sound blocking not proofing

[rcktdg]

I have finally been able to realize a nice space at a decent rate in an industrially zoned area. It is fairly large @ 1100 sq. ft. with 9'6" ceilings at the bottom of the 12 joists.

My problem is that the north wall borders a residential area. The wall is about 3'6" below grade (concrete block) with 2x6 studs stucco outside and drywall inside with no insulation between above grade. The east wall is solid concrete block. The west wall is wharehouse space filled with all sorts of clay poats and such. The south wall has an aluminum single panel garage door with a 30" door inset and has a huge wharehouse across from it.

The place is vacant at night and my band want to use it to rehearse during the evenings. The space is pretty big but not too big. I cannot afford to soundproof the whole thing and I do not want to partition it into a tiny space. I am tired of being crammed into a 12x12 room. I want to block the sound from going though the north wall.

Is is possible to block sound in a particular direction or do I have to soundproof the whole thing? I am building a U shaped wall within the room. Is this a wast of time? It is metal frame 24" center floor to ceiling 5/8" drywall about 6" away from the existing walls. Do I need to install insulation? Am I doing anything to accolplish my goal. I am not ruling out drywalling the ceiling but presently I would like avoid it for many reasons. Is standard insulation a waste of time for dampening sound. I have read many sites but they are all about acoustic treatment or soundproofing. The really don't acknowlege just blocking it in a particular direction.

Thanks,
RD

 

[Alex W]

The short answer is no -- you can't block sound from only one direction completely. The problem is known as "flanking", which means the sound waves will just dodge around to the areas that aren't blocked and get through anyway.

My question would be do you really need to soundproof that much? My band used to rehearse in a warehouse at night and didn't have any problems. Have you tried playing there and gotten complaints?

Alex

 

[rcktdg]

Not yet...

A complaint is a wound that never heals. One complaint and lterally thousands of dollars of fixes will likely be insufficient after the fact. I want to avoid having any, ever.

I am coming from a life where at one point playing accoustic guitar after 10pm in the summer with the windows open was unacceptable to a neighbor no matter what. I am a professional guitar player and have been for 16 of my 22 years of playing so I like to think it was actually pretty decent sounding stuff. They wouldn't call the cops, they knew my landlord and they called her.

Currently, I am relocating to this space because of an intolerant neighbor of our old space that says we must quit at 9pm. Once again we play at a respectful volume and never get any complaints other than this guy. We work twice a week from 7:30 to 9 pm. One minute past 9 and at 9:40 the cops show up while we are discussing parts or future gigs, etc.

It feels rediculous to be at this point in my carreer and still be treated like I am a 16 year old punk. Unfortunately the only option is to let this guy win because I would rather put my money into a space than into a lawyers pocket trying to fight him in civil court where he will likely win. In the rare case where I prevailed I would only gain an hour at the most. I would rather work 8-11 anyhow because I teach until 7 and racing to start a 7:30 is a pain.

Since I have been in this for so many years I have decided to treat myself like the professional that I am and get my own place and concentrate all my operations there.

The situation is pretty fluid at the moment because the interior framing is 99 percent complete and insulation and drywall will follow shortly. We talked to a soundproofing guy and I got the bid today. $3390 for installed insulation and duct wrap or something like that. My only complaint is that it is happening as quickly as it needs to happen but I am too busy to keep up like I would prefer.

I might try to post some photos at some point.

Geez, long post. I guess I needed to vent.
Cheers, RD

 

[Alex W]

I understand. Post some pictures as well as additional construction details from your contractor and we can try help out.

From a total isolation perspective--nothing beats the room-within-a-room.

Good Luck,

Alex

 

[rcktdg]

Realistic Expectations

I am getting some photos together as I type but on a slightly different subject I do not expect the impossible. While I said I would like to block the sound I understand that it is impossible to block it in one direction but not in another. I would like to greatly reduce the volume of the sound in a particular direction by making it indirect, reflected sound. Hopefully this will make things less detectable from inside one of the nearby apartments.

It is an industrial area but it is generally quiet at night. I will likely be the only thing going after 7 or 8 pm.

Pictures to follow...

