I'm making a door for a sound booth out of pine 2x4's and drywall that's going to be about 44 1/2" wide, about 78" tall, 4 1/2" deep. The depth includes 3 1/2" for the 2x4's and 1/2" drywall on each side.
Along with the frame of the door will be a couple of internal support members and R-13 insulation. So, it's going to be fairly hefty. My seat of the pants guess is it will weigh around around 80 - 100 lbs. give or take.
In selecting hinges, should a 3-pack of 3.5" hinges from Home Depot do the job?
I don't think the hinges are going to be the weak spot. 3 should be fine. Be sure you use hefty screws and be sure you know how the door carries the stresses..
Can you elaborate on this point? My plan is to use other doors in the house as a model, with the outer hinges a few inches in from the top and bottom and the center hinge equidistant between them.
The only thing holding the door square and plumb is the drywall. You should have a diagonal from the top of the hinge side to the opposite loiwer corner. The other question is warping across the surface. Even a light hollow core door will have a lot wider rails and stles than your 2x4s on edge. Gluing the drywall in will make a stiffer box
The hinges will be fine for a door of that weight and size as long as they're mortised into both the door and frame.
Why do you want to use drywall for the door? I realize that you're looking for sound deadening properties, but I don't know about the durability of drywall on a door. What are you going to use for the latchset?
Exterior doors, solid core are always 4 inch hinges and 3 of them per door.
I suggest that you find the local used door store and get a couple 3 solid core doors and screw them together instead of the drywall, which will not last very long.
Seems an odd design for a sound deadening door. Drop the insulation. Get a regular door and glue the sound insulating cones on it. I have been in sound chambers at work and this is how they do it. Of course if you are carrying on a ruckus you could damage the cones... from what I hear thermal insulation is not very good at sound insulation at all.
If I'm following what you're saying, either you misunderstood my description or I didn't describe it well enough.
The 2x4's are all going to be joined along their widest part oriented front to back- making the depth (thickness front to back) of the frame without the drywall 3 1/2", 4 1/2" after adding drywall on both sides, which is the same thickness as the rest of the booth - i.e., this will be like a section of the front wall of the booth, except it will be on hinges.
To further elaborate, I'll have two 12-3" screws at each point where the frame members join. A 44 1/2" piece across the top and bottom, with three
78" pieces between them vertically - one on each side and one in the center. The drywall will be screwed into the edges of all of these. For added rigidity and support I figured I'd add at least one diagonal member with the ends cut at 45 deg. to put on the inside of the frame at the upper right corner on the same side as the hinges.
In reality, I'll probably shorten all these dimensions by about 1/8" just to allow a small gap all around, with stops mounted on the inside frame of the box. I plan to hold the door closed with magnets mounted flush at strategic points on either the outer edge of the door or the stops along with a strip of metal mounted on the opposite side from the magnets.
I'll be picking the straightest pieces of lumber on and around the door area and shaving off just a tad with a table saw to make it as close to a perfectly mated area as possible. All the cuts on the 2x4's have been made with a miter saw and are all accurate to probably within half the width of mechanical pencil lead diameter of each other.
Thought I'd add I'm pre-drilling the holes with a drill press (using a homemade guide on the ends of the 2x4's) with a bit that's about the same size as the inner shaft of the screws (not the screw planes themselves) to avoid splitting the wood.
Exactly that, sound deadening properties to match the rest of the booth. This will be basically a "room within a room". If all goes as planned, the drywall shouldn't be taking any of the structural stress of the door. The plan is to make the frame very rigid and for the drywall to act strictly as a sound barrier along with the insulation laid inside.
To keep the door closed I'll use flush-mounted magnets and strips of sheet steel, which will be epoxied into an exposed area on the inside of the door frame and a stop edge mounted on the inside frame of the booth. Figured I'd use a router to cut the slots for both items, or maybe a boring bit if I use round magnets. All I need it to do is keep the door shut, no need for it to lock. I want to be able to push/pull it open easily when entering/exiting.
Sounds like a cool project but I do not know about the drywall. You will be mounting steel strips to the inside of the door, getting them flush mounted and having them look nice will be a task. I am sure the dges of your drywall will get damaged over time. Are you using drywall on the edges also, mainly the edge opposite the hinged edge? How you planning on creating a smooth transition between the drywall and 2x4 edge?
Your design is going to be more of a problem than I think you realize. There are all sorts of problems with it:
- door swing clearance on a 4.5" thick door. What sort of gap is required and how does that affect the sound transmission?
- regardless of what 2x4s you use, they're not furniture woods, and always have a bit of twist or warping in them. At almost 4' wide even a little twist will leave a gap, and even a little gap lets through a _lot_ of sound. My acoustics professor would tell us that acoustically speaking an 1/8" gap at a door is essentially the same as leaving the door open.
- the more I think about it, the less confident I am about my earlier advice about the hinges with a door that size. It's the width of the door that is the biggest factor, not the weight. I think I'd go with two pair of hinges to be on the safe side.
