Here's what I've got... Can you help me make it better?

So here's what we have: A roughly 15' 5" by 8' room, eight foot ceilings 5 1/2" thick staggered stud walls with Ultratouch insulation one layer of drywall on the walls Quietrock on the ceiling solid wood door with weatherstripping. I've seamed all the seams inside the room (not on the outside, should I?) with acoustic caulking. I'm guessing the contractor didn't use any acoustic caulking on the studs, since he thought I was crazy when I told him I wanted to caulk the seams of the drywall with it. I want to use this room as a rehearsal space for our (rather loud) band. To test it out I put a very small ipod boombox in there and turned it up as loud as it could go (which, compared to most boombox's wasn't very loud). I couldn't hear much, but I could still hear it a little, and considering that my band is waaaaaayyyy louder than an ipod speaker doohickey, I doubt it's soundproofed enough for what we need. So my question is, what are some of the (cheapest) ways to get this thing good enough for my band? I'm planning on getting some green glue and putting up another layer of drywall, but do you think that will be enough? Is there anything else I should consider? Thanks!

Hi Adam. Welcome. There is an announcement at the top of the forum about what to do to assure getting as many responses as possible. The announcement leads to this post (click here). Actually, several people, who are experts on this forum, will not reply if you don't do what is written in that post. Many others who are very helpful, will not reply out of respect for the moderators' wishes. Anyway, quick answers:

A roughly 15' 5" by 8' room, eight foot ceilings

That's a bad start! Your room has a square profile. 8' high by 8' wide. So the ratio is 1 : 1 : 1.92, which is about as bad as you can get. All your room modes line up exactly, or are real close to lining up exactly. You'll have huge resonance issues with that room in the low end. You really need to do something about the dimensions to get them close to a good ratio, or at least to get them away from such a terrible ratio.

5 1/2" thick staggered stud walls with Ultratouch insulation one layer of drywall on the walls. Quietrock on the ceiling

That's better than nothing, but it won't give you good isolation at all. Your STC like that will probably only be in the mid 30's, and you probably need something more like 60 - 65, based on what you say.

solid wood door with weatherstripping.

Solid core door is good. Weather stripping is good. But still not enough. To get the kind of isolation you are talking about, you need two back-to-back solid core doors, perhaps beefed up with additional mass on each, and at least two full seals around each door.

To test it out I put a very small ipod boombox in there and turned it up as loud as it could go (which, compared to most boombox's wasn't very loud). I couldn't hear much, but I could still hear it a little, and considering that my band is waaaaaayyyy louder than an ipod speaker doohickey, I doubt it's soundproofed enough for what we need.

That's an understatement! An iPod thingy is not going to put out much energy at all, especially in the low end, and the low end is where you will have the worst problems. So if you can hear your iPod thingy so easily, you don't have anywhere near enough isolation. You didn't mention the floor: What is the floor made of? Please say it is a thick concrete slab on grade!!! Please don't say it is a raised wooden deck!!!

So my question is, what are some of the (cheapest) ways to get this thing good enough for my band?

Pick one or the other! You can't have both. You can have "cheap" or you can have "good enough for my band", but only one of the two.... .)

I'm planning on getting some green glue and putting up another layer of drywall, but do you think that will be enough?

