Some of the first serious cabinetry I ever built was incredibly utilitarian in nature, but helped pull me into deep end of the live music profession.
As a young sound engineer, there were many days spent far away from the concert stage and huddled in the small garage that served as home base for my first employer, a local sound company based out of rural Maryland. Those days were spent soldering microphone cables, pinning stage boxes, assembling road cases and…building cabinets. Speaker cabinets, that is.
|A speaker cabinet under construction. Proper techniques and joinery are as home here as they are in traditional cabinetry.|
And so it is that I find myself years later finishing a project that I first conceived more than a decade ago to take advantage of some extra speakers and other spare parts I had laying around. With our belated “wedding reception” fast approaching and me responsible for providing a sound system, this was the perfect time to finally augment my little acoustic bar PA with some subs!
|A Pair of "Shy Dog Subs" Not exactly appropriate for an arena, but hugely effective on a smaller scale.|
The single 15” ported sub is loosely based on a Yamaha design, with a few improvements, not the least of which is the material. I eschewed the particle board favored by mass production facrories for 7-ply maple plywood that would be more at home in a world-class touring speaker. All case joinery is done with dados, grooves and rabbets. This not only adds a tremendous amount of strength vs. using fasteners alone, it also helps to airseal the box, which is a crucial step for speaker construction. Sound waves are transmitted primarily via air movement. As such, air leakage is to be avoided at all costs. Seating plywood edges in glued grooves help provide the air seal. For places where grooved joinery wasn’t possible, the wood was mated with a silicone adhesive to keep the air seal intact.
|Air sealing the "handles" that are part of the cabinet with a silicone adhesive.|
Mini-subs like these are really meant to function on their own instead of in the large blocks of cabinets you’ll see in larger venues. Keeping in mind that speakers like this are only going to be used in very intimate settings, I added a speaker pole mount to the top allows them to do double duty and replace the tripod stands that typically hold my hi/mid cabinet’s aloft. Not only do the mini-subs augment the low end of my system, they lessen my footprint as well. It’s a win all around!
|A look at grooved and dado'ed construction. It adds strength and air-tightness to this front-loaded scoop design.|
To complete the speaker, drivers are mounted with metal clamps and then covered with commercial speaker grill cloth. The cabinets themselves are primed with an oil-based primer before being sprayed black and topcoated with a semi-gloss polycrylic, so they’ll look as good as they sound.