- drywall on a door is not a good idea. The surface is not hard enough to stand up to the abuse a door takes. If you want to tiptoe through the door every time you use it, it might be okay, but people push doors open with their hips when their hands are full and the facing paper will tear. I don't think it will be too long before the door looks old before it's time.
I'm not sure how critical your soundproofing requirements are, but a standard arrangement is to have two doors with one hung on either side of the wall. The separation is at least as important as the doors themselves.
Why don't you tell us what the application is and what the room will be used for? The door is an oddball size, as is your intended construction. Maybe we are looking at this the wrong way.
I wondered about that. Looking at a door that's about 1 3/8" thick, watching the gap between the door and frame, focusing on the corner which butts up against the frame (which is the part that matters) the approximately 2/16" gap actually seems to be overkill. If I take a wooden mixing stick that's just a gnat's hair narrower than the gap and open the door, there's no contact with the stick. Cearly the geometry is such that this edge never gets any closer to the door frame while it's being opened.
I think I just have to make sure the placement of the hinges creates a similar geometry on the sound booth door. Should be simple enough to work out using an overhead view paper model of the structures involved. Shortened of course, it doesn't actually have to be as wide as the door is. That inner edge of the door is either going to get closer or it isn't, doesn't matter how much of its length I look at. The drywall on the inside won't be an issue since it will already be cut back a bit to accomodate the magnets.
Anyway, as far as sound transmission, I can use gasketing in the gap that the door will have to brush against or and/or an exterior flap that fits flush against the exterior when the door is shut, plus the flush-fit interior door stop will act as a sound barrier.
Hopefully "machining" the edges with the table saw to get them very flat/square and making all the end cuts as exact/identical as possible with the miter saw will reduce this significantly.
10-4.
The drywall shouldn't take any abuse. I should have mentioned that it's likely only going to be me that will be using this sound booth. I'll have handles installed inside/out. I don't run a commercial studio. Just a hobbyist fooling around.
Well, my "second door" is the existing door of the room, which is itself already inside a house. Ultimately, I just want to cut down on the low frequency noise that comes in. It's actually not bad now, but I want to make it better. Some sound booth schemes call for more elaborate measures, more drywall, bigger gap, "floating" floor, but I believe they're going on the assumption that you've got a studio that's in the middle of a city - so even if an ambulance goes by outside or someone fires up a jackhammer, it won't be heard within the studio. I'm in a quiet suburban area, and what low freq noise I get is mostly from distant traffic.
Keep in mind, when I talk about "noise", for the most part it's nothing you could hear with just your unaided ears, unless a plane goes by overhead or something. If you sat in the room now in the dead of night, you'd consider it absolutely silent. But when the mic preamp is cranked to record acoustic guitar, there is low freq rumble that registers on the VU meters of the recording software and can be heard on the monitors when A/B comparing it to no input from the mics. I'd be happy if I could subtract another 10 - 15db or so from the noise floor, which I think is possible (hopefully). Of course, I'll be treating the interior of this booth as well to deal with sound reflection within the booth itself.
There's one window in the room, for which I made a "plug" out of acoustic paneling, lumber and foam. That alone cut down the noise so much (probably by over half), it gave me the idea that this booth would for all intents and purposes given my surroundings, give me a totally silent area so that the only noise would be the electrical noise of the signal chain - mics, preamp and system (no system is completely noise free). The computer I use is in a separate room and is essentially a non-issue given the way it's situated.
See above.
I decided I wanted it big for a couple of reasons - It will give me elbow room for moving mic booms, guitar, music stand etc. in/out without banging things and I'll be able to mount the outer edge stop using the 2x4 that will already be supporting the other sheets of drywall that will comprise the rest of that wall.
Do you care more to keep sound from excaping the chamber, or that you eliminate reflections within the chamber, or keep sound from entering the chamber, or some combination of these?
If you make the door bigger than the doorway, you can set it up so that it closes up against the wall, compressing foam/felt/rubber gaskets as it does so. That way you don't have to worry about fit. If you want the door to open more than 90 degrees, you'll have to use offset hinges like these: Mounted to a 2x4 screwed to the face of the wall.
Were I doing this, I'd make the door out of 1/4" ply, with sheetrock glued to the inside of the plywood sheet. Either use different thicknesses of sheetrock, or do something to change the weight or stiffness of ONE of the two panels, so they don't ring each other. I'm told that a layer of asphalt roll-roofing works well for that.
How are you handling ventilation? It'd sort of suck to have a totally soundproof room that you have to leave the door open on, else you suffocate.
As per my previous post, my primary reason for the booth is blocking out or at least significantly reducing a small amount of low frequency rumble that's getting in. You're always going to treat the interior of your recording area regardless of its size to deal with reflections between parallel surfaces. This shouldn't be too complex since all I'll be dealing with will be acoustic 6-string, possibly trumpet and vocals. (One at at time)
Noise getting out isn't a consideration given my circumstances, not trying to isolate for example, a drum set from other recording rooms etc.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.