Fig. 1. Acoustics First StratiQuilt (diamond-pattern quilt) seals off a window. It’s mated to the jamb with industrial velcro.
Nothing kills the vibe of a recording faster than extraneous sounds leaking into microphones from the surrounding neighborhood and adjacent control room. The rich man’s solution: Spend an arm and a leg (and weeks of your time) constructing a new ceiling, floor, and walls—all floating on neoprene—inside your existing tracking room (thereby creating a room inside a room). The pauper’s fix: Use affordable, off-the-shelf items to sow the sound of silence in one day.
Of course, there is no free lunch. The pauper’s fix—which I’ll detail in this article—won’t completely mute the roar of a jet flying directly over your abode or a lawnmower grazing on grass right outside your window. But for relatively little money, you can dramatically subdue the din of kids, cars, and Corky, your neighbor’s barking schnauzer. Your band will also be able to practice and record full bore without disturbing your ’hood. What’s more, these low-cost solutions require no permanent construction; they can all be easily reversed if you decide to move.
A hammer, screwdriver, and caulking gun are all the tools you’ll need. We’ll begin by bolstering the weakest link.
Seal Off the Windows Sound passes through objects by making them vibrate. Because the high rigidity and low mass of glass causes it to vibrate easily, sound waves pass through it much more readily than they do through heavy drywall. That’s why your tracking room’s windows are the most important areas to treat. Fortunately, Acoustics First Corporation (acousticsfirst.com) offers two inexpensive products you can use to impermanently seal off your window: ABF1 Composite Foam and SQ125 StratiQuilt Double-Faced Barrier Blanket.
ABF1 is constructed of acoustical foam bonded to both sides of a vinyl septum that’s roughly 1/8-inch thick. Available in different sizes, ABF1 is flexible enough that you can cram it into your window jamb, yet it’s rigid enough that it won’t fall down. The foam is 1-inch thick on ABF1’s inside face, the side that’s meant to face into your tracking room. The foam on the outside face is 1/4-inch thick; it faces your window and keeps window vibrations from causing the vinyl septum to vibrate and vice versa.
For little additional cost, you can order ABF1 with aluminized mylar bonded to the inside face; this configuration is dubbed ABF1-M. I suggest you flip ABF1-M around so that the mylar faces your window pane. This will help reflect high frequencies in the outside world away from your tracking room. With ABF1-M installed thus, the 1-inch foam becomes the acoustic decoupler between window and vinyl septum. The mylar’s slick surface also imposes a lot less drag than foam on a window pane, making it easier to slide ABF1-M into place.
Like ABF1 and ABF1-M, the SQ125 StratiQuilt also uses an internal vinyl sound barrier. But instead of foam, the vinyl septum is mated on both sides to fiberglass boasting a density of two pounds per cubic foot. The whole shebang is quilted and faced with vinyl on both sides to contain the fiberglass. Grommets along the top edge allow you to hang the SQ125 from nails or screws fastened above your window (just below the wall-ceiling seam; see Figure 1).
You’ll need to secure the sides and bottom of the SQ125 so that it provides a good seal around your window jamb. Buy a 2-inch-wide roll of adhesive-backed industrial velcro from Lowe’s or Home Depot. Apply the velcro hooks along the sides and bottom of the window jamb. Attach the velcro loops around the periphery of the SQ125 (on the side facing the window) so that it mates to the velcro hooks on the window jamb.
ABF1-M blocks sound far better in the bass region and far worse in the midrange band compared to the SQ125. For this reason, I use both in my tracking room’s window. The ABF1-M is placed in my window jamb, and the entire window (and the installed ABF1-M) is covered by the SQ125. The two products complement each other’s performance nicely and add more sound-deadening mass when used together.
Fortify Your Door and Walls If your tracking room has a hollow-core entry door, replace it with a solid-core door. A properly installed solid-core door—with adhesive-backed foam or felt weather-stripping applied around the jamb perimeter—is almost as effective at blocking sound as a single-layer gypsum wall. Be sure to install an automatic drop seal on the bottom of the door’s outside face (the side that’s outside the tracking room). Such a device lifts when the door is opened and drops down to cover the gap below the door when it’s closed.
For chump change, you can also upgrade the ability of your walls to block sound. Carefully pull off the molding at the bottom of each wall. Apply OSI Pro-Series SC-175 Acoustical Sound Latex Sealant with a caulking gun to fill the gap between the bottom of the drywall and the floor. SC-175 is permanently flexible and therefore resists vibration and sound transmission. Replace the molding, and enjoy the hush.
Michael Cooper is the owner of Michael Cooper Recording (myspace.com/michaelcooperrecording) and a contributing editor for Mix magazine.