New room construction: overall acoustics

[poutanen]

Hey All,

Well I'm planning on taking advantage of the tax credits this year and I'm going to finish half of my basement into a studio. I'm not hardcore into music recording or anything, just want a place to play guitar, drums, and a room that can handle my pro-audio stuff (Yamaha mains, Yamaha 18" subs, Behringer amps).

At the moment, I've got a totally clean slate, so I want to type out my current plan, and I'd appreciate any feedback please!

- walls: 2x4 stud, insulate with the standard pink, use drywall for walls (should maybe use thicker drywall than normal?)

- ceiling: looking at a drop ceiling, however I don't have much room, so looking at the PVC type that screws right into the stringers (like CelingMax). The PVC should vibrate less than metal hopefully. Will use pink insulation (or ???) in ceiling. Looking into various options for acoustic ceiling tiles.

- floor: wanting ideas here. Was thinking 1/4" cork, then thick underpad, then some berber carpet.

- doors: solid wood, with some weather stripping around all edges to seal in some sound

My first goal is to limit sound escaping the room, and my second goal is to have the room sound good. After I figure out the main construction, I'll look at bass traps in the corners, wall treatments, etc. I'll have a couple big couches to absorb some sound, maybe it's possible to add bass absorbtion material into the construction of the couch itself? I know you can buy bass trap coffee tables, wonder if same stuff could be used for other purposes.

 

[bpape]

If you're serious about isolating sound getting out - rethink the idea of a drop ceiling. Bass will go right through it like it's not even there. Stopping bass takes mass - that means drywall.

For better isolation, consider 2 layers of drywall and/or using firring strips perpendicular to the joists and mounting the drywall on that for a bit of extra decoupling.

Insulating all of the cavities is definitely something you want to do.

Bryan

 

[Exit]

I have read a lot of posts that have had good things to say about using Green Glue with double layer drywall for soundproofing. Google Green Glue and there are several retail suppliers and references. The main site for Green Glue is below:

http://www.greengluecompany.com/

The price adds up but it looks like it is easy to do.

 

[highfigh]

Firring strips won't decouple the ceiling but resilient channel will help. Best way is to build a "Box in a box" that's totally separate. If you drywall the underside of the floor joints (after installing a conduit of some kind if the cable runs will be perpendicular to the joists), frame the room and install a 3/4" particle board layer before the drywall, it'll stop more sound than the drywall layer next to the framing. A drywall lift works for this, too.

How does this qualify for tax credits? If you won't use this space for business, AFAIK, only adding energy efficiency qualifies.

 

[poutanen]

If you're serious about isolating sound getting out - rethink the idea of a drop ceiling. Bass will go right through it like it's not even there. Stopping bass takes mass - that means drywall.

For better isolation, consider 2 layers of drywall and/or using firring strips perpendicular to the joists and mounting the drywall on that for a bit of extra decoupling.

Insulating all of the cavities is definitely something you want to do.

Bryan

Unfortuately, I need access to the ceiling for wiring, plumbing, etc. So I need to have a removable ceiling of some sort. I could add extra insulation, or I'm open to alternate methods. Is there a type of insulation with more mass/sound deadening properties?

I suppose it'd be possible to lower all the wiring below the joists, install some MDF/plywood or something, then use 2x2 firring and install a drop ceiling below that (having the utilities run in between MDF and drop ceiling...)

 

[poutanen]

Firring strips won't decouple the ceiling but resilient channel will help. Best way is to build a "Box in a box" that's totally separate. If you drywall the underside of the floor joints (after installing a conduit of some kind if the cable runs will be perpendicular to the joists), frame the room and install a 3/4" particle board layer before the drywall, it'll stop more sound than the drywall layer next to the framing. A drywall lift works for this, too.

How does this qualify for tax credits? If you won't use this space for business, AFAIK, only adding energy efficiency qualifies.

I like this idea, along with the green glue idea. I've read about dual drywall layers, wonder if there's a better substrate than drywall. I'd assume MDF would have more mass than most other reasonable (ie. cost friendly) materials.

For the tax credits, keep in mind I'm in Canada. For the 2009 tax year, we get a $1000-10000 tax credit for any renovation projects done by (I believe) Feb 2010. This covers material and labour, but labour must be done by a GST registered company to qualify. My dad and buddy will be helping, so it's only material costs I have to worry about. It's a 15% tax break, so if it costs me $3000 in materials to do everything, I'll get $450 back on my 2009 taxes. Also, I'm going to do a home energy audit, and they'll say that insulating my basement walls will qualify for a grant, so I should get a couple hundred $$$ back from that too.

It wouldn't be worth it to do the renos just for the sake of taking advantage of tax credits, but I wanted to do this anyway, so I'm just speeding up the process a bit to take advantage. Also my heating bills should go down a bit... my basement's quite cold at the moment.

 

[bpape]

Actually, firring strips run perpendicular to the joists are a poor-mans version of decoupling with channel. RC type channel is a guess at best, is very unpredictable, and very easy to short out. RSIC-1 and firring channel is far superior and more predictable.

Sounds like a moot point though if he needs access to the above.

