound isolation. Unless you're building a booth the isolation can't be strategic and also be effective. I'd either plan on gutting the room or building a separate iso booth within the room.
• You describe RC2 and 5/8" drywall. If you mount RC2 to the studs and then put up a single layer of 5/8" drywall you'll get some isolation, but don't expect miracles. A drumkit will blow right through that. Do you have room for multiple layers of drywall? If so, and isolation is a concern, double-up the drywall and put Green Glue in between the layers.
• There are many retailers that sell this stuff. Trademark Soundproofing out of New York is where I bought all of my hat channel, Whisper Clips, putty pads for light fixtures and outlets, Green Glue damping compound and Green Glue sealant. They were great to work with.
• If your goal is to do the whole room and the iso booth idea isn't appealing, how are you going to deal with the door, light fixtures, electrical outlets and those curious soffit/chase areas that poke out of the walls at an angle? Further, if you want to do the entire room, how are you dealing with HVAC and its sound isolation?

On background, I am not going to be recording in this space. There won’t be any drum kits in this space. Studio-quality sound isolation isn’t the goal.

I’ll use this room to listen to music and to practice guitar and bass. When I practice bass, I am often playing along to a click track, drum pattern, or a recoded track. When I play guitar, I am usually playing over bass loops that I’ve built over drum tracks. And when I am listening to music, I tend to prefer more volume than my wife.

My goal with adding mass to the ceiling is to absorb some frequencies locally. My wife’s office is at the furthest corner of the house. So, I have that distance working in my favor. While our bedroom is basically directly overhead, it’s on the second story. So, if I moderate my volumes, I can play and listen to music without bothering anyone.

In terms of sound containment, this room in the basement is already better performing than any other room in the house. Adding an air space and some additional mass in the ceiling should make it a little better. For the best results, I’d have to tear out the existing ceiling. I’m not going there. So, I’m looking for a marginal improvement within the existing room.

The ceiling is already relatively low. Preserving ceiling height is one of the reasons I’ve ruled out a clips plus channel approach. To preserve ceiling height while absorbing some sound, i have two main options:

1.) Install QuietRock on the ceiling, with a layer of Green Glue between the new and existing drywall.

2.) Install RC2 resilient channel and hang 5/8” drywall.

My audio engineer buddy says the latter is the better option. The airspace will be more effective than the Green Glue at sound absorption. Also, the existing ceiling is 1/2” drywall. The additional sheet of 5/8” will vibrate differently than the 1/2” and some amount of phase cancellation will take place.

Trademark Soundproofing sells RC1 channel only. I need RC2 since this is a ceiling.

 

[silky smoove]

Don’t waste money on Quiet Rock. Type X drywall plus Green Glue is far more effective and less expensive.

Adding RC2 without tearing out the existing drywall will leave you with a three leaf assembly. That assembly will be drastically less effective than a two leaf assembly, particularly with respect to low frequency energy. I would not build a three leaf assembly if at all possible. I completely disagree with your buddy. That small added airspace and creation of a three leaf assembly will be outperformed by a two leaf system consisting of two layers of drywall with Green Glue in between on one side, subflooring (likely plywood sheathing) and flooring material on the other side, and hopefully a stud bay completely filled with pink fluffy insulation and not a more rigid insulation such as OC703 or Rockwool. Adding clips and hat channel add air space, but less air space than just the stud bay in its own. The real advantage of using clips and channel, or even just channel is to mechanically decouple the vibrating mass of drywall in your space from the structure by attaching it to more flexible substrate AND by leaving a gap on all edges which you then fill with a permanently flexible sealant like Green Glue’s sealant which is a different product than their damping compound. If you use RC2 direct to the studs it’ll help, but unless you’re increasing the mass I wouldn’t bother. Adding mass and damping is not only cheaper, it’s a much simpler construction project that leaves you with a two leaf assembly that will probably perform better for less money.

Now… Adding mass to the ceiling may help a little, but it does nothing to interrupt the flanking paths of walls that support the floors above, and since the floor above is the same structure as the ceiling, my guess is that you’ll go through the hassle of flying a bunch of drywall, either on RC2 or direct to the existing drywall, you’ll reset all of the light fixtures to be flush with the new drywall, hopefully install putty pads around said light fixtures, you’ll mud, tape, possibly texture and finally paint. After all of that the sound will simply ignore the newly added drywall, finding a flanking path up a stud to the next floor and all of your effort will have made the tiniest of differences despite a ton of work and a good bit of money.

Are there HVAC ducts in the ceiling above this space? If so that’s yet another flanking path to contend with. What about water or sewer pipes? If so, you’ve got the same problem. An electrical chase? Same deal. All of these, if present, can only be addressed if
you remove the existing drywall.

 

[silky smoove]

The additional sheet of 5/8” will vibrate differently than the 1/2” and some amount of phase cancellation will take place.

Rod Gervais, the leading expert on sound isolation and largely regarded as a guru in the field has roundly rejected this premise. He’s the expert and he’s stated that this is simply not how the physics of sound isolation work. I’ll take his word on it over just about anyone’s.

