Now that you’ve got your designated studio space, your first order of business is framing out the walls. If you consult a standard construction manual, you’ll find that a typical wall consists entirely of 2’ x 4’ studding - a top and bottom “plate,” held together with vertical studs fastened every 16” (or “16 on center”). When it comes to framing a studio wall, however, there are several significant differences. Instead of using 2’ x 4’ studs on a 2’ x 4’ plate, you’ll be putting 2’ x 3’ studs on a 2’ x 4’ plate, one every 12” with every other one situated at the opposite side of the plate. The finished product might look like it was designed by Curly and Moe Howard; nevertheless, the so-called “staggered-stud” frame inhibits sound transmissions by keeping the interior and exterior walls separated (since they’re not fastened at the same stud).
You could simply attach the top plate to the floor joist; however, an even better method would be to “suspend” the plate using brackets and insulated spacers to prevent sound from moving directly through the top plate into the main structure of the house. Similarly, you don’t really want to have the bottom plate touching the concrete floor of the basement; instead, keep the two separated by placing a layer of sill foam directly under the plate.
The point is simple: Whenever possible, try to avoid having any part of your room come in direct contact with the existing framework (hence the theory of building a “room within a room”). This method of building requires a bit more forethought, but if done properly it will help keep your subterranean noisemaking from reaching unauthorized personnel upstairs.
One other point: Assuming you’re doing a double room, you’ll need to include the frame for the studio glass at the appropriate height on the adjoining wall. Make a frame that allows for as much space as possible between the two sheets of glass. (Note: While having a window in place is the most logical choice, a simple video cam and monitor would also do the trick.)
Walls and Switches
Covering the interior walls/ceiling. Start by putting up the walls - take your time and measure properly. You’ll want to keep the seams to a minimum (in order to cut down on the potential for sound leakage), so wherever possible fasten the sheets of Homasote as a single piece (which is a little more challenging than separating the sheets into moveable smaller pieces, but it’ll look and sound a whole lot better). Don’t go overboard on the fasteners (a slightly loose fit is okay - you don’t want a totally tight wall), and try not to drill the screwheads below the surface of the board.
The ceiling requires a bit more maintenance. First, stuff the joists using rolls of fiberglass insulation (don’t settle for anything less than papered insulation, a.k.a. “craft-faced,” and make sure you’ve got eye- and mouth-protection as well). Since my basement has 9’ceilings, I choose not to do a resilient channel just yet, figuring I could always add it on to the existing ceiling at a later date if need be and still have more than enough headroom. Nevertheless, I tried to incorporate some of the resilient-channel methodology by using spacers and rubber grommets to attach the sheets of Homasote to the floor joists (allowing some degree of separation between the two surfaces).
If you’re going at it alone, this can be a particularly gruesome operation, since you’ll need to hold a separator in place on the top side of the Homasote while inserting a 2” fastener through the other side. I found it necessary to abandon the no-cutting rule and slice the Homasote into pieces small enough to hold overhead using a pair of stepladders (incidentally, a drywall lifter, available at your local rent-a-center, is perfect for this job and subsequent drywalling applications).
Juice boxes. Before you begin walling up the other side, you’ll need to bring some electricity into your rooms. (Be aware that making alterations to domestic electrical installations is highly regulated in some states and may even be illegal - check with the authorities before you start wiring.) Two outlet boxes per room was enough for me, and I simply ran a few quality outlet strips off each one for extra plugging capability. The best way to work in the outlet boxes is to measure and make cuts in the Homasote before you put it up. If you have an existing line in your basement for lights without any heavy machinery attached to it, all that is needed is a junction box and a good length of 14/2 WG or 12/2 WG grounded connecting wire, making sure that all wires are properly fastened to the outside studs using insulated staples and all connections sealed tight. If you hire someone to do your wiring (and if you’ve never done this kind of work before you probably should), be sure to tell the electrician to flush-mount all the boxes so that there are no gaps between the outlet cover and the wall.
While we’re talking about wires, now’s the time to bring your XLR and any other audio cables you’ll be using from the recording room through the wall into the control room. You can use a snake (a plastic tube grouping all the cables together); I simply cut a hole through the wall and ran the wires through, sealing each side good and tight. When doing this job, don’t line up the interior and exterior holes; make one slightly above or below the other (so sound can’t pass straight through). Run at least one instrument cable between the two rooms, which will allow you to plug directly into a nice loud amp from the sanctity of your nice quiet mixing console later on.
Let’s rock. After filling in between the studs with insulation, it’s time for some drywalling. Though more cumbersome than Homasote, half-inch drywall slices up relatively easy. One important thing to remember before you begin cutting: Try to avoid having the seams from the inside Homasote match the seams of the outside drywall. For instance, if you installed the Homasote vertically, you’ll want to hang the drywall horizontally. That way, any sound that happens to pass through a Homasote seam won’t have a chance to escape through a parallel gap in the drywall as well. (Now you can really see the wisdom of that staggered-stud wall!) Also, try not to let the pieces of drywall touch the outside basement floor or sit flush up against an exposed floor joist. Use some of the sill foam at the top or along the bottom, if you so choose.
The end result should be a wall that is a sandwich of different materials, with drywall on the outside, followed by fiberglass insulation, followed by Homasote on the inside. Once you’re done hanging both interior and exterior walls, you can decide whether or not you want to spring for some shiplap pine. One look inside a friend’s pine-covered studio was enough to convince me (though I only bought enough wood to do the control room for the time being, in order to keep the cost down). If you do add pine to your room(s), make sure to install the boards with the rough side facing out in order to minimize possible sound reflections (wear gloves, though - they’re splintery buggers). Start by fastening some furring strips across the face of the Homasote wall at the rate of one long strip every 2’ or so. Attach the pine directly into the furring strips, making sure that each board fits snugly together in order to avoid sound leakage. Also, try to keep the corners rounded wherever two walls intersect - just angle a board slightly before it meets the adjoining wall (though you’ll probably have to add another shim behind it first).