Bryan

 

[Drako60]

There is also a drywall called QuietRock, which is two layers of sheets rock with a sound isolation between them.

I don't know the effectiveness vs cost with using QuietRock vs Green Glue, and they recommend 24 inch on center studs, with i believe 3 and 1/2 inches of insulation with the QuietRock, they even have a THX certified version if that makes a difference.

If i had a clean slate i think i would use 2x6 studs on 24 centers, with pink insulation, and 5/8s QuietRock on both sides of the wall, or perhaps 2 sheets 1/2 drywall with green glue between them on both sides, over kill probably.

 

[poutanen]

Thanks everybody, this is the feedback I need. My prime reason for keeping the sound IN the room is due to a neighbour on one side. His house is about 30 feet away, and I don't want to bug him, the other side is fine, there's about 100 feet to the next house.

So for this purpose, the sound deadening on the walls may be just as important as the ceiling.

I suppose with 2x6 studs I could fit more insulation in there? And 24" oc would give less overall wood to transfer the sound to the outside? (vs. 16" oc)

 

[Drako60]

with 24 on center the waves have to travel farther before they bounce back and the less vibration they can impart to the framing so there is less vibration and structural transfer, or something to that effect.

with 2x6 you are able to use thicker insulation, with 2x4 you are going to be limited to about R19 fiberglass insulation, with 2x6 you should be able to get R25 insulation, with 2x10 i know you can get R30 which is great for keeping heat in and cold out.

I know that the bass traps i've seen use Owen Corwin 703 or 705 fiberglass panels, which is i believe 3 pounds and 5 pounds per cubic foot (might be cubic inches), so lower density might be better for the higher frequencies i'm completely unsure on this aspect.

there are two articles on audioholics if you are doing new construction
http://www.audioholics.com/education/acoustics-principles/room-acoustics-isolation-noise-control

http://www.audioholics.com/education/acoustics-principles/a-guide-to-sound-isolation-and-noise-control

both have construction methods, as well as things some might not even consider like isolating the electrical outlets and lighting fixtures, depending on how isolated you want it to be.

 

[Duff man]

with 2x6 you are able to use thicker insulation, with 2x4 you are going to be limited to about R19 fiberglass insulation, with 2x6 you should be able to get R25 insulation, with 2x10 i know you can get R30 which is great for keeping heat in and cold out.

A 2x4 wall will hold R12 of standard pink or R14 of Roxul Safe 'n' Sound. Roxul is a better choice not only for the added insulation value, but because it has superior sound deadening properties over standard fiberglass insulation...and it's available in Canada at all the box stores.

 

[poutanen]

A 2x4 wall will hold R12 of standard pink or R14 of Roxul Safe 'n' Sound. Roxul is a better choice not only for the added insulation value, but because it has superior sound deadening properties over standard fiberglass insulation...and it's available in Canada at all the box stores.

Well I did my ecoenergy audit the other day and they want R-24. So I think my only option is that urethane foam insulation.... got a guy coming to give me a quote in a few mins.

 

[Duff man]

Well I did my ecoenergy audit the other day and they want R-24. So I think my only option is that urethane foam insulation.... got a guy coming to give me a quote in a few mins.

Spray insulation can be very expensive. If the quote comes in higher than you were hoping, there are 2 other options to achieve R24:

Build a 2x4 wall about 3" away from the foundation and put the R12 (or R14) insulation horizontal between the foundation and new wall, and then fill the cavities with another R12 (or R14). Total insulation value would be R24 or R28.

Or...put 1" of foamboard against the foundation (R5), and then build a 2x6 wall filling the cavities with R20, total R25.

 

[bpape]

Also, spray foam insulaiton, while a great heat/cold barrier, is almost useless in terms of acoustical value.

Bryan

 

[poutanen]

Spray insulation can be very expensive. If the quote comes in higher than you were hoping, there are 2 other options to achieve R24:

Build a 2x4 wall about 3" away from the foundation and put the R12 (or R14) insulation horizontal between the foundation and new wall, and then fill the cavities with another R12 (or R14). Total insulation value would be R24 or R28.

Or...put 1" of foamboard against the foundation (R5), and then build a 2x6 wall filling the cavities with R20, total R25.

It's actually only going to cost about $2500 for the spray foam, of which the government will cover $2000 if I get it R-24 or more!!!

I was talking with them last night, and they suggested 24" OC studs instead of 16" (something echo'd from here), and they suggested running them with the 4" side touching the drywall, about 2" out from the wall, which would effectively decouple the wall from the outside wall except for the ceiling and the floor.

I'm still waiting for my complete quote from them but I'm strongly considering this. Plus with the ontario home reno tax credit I'll get 15% back on whatever I spend on materials and labour...

 

[highfigh]

Hey All,

Well I'm planning on taking advantage of the tax credits this year and I'm going to finish half of my basement into a studio. I'm not hardcore into music recording or anything, just want a place to play guitar, drums, and a room that can handle my pro-audio stuff (Yamaha mains, Yamaha 18" subs, Behringer amps).

At the moment, I've got a totally clean slate, so I want to type out my current plan, and I'd appreciate any feedback please!

