[mgalusha]

OK you acoustics guru's, I'm hoping to start on my dedicated music room this month and had planned on using traditional methods of sound proofing to assure domestic tranquility. While looking for information on building new stairs for my deck I saw a link to a company called Quiet Solution. They make a product called QuietRock, basically a constrained layer drywall which they claim (and have measurements for) can offer significant sound reduction with "normal" construction techniques instead of resilient channel and such.

I don't know the costs yet though they show "as low as $39.95/sheet", which isn't cheap but for a single dedicated room isn't horrible either.

Has anyone used this or have any experience with it?

main page -> http://www.quietsolution.com/html/quietrock.html

test reports -> http://www.quietsolution.com/html/noise_samples.html

noise samples -> http://www.quietsolution.com/html/test_reports.html

Mike

[MarkM]

Here is another interesting product, any have experience with either?

http://www.supressproducts.com/products/index.htm

They claim a single layer of this drywall is equivalent to 6 layers of drywall.

Thanks

[ctviggen]

Also, check out:

green glue

They have comparisons on their website, although I don't think with either of those

[bpape]

It's all a matter of HOW quiet you want it to be.  The Quiet Rock can do a good job if you use the stuff that's more like $100/sheet.  The Green Glue with 2 layers of std drywall does as good or better for less money IMO.

Bryan

[BRILEY804]

Guess I will throw another idea at you and this would actually do two things for you :

http://www.icynene.com/        When you click on the link, look up at the top and you will see Products, click on that and then click on the one that says ' The Icynene Insulation System ' and from there you can watch a video.       Not only would this process sound proof your room for you, but would also save you money.       

I did some looking around last night on the web and found a site where you can do this process yourself, but they recommend people that are trained in doing this as the job itself can be quite messy and doesnt clean up easily.

[bpape]

Unfortunately, those spray insulation products are great for thermal performance but terrible for acoustical isolation.  They are a closed cell type of foam that will provide basically zero in terms of any acoustical absorbtion.  Standard wall insulation will perform much better in the wall cavity.  If you want a little more density, you can use R-19 in the 3.5" cavities.

Bryan

[Daygloworange]

mgalusha,

I have 2 friends that own acoustics companies. Both are good friends of mine. We've spoken on the topic of soundproofing numerous times. The number one thing to stop sound transmission is mass. Period. The other things are decoupling, and air leaks. The specialist drywall companies have overblown claims. Look at the STC ratings of the Quietrock 530. They claim an STC of 55 to 74. That is a huge gap.

I have over the years done quite a few jobs with one of my friends as a project manager. I'm very familiar with the Eckel line of soundrooms. We've done dozens of installations over the years. Eckel soundroom panels contain drywall, and rigid fiberglass, wrapped in steel. They weigh several hundreds of pounds each. All the joints are gasket sealed. We've done laboratory and industrial testing ones where there are two chambers, one inside the other, decoupled from each other and on special decoupling platforms. These weigh several tons.

We dismantled 3 rooms last September that we put up 5 years ago when this automotive supplier moved to a new plant.





Although it's not my field, I have learned a number of important factors in soundproofing while building and renovating rooms for residential, commercial broadcast, and post production facilities.

Staggered stud construction is a great method for wall construction. The best way is not use a common top and bottom plate, but two independant walls with an air gap. We use a 1/8" thick rubber product called "symar" between the studs and the drywall. Two layers of 5/8" drywall, the second layer siliconed over the first. The cavities are filled with standard fiberglass insulation.
 
Aside from mass, the second most important thing are air leaks. We silicone everything. The top and bottom plates, the joints in corners. We use sealed electrical boxes and seal them to the drywall. This is really important. There have been times when we had to drill through to add something at a later point, and you would not believe how much sound comes through a 1/2" hole in the wall.

We also recommend against recessed lighting. They will not guarantee STC's if there are those. Track lighting is recommended, as the breach to the envelope is minimized. Doors are the most problematic areas, and where you loose the most STC. The heavier the door, the better. Two doors are often used. Attention to airgaps around the door frame, and the sealing of the door edge to the doorstop, and sill.

We have on occasion used resilient channel with drywall, but often due to budgets, we use the symar layer instead.

