Dampening Noise From Basement

[Chris Jenkins]

My shop's in the basement and I know noise can be a problem on the first floor directly above. I know there is no way I can minimize sound enough in the basement that I can't be heard only a few feet above me.

My concern is dampening the noise so it is lower on the second floor of my house. I just recently noticed how loud it is when I was upstairs and someone was in the basement.

My thought is most of the noise is traveling throught the duct work. Is it worth putting in a drop ceiling? Does this dampen noise enough?

Would framing around the ducting in the basement (with insulation and 1/2" drywall) improve this enought to dampen noise on the second level better than a drop ceiling?

Come to think of it, I would have to cover all the branches coming off the main run as well. (not very visable in the pic below.)

60328

[Gary Keedwell]

Do you have insulation between the joists in the basement ceiling? Fiberglass insulation is an excellent noise barrier.

Gary K.

[Dave Buffington]

people building space for music recording are all over this topic, i have done a lot of research...

You can't ever really soundproof in a normal house, so you are looking for as much sound absorbtion as possible. Sounds travels through solid material like floor joists and wall studs. The best sound dampening comes from two decoupled walls with absorbtion between.

Absorbtion is done via mass. One of the best materials for this is high density fiberglass insulation, like owens corning 703. You won't find it at box stores, usually it is avialbale from commerical suppliers, but most areas have something fairly close by. This is also known as "rigid" fiberglass because it is dense and not the fluffy stuff you find elsewhere, but not the foam stuff that goes over house sheathing.

There is a natural cotton insualtion material with great nosie absorbtion as well, I forget the name.
For the best absorbtion, you want 4 inches of this stuff (6 or 9 pund per square foot) with a air gap (4inches if possible) behind. This will give the
best low frequency absorbtion.

here is what i would do if possible:

Get a bunch of owens corning 703, double up 2 inch panels or get 4 inch thick panels. Install these about 4 inches below the bottom of the floor above, so probably about half way up the joists, do this from end to end of the basement. Then if possible, put a double layer of drywall (staggering joints between layers) along the joists for a ceiling.


Now, that will get you significantly less noise, but the drywall will still transfer directly to the joist to the floor etc. So if possible, drop another ceiling below that. If you used the standard metal frame acoustic tile hanging from metal wire, that would be pretty good. But if you could put an air gap filled with fluffy insulation, and then a layer or double layer of drywall below THAT, you would probabaly have something you would be able to say is significantly quieter.

Now then you will still have sounds transfering through the outer walls... but without building a hwhole house around decoupled walls and such (which many people who want to build home music studios do, to great expense) you will never really be able to beat that.

Dave.

[Chris Jenkins]

Gary - I do not have any insulation between the joists at this point. I am still running piping and electrical through it as of now. I did however put some regular insulation in at my last shop (also a basement shop) that filled the entire joist space. My wife said it did little to nothing.

I believe the mistake I made on that was NOT to leave an air gap.

Dave - I had a feeling someone would say something like this. Not that I am against, but I don't know if I am willing to drop my ceiling down any more than it already is. I only have 84" to the joists right now as it is. And lets face it, not like I have to put up with the noise:D

I was hoping for an E-Z fix on this one, but had a good feeling it didnt' exist.

[Al Willits]

HT or audio forums are prob the best place to go, maybe start at this one, lots of info there if ya do a search too

forums.soundandvision.com

Al

[Dave Buffington]

Jsut remember there is a curve, stuffing the joists with insulation will certianly help. Putting a ceiling under there will as well. Not as much as the full deal but it will be better.
Here is something that helps explain the mechaincs of acoustic treatment, it is based around tuning a room for music more than soundsproofing,. but the same logic applies:
http://ethanwiner.com/acoustics.html

[glenn bradley]

Dave hits on something worth noting. Is it the whining scream of the router (diffracting dampening like fluffy Fiberglas) or the low frequency rumble of the DC (bass traps and air spaces as mentioned) that is disturbing. If it is one end or the other of the frequency spectrum, you can focus your damping effort. If it's just noise in general you'll have a bit more work to do.

[Paul Johnstone]

I see you have metal duct work. That carries noise real well (in my unscientifc observations). My old house had the fiberglass ductwork and the noise transmission was considerably less than my current house with metal ductwork. I can hear the basement radio playing on my second floor through the ductwork.

[Mandell Mann]

If I'm not mistaking I think you can buy sound proof drop ceiling panels and replace the old ones. Check out a commercial ceiling dealers.:cool:

[Joe Branch]

I recently discovered that carpet and the padding below it can make a big difference over a hardwood floor. I removed mine in the living/dining room, about 30 by 20 ft. The basements sounds, even the background music, can now be easily heard upstairs.

[Steve Milito]

You need to do a "room in a room" to really cut down on transfer. You would need to run new ceiling joists between the floor joists, and frame the walls. If the walls are shared you should use 6" bottom and top plates and stagger 2x4 studs so that the dry wall is screwed to different studs. You fill all the cavities with acoustic insulation. You should not share HVAC. Dry wall needs to be glued and screwed. You ned to caulk all the seams with acoustic caulk, then add a second layer of dry wall with different seams. The goal is to completely de-couple all the room boundries. :D

[Eric Shields]

Chris,

Your basement looks at about the same stage as mine (http://www.sawmillcreek.org/showthread.php?t=31716) did last year, painted and empty. I too am converting most of the unfinished space into a workshop. Though I am still framing the walls, I continue to look for info on sound reduction, the internet is a wonderful resource. Unfortunately I'm at work and don't have my "shop resources" book of knowledge I have collected. However, one thing that has not been mentioned above is using Resilient Channel between your joists and drywall ceiling. JayStPeter has an informative post on his basement (http://www.sawmillcreek.org/showthread.php?t=10597) converstion, look at post #4 for the soundproofing.

Good luck, have fun, and keep us posted.

Eric

[Al Willits]

HVAC uses a compressed fiberglass to cover ductwork and reduce sound. foil backed and comes in different thickness's, might look at that for the ductwork, may help up in the joists too.

Al

[Brad Townsend]

When I built our house thirteen years ago, I insulated the basement ceiling just for soundproofing by putting batts between the joists. It wasn't for a shop, but for noisy teenagers!:D It has worked amazingly well.

[John Gornall]

Have a look at "Quietrock" drywall. I have seen one installation and it was quite amazing. It's supposed to be equal to 8 sheets of standard drywall - it's 5/8th thick.

I will be using it for my new shop later this year.