RD

 

[rcktdg]

it wont let me attach the files, it says it's too big at least it's not too loud

I will try again later...

 

[rcktdg]

Before

This is the area where we will go about our business.

To describe the room...
East wall is 37 ft long by 9' 7" (Concrete block)
West wall is 31 ft long by 10' 10 (1/2" drywall & r13 insul)
North and south walls are 29' (N wall partially below grade, S wall 1/2" drywall and insul)
South wall is square to east and west walls.
South wall aslo has 7' garage door.

The photo is looking into the north east corner. This is also the direction of the residential area.

 

[rcktdg]

Currently...

Currently we have metal studs to the rafters and have blocked in the voids between the ceiling joists and the header beam supporting them. Outside the frame of the photo is a 9x12 patition separating the garge door from the rest of the space with a 36" insulated metal door to allow passage in and out of the main area.

I have made a few decisions regarding how I will proceed. The sound proofing guy who gave the $3400 bid for insulation and duct liner was basically a finished product option. Meaning that if it was not sufficient in reducing the volume to the outside world I was kind of stuck. The duct liner is applied with mastic and it would make removing it to add other means of reduction nearly impossible. The plan was to cover everthing.

I have decided to go for better mechanical isolation because I fear this is my greatest enemy. I will preface this with the fact that I cannot afford the entire room within a room structure. I have future plans for the space that require it to be large and open.

Here is my plan:
1.) I purchased enough RC-1 to cover the entire room, walls and ceiling.
2.) Tonight I will get the r19 insulation to cover the wall that I constructed and to cover the entire ceiling.
3.) I will apply rc-1 to the metal studs and to ceiling.
3.1 I am strongly considering hanging drywall on the ceiling over the area where we will set up (20x28) to reduce the volume coming though the roof at it's most intense point.
4.) Hang drywall to mounted rc-1 on the walls that I built.
Seal with liberal amount of flexable caulk.
5.) Say a prayer
6.) Put down a temporary rug and apply Drummer with kick drum.

My sound test is to call him with my mobile phone and have him strike the drum a few times in no particular pattern to see if I can hear it from the parking lot of the building I am concerned about. Pending it's success or failure I will move around the block and observe the volume from those positions too. I might even inculde the bass player in the noise if it goes well enough on the first go around.

I know this is primative but it is the least labor intensive way I can think of to find out what I have accomplished.

If I deem the test a failure my plan will be to cover the entire ceiling with drywall, test and then mount rc-1 and hang drywall in the rest of the room if needed. Eventually I will arrive at an acceptable solution. I do not expect the impossible but I do want to avoid any complaints. The combined cost of my incremental plan is much less than the quoted $3390.

Whew, it was quite a day of considerations.

Am I on a highway to hell or does this plan seem like a possible way to accomplish my goal.

Cheers, RD

 

[Tim Brown]

Another thing that you can try, is build some Gobos to put around the drummer. Make sure that they have an absorbant side that is facing the drumkit...and they don't have to be "right on the kit"...you could have them set a couple of feet out from the kit, but I would make them 4' High.

That would help keep the "direct" sound of the kick from just instantly expanding in the room... as there would be a soft surface just a couple of feet in front of it.



Tim

 

[rcktdg]

This crossed my mind

A friend who just finished sound proofing his garage and went the whole nine yards has offered some large scraps of Auralex foam that I thought would make a nice sound break like you described.

The framing is complete and things are moving along nicely Today we installed about 1/4 of the insulation. the rest of the week will be preparing for drywall. Everone is taking next weekend off and then full steam ahead to finish the drywall.

I think it is going to work out fine. I am excited that this time last week it was an empty room and it's already starting to take shape.

Cheers, RD

 

[Alex W]

RD,

Sounds like you're on the right track. If the isolation you achieve isn't sufficient with a single layer of drywall on your RC channel, I'd try adding another layer of sheetrock to the channel, rather than stripping it back to the studs as I think you described. Drywall/Channel/Drywall results in what is known as "three leaf construction" when coupled with your wall cavity and exterior building (either block or metal), and does funny things to your isolation. Suffice it to say you are better off adding more mass to your resilient wall, especially if you want to stop low frequencies.