- walls: 2x4 stud, insulate with the standard pink, use drywall for walls (should maybe use thicker drywall than normal?)

- ceiling: looking at a drop ceiling, however I don't have much room, so looking at the PVC type that screws right into the stringers (like CelingMax). The PVC should vibrate less than metal hopefully. Will use pink insulation (or ???) in ceiling. Looking into various options for acoustic ceiling tiles.

- floor: wanting ideas here. Was thinking 1/4" cork, then thick underpad, then some berber carpet.

- doors: solid wood, with some weather stripping around all edges to seal in some sound

My first goal is to limit sound escaping the room, and my second goal is to have the room sound good. After I figure out the main construction, I'll look at bass traps in the corners, wall treatments, etc. I'll have a couple big couches to absorb some sound, maybe it's possible to add bass absorbtion material into the construction of the couch itself? I know you can buy bass trap coffee tables, wonder if same stuff could be used for other purposes.

Again, ANY physical connection will transmit impact and low frequencies to the structure and structure-borne sound travels a lot faster than airborne. You'll need to heat and cool that room separately too, because the ducts won't do much to stop anything from getting to the rest of the house. You can use rubber isolation pads under the wall's sole plate if you want. If you frame the wall and have the space for it, use 2x8 for the sole and 2x4 for the studs, but stagger them, so they still have normal 16"o.c. spacing but each side doesn't line up with the other. This allows you to put insulation between the studs from each side. If you put 3/4" particle board on the studs before the drywall, it stops a lot more sound than just two layers of drywall. Your lights will also be a source of leakage, so wall sconces and floor lamps are a good choice. Use the coolest light sources you can find, because tehy will add to the heat buildup. Your door should be at least a solid core with weatherstripping and if possible, use two doors with an airlock.

It's not the overall SPL that will be a problem, it's the low frequencies and drums that you need to block and the combination os mass and decoupling will make a big difference.

As far as the room itself, you'll want to deaden it more if you plan to play at high volume. If you plan to record, the lowest volume possible that gets the sound of each instrument will be best. If you find that you need to crank the guitar amps, I would make an isolation space and add ambiance later. Your room won't be large enough to get great reverb, anyway. Look online for a room mode calculator so you can find the dimensions that will keep standing waves as evenly distributed as possible. You will need bass traps, too. This will allow the low frequencies to be as even as possible. It's better to make the room more acoustically dead than too live- you can always make movable frames with a hard surface using pegboard covered with fabric on one side and acoustically absorbent on the other, using whatever materials you want. This is called a 'gobo' and they're common in studios. They make the room much more versatile and you can use them not only to alter the acoustics but you can also isolate with them.

 

[highfigh]

It's actually only going to cost about $2500 for the spray foam, of which the government will cover $2000 if I get it R-24 or more!!!

I was talking with them last night, and they suggested 24" OC studs instead of 16" (something echo'd from here), and they suggested running them with the 4" side touching the drywall, about 2" out from the wall, which would effectively decouple the wall from the outside wall except for the ceiling and the floor.

I'm still waiting for my complete quote from them but I'm strongly considering this. Plus with the ontario home reno tax credit I'll get 15% back on whatever I spend on materials and labour...

IIRC, the government is trying to make it easier for people to make their homes more energy efficient, not so they can get money to cut the cost of their recording/music room.

 

[highfigh]

Spray insulation can be very expensive. If the quote comes in higher than you were hoping, there are 2 other options to achieve R24:

Build a 2x4 wall about 3" away from the foundation and put the R12 (or R14) insulation horizontal between the foundation and new wall, and then fill the cavities with another R12 (or R14). Total insulation value would be R24 or R28.

Or...put 1" of foamboard against the foundation (R5), and then build a 2x6 wall filling the cavities with R20, total R25.

R24 and R28 are for thermal insulation, not blocking noise transfer. Those numbers mean little when you're dealing with acoustics. Sure, thicker blocks more of certain frequencies but you need to look into NRC and STC.

 

[poutanen]

IIRC, the government is trying to make it easier for people to make their homes more energy efficient, not so they can get money to cut the cost of their recording/music room.

Considering I've got a 50+ year old house with an uninsulated cinder block foundation, my prime reason for doing this is to increase the energy efficiency. But I might as well make it a space that I want while I'm in the process of it!

Also, I won't be recording in there any time soon.

It's just somewhere I want to put my bigger stuff and my guitar and maybe a drum kit so I can screw around on the weekends without my neighbours hating me... I'll think about recording if I end up playing something worthy of it! lol

 

[highfigh]

Considering I've got a 50+ year old house with an uninsulated cinder block foundation, my prime reason for doing this is to increase the energy efficiency. But I might as well make it a space that I want while I'm in the process of it!

Also, I won't be recording in there any time soon.

It's just somewhere I want to put my bigger stuff and my guitar and maybe a drum kit so I can screw around on the weekends without my neighbours hating me... I'll think about recording if I end up playing something worthy of it! lol

Having posted this, you know that the first time you get to play in that room, you'll play like never before and wish you had a way to record it, right?