Frankly, no. You don't have enough mass in the walls and ceiling, and they are not decoupled, so GG is not going to do much for you. It will do something, but it won't get you where you want to go. Basically for good isolation you need to build a decoupled and isolated "room within a room" system, with a two-leaf wall all around you, including the ceiling. That means a normal double stud wall (two sets of studs) with 2 or 3 layers of normal gypsum board (="sheetrock", ="plasterboard", ="drywall") only on the outsides of the studs, green glue between the layers of gypsum board, with the air gap between the leaves packed full of fiberglass or mineral wool insulation, and everything sealed up hermetically. This will give you the "mass-spring-mass" principle that is the best way to achieve good isolation at low cost. The gypsum board layers on the outside of your fist stud frame is the first "mass", the air gap plus insulation is the "spring", and the gypsum board layers on the outside of the other stud frame is your second "mass". It has to be sealed hermetically to work properly, but if you do it right, you can achieve excellent isolation. There are many variations, and many ways of accomplishing this. Use the "search" feature of this forum and you will find them all. What you probably need to do is to take off all of the drywall in that room, use what you take off to beef up the OTHER side of the wall from inside it, in between the studs, seal it up carefully. Then build your second frame several inches away from the first, absolutely NOT touching the first frame OR the ceiling. Pack the gap between frames with insulation, and put up a couple of layers of 5/8 drywall on only one side of that frame, using Green Glue between the layers. Seal it airtight. Now build your inner leaf ceiling resting ONLY on the new inner leaf wall that you just built. Same thing: fill the gap between old ceiling and new ceiling with insulation, a couple of layers of 5/8 drywall, seal it airtight. Now you can think about acoustic treatment to make the room sound good for your band. It will sound terrible if you just leave it as is. And you also have to think about HVAC. Putting a bunch of people, instruments and equipment in a small airtight room for long periods of time is not good for your health! People have a habit called "breathing", and they can't do without it for very long, so you need to bring in fresh air through a series of silencer boxes and acoustically lined ducts, and you need to exhaust the stale air through another series of silencer boxes and acoustically lined ducts. That will get you where you want to go. - Stuart -

Thanks for your response, I've seen posts on this forum before and so in a rush decided to sign up, but didn't look over all the rules first. :oops: I'm not 100% sure what I'm leaving out in order to get people to respond, so I'll try to cover what i think is missing... I'm in Oakland, California. My budget at this point is only about $300-400, but if it's something that won't be over say 800, there's the possibility that I could save and do it a few months down the line (my fiance and I are also trying to save for our wedding, hence the shortage of money), or even if it's nothing extremely extravagant, it's something I could plan on for the future. Tearing down the room and starting over isn't really an option. I could possibly convince them to let me tear out the current drywall on the inside of the room, but definitely not anything on the outside or any of the framing. I was lucky enough to convince her to get what is currently there. The floor is a solid slab of concrete on grade, I think he said it was 4 inches thick on top of sand and then gravel. I don't have an SPL meter as of yet, so it's impossible for me to say what exact volume we are, but we're a rock band with 2 electric guitars, electric bass, keyboards, vocals and drums (if any of that helps). I'm sure it doesn't need to be 100% silent from the outside, but quiet enough to not have the cops called. The garage was recently built, so I might be able to track down the plans if that would help. As you've stated, the dimensions of the room are terrible, I plan on doing a lot of acoustical treatments later down the line to deaden the reverberations, but unfortunately, as it is, it's going to be a tight fit, so I don't think shrinking the space any for acoustic properties would be the best idea, since our six piece band would probably barely fit in it as it currently is. I'm not really looking for a great sounding room so much as just something that my band can rehearse in instead of our $600 a month practice space.

I had them quickly e-mail me the plans. From what I can tell there were some small aesthetic changes and the electrical box was moved to the inside of the front room but I think this should suffice for giving you a good representation of what I'm working with. Let me know if any other parts of the plans, or if any close-ups of anything would help. Thanks for any help!

"but I could still hear it a little" Where were you at when doing this listening...close to a door, window, outside? Either of these places may be exposing the weak areas of your build, like windows needing a massed up plug in, doors needing better sealing and the potential for sound to escape thru what may or may not be Quietrock on the ceiling. The print reads that the building would have 5/8 inch plywood on the walls. Do you know if it has the 5/8 inch plywood plus 5/8 inch sheetrock, or is it just sheetrock? This would make a difference as well. What kind of exterior facade is on the building, metal, vinyl, brick, rocks? Your final layer of rock (interior) should be taped and floated with typical sheetrock mud.