Installing the Glass; Hanging the Doors
Whenever I start bragging to my friends about this basement studio I built by myself, I conveniently leave out the part about the studio glass. Let’s face it: Two 8� long sections of 3/8” window that would smash into a million sparkly shards if you made one false move is not a job you do alone. For one day, I called out for a pair of competent helpers.
I was fortunate enough to receive a sealed, double-glazed window unit as a gift, but even if you have to buy one yourself, all you really need is the glass used in an everyday household sliding door (which is where my glass actually came from). It’s not terribly expensive stuff - your best bet for a bargain may be the local building-supply salvage retailer. If possible, see if you can get a panel with two panes of unequal thickness (yet another page from the disparate materials manual). Once you set the glass in the frame, it’s fairly smooth sailing. Incidentally, by slightly slanting the window you’ll cut down on light glare and increase visibility between the two rooms (something I forgot to do, but I can live with it). Just be sure to leave a bit of an air pocket between the two layers - and then caulk the bejesus out of it. Leave no crack unsealed! Carefully frame around the outside of the window, and add strips of cork around the seal of the glass for a final layer of sound protection.
Your friend, the cheap pre-hung metal door. After all the time and energy spent sealing up gaps around the walls, ceilings and window, the thought of losing it all through a pair of incompetently hung doors had me in a cold sweat. However, this job turned out to be a breeze (relatively speaking) thanks to the existence of the cheap and, coincidentally, sound-efficient pre-hung metal door ($100). Not only do they eliminate the need for an actual doorframe (an odds-on train wreck for the likes of me), their form-fitting seal makes them surprisingly well-insulated. You just have to build a rough opening, then make sure your door is level before fastening it to the frame.
Here’s Mud in Your Eye
Wouldn’t you know it that the most important part of the job gets saved for last. Here’s where you get to go through the rooms with a fine-toothed comb - and a big bucket o’ mud (joint compound). Carefully tape up all your drywall joints, smear on the filler, hitting up any obvious gaps, etc. Allow a good 24 hours for the mud to dry, touch up, sand, and prime white. For the Homasote-covered interior, apply a modest amount of expanding insulating foam into all ceiling and wall joints (unless you’ve already covered the wall with pine), wiping away the excess foam each time so that the foam dries flush with the surface.
Go back through the room and plug any obvious gaps, making sure that the doors seal properly and the studio glass offers enough sound separation between the two rooms. Then during the evening hours, turn on all the lights in the outside basement, go into the darkened studio with the doors closed and inspect for any light that may be seeping through. Cover even the most seemingly innocent holes using a combination of weather stripping, caulking, or even bits of discarded Homasote.
Take Time for Tweaking
Well, it sure looks purty from the outside - but looks don’t matter much if it sounds like crap from the inside. Hence, the part I was dreading the most: getting all the instruments and gear back into the rooms and cranking everything up. However, don’t be alarmed if, indeed, it really does sound like crap at first. There’s still plenty of tweaking you can do in advance.
Cut the rug. For decent sound absorption (and to give the rooms a professional appearance), go with premium grade indoor-outdoor carpeting over a quality carpet pad (made from fiber, not foam). As I mentioned earlier, I spent a fair amount of time lurking around the remnant bin at Home Depot and eventually found what I needed, and for a very good price. Carpet installation is another relatively easy DIY job; just draw a template of your floor, unroll the carpet in a large space outside the room, then make the appropriate cuts using good shears or a straight-edge and haul the finished roll into the room.
Auralex - the reflection eliminator. After you’ve got the carpet laid, walk around the room and test for additional unwanted reflections. In my case, there was a significant “bounce” coming off that plywood enclosure I’d made for the control-room ceiling. To remedy the problem, one of my pals provided me with a few generous slabs of Auralex acoustical foam, which I stapled to the underside of the enclosure (and on portions of the walls as well). Presto - no more echo. Though less attractive than Auralex, a portable foam mattress cut to size will also do the job, and is significantly cheaper. While you’re at it, apply some padding to the inside of the metal studio door using a decent adhesive (or even duct tape).
Done and Done
Once you’re reasonably sure everything’s sealed up, damped down, painted, sanded, and spackled (or anything else that requires making more mess), put the room back together and start sound experimenting. For the recording room, get someone on the drum kit or plugged into a guitar or bass amp, close both doors, go upstairs and listen to the results. The toughest test will be the room that sits directly overhead; rooms that are situated opposite the studio will have significantly less exposure to the sound frequencies. If you’re not yet satisfied with the results (too much bass bleed-through, unwanted vibrations, etc), try moving the drums into a different corner, hanging a tapestry from the ceiling or on an opposite wall, putting an amp up on a small milk crate, placing an open box directly in front of a bass amp or bass drum which will act as a ‘bass trap’ for low-frequency leakage, and so on.
The control-room soundproofing test is simple: Put on some AC/DC, go outside, and check for leaks. Better yet, put on some AC/DC, open a beer, and wait to see if the neighbors call (then check for leaks).
(For more tips on classic tools and techniques, check out Dave Simons’ new book, “Analog Recording: Using Analog Gear in Today’s Home Studio,” from Backbeat Books)