 

[DC in ATX]

Also, relevant for understanding this space: the four walls are basically 160-year-old stone masonry and it’s a concrete slab floor. For the most part, drywall and wood elements and thick carpet are placed in front of the stone and concrete. So, it’s not slap happy or echoing. Listening to the room, I think the boxed out duct work might actually improve the performance of the space as a music room.

 

[DC in ATX]

Rod Gervais, the leading expert on sound isolation and largely regarded as a guru in the field has roundly rejected this premise. He’s the expert and he’s stated that this is simply not how the physics of sound isolation work. I’ll take his word on it over just about anyone’s.

Having consulted a trusted source of my own, I am not here to argue the physics, which I may not be accurately representing here. As a builder by trade, I understand how one would build a soundproof room from scratch. And this isn’t that.

At the same time, the perfect doesn’t need to be the enemy of the good here. My personal experience is that doing something can be better than doing nothing—and sound abatement in the real world (not the studio) is often about incremental improvement.

With that goal in mind, my question remains:

Where can one source RC-2 Resilient Channel?

 

[silky smoove]

Also, relevant for understanding this space: the four walls are basically 160-year-old stone masonry and it’s a concrete slab floor. For the most part, drywall and wood elements and thick carpet are placed in front of the stone and concrete. So, it’s not slap happy or echoing. Listening to the room, I think the boxed out duct work might actually improve the performance of the space as a music room.

You’re confusing acoustic treatments and sound isolation with this statement. The important takeaway is that the masonry and concrete will be helpful in terms of sound isolation. The ceiling construction methods discussed will be only marginally helpful and likely not worth the money, time or effort given that adjacent flanking paths will not be addressed. Either do the whole thing, build an iso booth, or do nothing. Anything in between those choices isn’t going to yield a good result, let alone perfect.

At the same time, the perfect doesn’t need to be the enemy of the good here. My personal experience is that doing something can be better than doing nothing—and sound abatement in the real world (not the studio) is often about incremental improvement.

This won’t be incremental improvement. It will be minuscule unless you address the space as a system. Your comment above about the ductwork being inside of those angled wall chases points to even more flanking paths than the vertical wall assemblies thus making treatment of the ceiling alone even less effective for isolation purposes.

With that goal in mind, my question remains:

Where can one source RC-2 Resilient Channel?

I answered that in the first reply to the thread. Still, if you’re set on doing something to the ceiling, don’t build a three leaf assembly. Add mass and damping. You’ll get similar if not slightly better results (however minor) and it will be far less invasive and time consuming. You’ll also retain more ceiling height.

 

[DC in ATX]

Doing nothing for the time being is a perfectly reasonable option.

At normal listening volumes, I don't get a lot of flanking noise out of this room. The exception is the doorway into the unfinished portion of the basement, which I am addressing with a solid door plus a sound absorbing panel.

The question of "where does the noise leak out at higher volumes?" is yet tbd. As is the bigger question: "Is the noise that bleeds into the living room disturbing anyone in any of the rooms on the second floor of the house?"

 

[silky smoove]

Doing nothing for the time being is a perfectly reasonable option.

Hopefully that works out. It’s always the best option, provided it actually works

which I am addressing with a solid door plus a sound absorbing panel.

A sound absorbing panel for the door? Can you link to such a product? If you want to sound isolate a door you typically have two options; purchase a sound isolation door, or build one. Adding a panel of any sort that can be supported by an existing door will be of insufficient mass and lack the proper multi-layer seals on the side to be of any real effect.

The question of "where does the noise leak out at higher volumes?" is yet tbd.

Actually the physics on that are quite clear and are identical in every space on the planet. Wherever the isolation is weakest. Sound is super lazy, especially at lower frequencies. Treat the ceiling and it’ll use a flanking path up a wall stud to the adjacent floor. Treat the walls and it’ll run down a duct or a water pipe. The list goes on until you’ve addressed the space as a whole. That’s why sound isolation is such an expensive, complicated, time consuming and difficult enterprise.

As is the bigger question: "Is the noise that bleeds into the living room disturbing anyone in any of the rooms on the second floor of the house?"

Absolutely. Definitely the best place to start. I’d run some normal use tests and do an after hours test to see if using the space when other people in the house are in bed causes any problems. Nothing worse than trying to sleep and you can hear low end rumble coming through the structure. Hopefully that goes well and you can save yourself some effort.

 

[DC in ATX]

This is the product that will hang over the door:

isolé® Sound Barrier Sheets

I found one new on eBay for $40. Listing suggests it had been donated to a dog shelter for a fundraiser.

These are basically two doors beyond the sound barrier sheet, one between the conditioned and unconditioned basement and another between the basement and the rest of the house. Except for a few pocket doors on bathrooms, which are modern interventions, the doors throughout the house are solid wood.

 

[silky smoove]

This is the product that will hang over the door:

isolé® Sound Barrier Sheets

This is an acoustic treatment, not a sound isolation measure. You can tell because they reference the noise reduction coefficient (NRC) as opposed to sound transmission class (STC) or a more helpful transmission loss chart. NRC is a method of describing absorptive characteristics of a product, not their ability to reduce transmission. In other words, this may help to change the reflection decay times within the space but it won't do anything to prevent sound from entering or exiting the space.