Alex

 

[rcktdg]

Alex W,

As I understand RC it can hold up to 3 layers of drywall. My plan is to just add another layer of drywall on top of the first layer if I have too much sound getting to the outside world. While there is a lot of work associated with adding more drywall it seems like mass is the best thing I can do. Each layer will not only add mass but give the sound many more twists and turns to get to the outside.

I must admit I am starting to expect good results. I am trying to keep my enthusiasm in check. I can't believe that it has gone so far so quickly. I cannot wait to start testing the sound levels.

Thanks, RD

 

[Dan Merrill]

rcktdg

Allow me to play the devil's advocate and make a couple of observations:

1- Have you done a pre check with a kick drum to see what you're up against, and also to give you a way to gauge whether you've actually improved it once you've made some of these changes?

2- I personally question the soundproofing capabilites of merely using R19 insulation and resilent channeling with drywall when involving drum kits and band volumes. ( BTW, most recommend varying the thicknesses of the drywall when going with multiple layers) I've been in hotels with insulation and drywall and those walls aren't stopping much. I'm guessing of all the frequencies that you're attempting to "direct", the low end will be the least respectful- unfortunately the very one you hope to contain the most...

This page on Auralex's website shows some detail of how they do ceilings and walls. There's something to be said for mass.

http://www.acoustics101.com/room_itself_gateway.htm#The Room Itself

3. Also, have you considered that once you put drywall on those two walls and the ceiling, it's likely to become very loud inside the space itself and be in want of interior acoustic treatment to get it to sound good for rehearsing?


In spite of these negative observations, I do wish you well with the project!

 

[rcktdg]

There is more to the story than has been told

I respect your questions and regularly consider them as I stare at the ceiling each night trying to figure out if I am the biggest or even the second biggest idiot on the planet.

"1- Have you done a pre check with a kick drum to see what you're up against, and also to give you a way to gauge whether you've actually improved it once you've made some of these changes?"

No. Part of the reason is that it is obviously needing at least something to keep the sound in. There were openings all along the roof joists that would simply let too much airborne sound out to guage the structural containment. I have a little more blocking to do and I will do some light testing to measure the effectiveness of the structural isolation during the preceeding stages.

"2- I personally question the soundproofing capabilites of merely using R19 insulation and resilent channeling with drywall when involving drum kits and band volumes. ( BTW, most recommend varying the thicknesses of the drywall when going with multiple layers) I've been in hotels with insulation and drywall and those walls aren't stopping much. I'm guessing of all the frequencies that you're attempting to "direct", the low end will be the least respectful- unfortunately the very one you hope to contain the most..."

Yes, I question it too. I am thinking clamshell at first. Put something massive in front of something and the energy it takes to go around might be enough to difuse it sufficiently. If it does the job then great. If not, I keep adding mass to all the walls. Even better for me if the next layer can be 1/2 in. There is also a 4 to 6 inch air gap between the R19 and the existing structure.

The group I play with really is not very loud(subjective, I know). What I am trying to build might not work for a some but I am not trying to set any records with volume. My ears are my living.

"3. Also, have you considered that once you put drywall on those two walls and the ceiling, it's likely to become very loud inside the space itself and be in want of interior acoustic treatment to get it to sound good for rehearsing?"

When I decided drywall was going on the ceiling it occured to me that things could start to get rather noisy. The plan has always been very thickly padded carpet in the 20x28 area and I have enough heavy theater curtains to go half way around the room. Hopefully that and some furniture will make it reasonable.

There is risk that any engineering endeavor can fail despite the best intentions. I do not have the budget to gaurantee success. I do have a budget and I may throw it all away but what do I have if I don't take a chance? I have done some research. I have many many years of experience with music. I have an electronic and electromechanical engineering background to add to this. What does this mean to sound proofing? Not much. Can I fail? Yes. Adding to all of this is the fact that I am one of the luckiest people I know.

Cheers, RD

 

[Dan Merrill]

Re: There is more to the story than has been told

I
There is risk that any engineering endeavor can fail despite the best intentions. I do not have the budget to gaurantee success. I do have a budget and I may throw it all away but what do I have if I don't take a chance?
Cheers, RD

an excellent point. keep us posted!