You don't need exotic materials to achieve great results. The principles are quite simple. Mass, decoupling, and avoiding air leaks.

I haven't used the green glue, but have heard lots of positive things about it.

Keep us posted on the construction, and good luck.  

Cheers

[JLM]

I built a listening room in the basement two years ago:

The room was sized as per Cardas (8 foot x 13 foot x 21 foot).

Insulated (fiberglass batts) staggered 2x4 stud walls (16 inches on center) on 2x6 top/bottom plates with 1/2 inch drywall.

Insulated fiberglass exterior door with weather seals.

Insulated flexible ductwork (can only hear the air flow when on a chair near the diffuser).

Three dedicated 20A, 12 gauge electrical circuits (the heaviest allowed for residental construction) with one cryo'd 20A hospital grade receptacle per circuit.  These circuits are tied to their own common ground.

My downfall was the ceiling, as the builder refused to use resilent channel for fear of the drywall cracking, and it contains six recessed can lighting fixtures (even though they're rated to be in contact with insulation and to be air-tight).  The lesson here (as you stated) is to stick to conventional methods (that the builder is comfortable with).  Even though there is 8 inches of fiberglass above, I hear every footstep, washing machine, dryer, and vacuum.  The green glue idea would be of great help, thanks ctviggen!

Except for the ceiling, the room is a big success.  The additional cost to "audiophile it" was minimal (maybe $200 for the walls plus $100 for the receptacles) as it was going to be finished off anyway (the door was cheaper than the cherry doors in the rest of the house).  At first the isolation was almost spooky.  Now I can listen when I want and at pretty much any volume level (I get up by 5:00 everyday).  But the biggest benefit is the lack of background noise to overcome, so I can hear more at lower spls and therefore hear a wider range of dynamics.


Lots of good ideas here, but some are very expensive.  Sealing the electrical boxes seems like a good idea (all the adjoining spaces to my room are unoccupied, so that wasn't needed.  The symar sort of stuff I looked at was very costly.

Had I to do it over again I'd consider 5/8 inch drywall, 12 inch stud spacing, and would certainly fix that ceiling the first time.

[bpape]

Even better idea to do surface mount outlets so you have no holes.  Sealing a 1/16" plastic box will help with air leaks but bass still goes right through it.  The same is true for lighting.  Sconces mounted on false columns work great.  Building soffits AFTER the room is already sheetrocked and sealed also allows cans in the soffits with no holes in the sealed room.

Mass is absolutely your friend as is decoupling.  However, mass is not everything.  A solid concrete wall is pretty massive as is a concrete floor, but they'll both still transmit sound.  It has to be the right kind of mass, decoupled properly, and allowed to damp itself.  The Green Glue layer allows the 2 layers of mass to move independently and not resonate at the same exact frequency (think of a spring  connected  to a weight with another spring and weight hanging off of that).  Also, the depth of the cavity between the inner and outer layers of the walls determines somewhat the resonant frequency of the cavity.  The lower the better (deeper is better).

Also, the spacing between studs plays a role.  However, if you look at the research, WIDER spacing works better (again, it drops the resonant frequency).  If you want to break it up even more, do your walls with staggered spacing.  You can do a 16", then 24", then 16", etc.  Or, you can do front and right wall with 16" and back and left with 24".   That will put the resonance of 2 of the walls lower and also cause the 2 sets of walls to have different resonant frequencies to further break up transmission.  Every structure has good and bad places for transmission losses.  The idea is to get the broad benefit and spread the bad so it doesn't build up and all come through when the speakers hit that one note.

Sound moves not only through air but also through structure.  Proper framing techniques and isolation of the framing from the rest of the house will help with structure borne noise.  Building your walls (2 separate ones) on a floated floor will also help a ton.  Then you're down to dealing with the transmission through air. 

Remember the old addages:

- A system is only as good as it's weakest link.  You can do whatever you want to the room but if you poke holes in it sound is going to get out - and worse IN from the outside.

- Think of your room as an aquarium.  It doesn't matter how big the hole is or where it is, you're going to get wet.

Bryan

[Don_S]

What is the goal?   A listening room or a soundproof isolation chamber?

[Daygloworange]

What is the goal?   A listening room or a soundproof isolation chamber?

Soundproofing the room will lower the noise floor which is beneficial to the listening environment as well as benefit people outside the room. So there really is not much of a difference as to what the reasons are.

Bryan, great suggestions. The only other one I would add is doing a decoupled ceiling for those doing a room in their basements. You lose some ceiling height, but benefit from substantial gains in isolation.

Cheers

[honesthoff]

Bryan, great suggestions. The only other one I would add is doing a decoupled ceiling for those doing a room in their basements. You lose some ceiling height, but benefit from substantial gains in isolation. 

Cheers

DGO, Would hanging Chicago grid from pencil rod then rocking over the grid work as a decoupling method?  I've been considering this, and I really hate the look of most acoustical ceiling tile.  I could tape in some access panels in the two areas I would really need them.

[bpape]

If you have to have a drop ceiling, then just set your expectations accordingly.  People have done the drywall in the grid and it's certainly better than just tile but watch for rattling and make sure you really beef up the number of hangers.   There are actually special hangers made with springs on them for just this purpose. 

The decoupled ceiling is absolutely a good idea.  PAC International RSIC-1 clips with hat channel provides this isolation in a much much more controlled and predictable manner than RC.  With RC, it's a crap shoot as to where the resonances will be since it's so dependent on exact mass, exact spacing of screws, etc. - not to mention that it's really easy to screw up the isolation with just 1 or 2 misplaced screws.    If you want the poor mans way to do it, you can use 1x2 firring strips perpendicular to the joists above and screw the drywall to that.  It's not as good but it does minimize the surface area touching the studs above.

Another trick for isolation (though a pain in the arse to do) is to cut drywall the width to fit between the joists and Liquid Nail them to the underside of the subfloor above.  That will over double the mass of the subfloor and again, drop the resonant frequency of the entire structure.  The floor will have a different resonance than the double drywall below (a good thing) and different yet from the cavity between.  The additional insulation makes the cavity appear acoustically deeper and damps any echoing inside the cavity (think of a bass drum with and without a pillow in it.)

Bryan

In any case, make sure you fill the cavity above FULLY with insulation.  You don't need to compress it but we want it full.

[Daygloworange]

DGO, Would hanging Chicago grid from pencil rod then rocking over the grid work as a decoupling method?  I've been considering this, and I really hate the look of most acoustical ceiling tile.  I could tape in some access panels in the two areas I would really need them.

Do you mean putting drywall panels in the space of acoustical ceiling panels on a standard drop ceiling? There's more mass to the drywall, so it'll work better, but not by much. You've effectively cut a grid work of 1" gaps in your drywall, and inserted thin aluminum metal strips. Real bad. Again, the rule of air gaps applies here.

I can't stress enough the importance of sealing the envelope of the room. On occasion, we have had to go in to a job where someone bought a used soundroom and someone else installed it. The customer calls and asks for help because it is not meeting their expectations. There is no choice but to completely dismantle it, because you have to check to make sure all the seals are there, intact, and not damaged. All the panels joints are double sealed. Bottom, top, sides. One seal around the perimeter facing out, one seal around the perimeter facing in. If one seal is not there, it's a big deal. You might as well leave the door open to the soundroom.

A more detailed description of a decoupled ceiling is where you build a standard wall type framework and couple to the walls instead of the floor joists from above. You do need to tie  the framing in to the floor joists every so often to prevent the ceiling from sagging from the weight of the drywall, but you do that with wire. There are also wiring systems with springs as an isolator for decoupling that they use in real heavy duty studio type floating rooms, but you'll acheive most of the benfit from just using wire.

In the example I gave earlier, I forgot to mention that even though you have 2 layers of drywall, you still tape the joints on the first layer, even though it won't be seen. You also stagger the seams between layers of drywall. And you overlap and tape the layers of symar. I'm not kidding about sealing air leaks.

Cheers

[Papajin]

I'm looking at building a listening room in my basement, and am rather interested in this subject myself.  I was looking at possibly these Kinetics IsoMax clips for walls and ceiling (2 layers of drywall, green glue between, edges sealed, etc.)  I'm not sure what I should do with the floor at this point -- On the one hand I wouldn't mind doing something with it as most finished basements I've been in, the cold seems to seep up through the floor during the winter, and I'd like to reduce that.  On the flip-side though, raising the floor and lowering the ceiling could have a fairly negative impact on ceiling height.  Anyone have any experience with cement slab as far as sound transmission goes?  I'm in a townhouse with units on either side of me, so my intent is to isolate my listening room as much as possible from the neighboring structures as well as the upstairs of my own.  My basement is also what's called a "walk-out basement" which means that the entire backside of it is standard framing at the moment rather than cement like you'd see in a fully enclosed basement.

On doors, this place seems interesting, but I hear prices start at $2500 which is a bit spendy for a door.  I haven't really researched what's available much yet in this area, but it's going to be important, I'm sure.

[bpape]

The Kinetics clips are OK - certainly better than nothing.  The PAC RSIC-1's are better - less contact, different resonances, etc.

As for the floor in a townhouse, yes - the slab will transmit sound pretty well.  Look at a product called Dri-Cor.  It's sold at Home Depot.  It only loses you 3/4" or so, gives you the warmth, the feel of a wood floor, and allows you to build walls on top of it for pretty good isolation at a reasonable price.

Bryan

[JLM]

The acoustic design of the room is is poorly understood by most (including me  ).  Bigger the better, but proper proportion is important too.  For smaller spaces retangular rooms are the most researched.  If I'd had a bit more room, the back wall would have been built on a skew to the other walls to break up standing waves.  But for the most part rooms are treated after the fact with either absorptive or diffusive methods.


Papajin,

Take care to insulate the joist spaces that adjoin the neighbors (I've heard lots of sound transmitted through there).


BTW much of the commercial drop in ceiling tiles used are gypsum substrate with various finishes, although most are mineral wool.  Avoid cheapy fiberglass substrate as they sag in time and have only a thin vinyl facing.

[TONEPUB]

One other thing that really helps is to glue the drywall down to the studs
and screw them in instead of using a nail gun.  I got much more solid
walls going down that path...

Good luck on the project!

[mgalusha]

Thanks for all the input, greatly appreciated. The room will be in a basement and will be my dedicated man cave for listening to music. I'd like it quiet enough to block out household noises and of course to keep my music from impinging on my wife too much. Our basement is divided into two sections, one fairly large at about 1500-1600sqft and the other about 450sqft. The smaller room is basically a concrete square, 21ft x 21ft and most of the ceiling is 10ft. The master bedroom is directly above most of this room, so unless it's bed time the room is not occupied. The washer/dryer sits over what will be the entry hall, so the double wall should, I hope, block most of that. A portion of the ceiling is lower to accommodate the HVAC and steel beam but that is above the entry hall as well.

Playing with the mode calculator from Real Traps indicates that 20'4" x 16' will give a pretty even distribution of the modes and allows for a double wall for the entry doors and a hallway. The room has one existing window, which I want to retain as part of the back wall and of course an existing door.

It certainly sounds like two sheets of standard drywall and Green Glue sandwich is a much better way to go than the QuietRock stuff. For the ceiling I'll use some type of hangers, probably the ones Bryan is suggesting. One question on hangers, the house uses engineered joists instead of solid wood. Is there any particular hanger requirement?

The floor is also a question. Our old house just had pad/carpet on the floor and it seemed fine. I have no objection to putting something over the slab but of course don't want to create any additional resonance.

Image below is a rough draft of what I think it will look like.



Thanks again for all the input. Part of the challenge will be finding a contractor who will actually build it to my specs. Should prove entertaining.

mike

[brj]

Mike, it looks like you have the width to realistically consider angling the walls outward from front to back.  With 10' raw ceilings, you could even slope the finished ceiling upward from front to back, perhaps from 8' above the speakers to 10' at the back wall.  I have no idea how much additional cost would be involved, but you may want to at least ponder the option.

Hmm... if you ever wanted to consider a dual purpose HT setup, the 8' height at the front of the room when implementing a sloped ceiling would give you space to mount a fully retractable screen above the finished surface!