How to Make a Bluetooth Speaker with Box Joints
Build a gift and learn a new woodworking technique in the process.
A full day
IntroductionSure, a store-bought speaker can sound good, but how attractive is a plastic box? Here's a hand-built heirloom speaker that really turns up the volume on looks. Making a speaker yourself allows you to mix and match hardwoods. This one, made of elm and maple, is constructed with box joints, making it as fun to build as it is to give.
- Dado blade
- Hole saw
- Miter gauges
- Orbital sander
- Table saw
- Trim router
- 1/2” square dowel
- 1/2x6x2’ maple
- 1/2x6x3’ elm
- 3/4” plywood scrap
- Fawn Bluetooth Speaker kit
- No. 6 screws (3/8” long)
- Small coil of solder
Buy a kit
You’ll find several speaker kits available online. For this project, we used a Fawn Bluetooth kit from KMA kits, which features easy connections. Most of the connections are made with plugs; only the component terminals require soldering. A beginner with a $5 soldering iron can get the job done.
With our easy-to-build jig, a pair of miter gauges and a table saw, you’ll be able to add box joints to your woodworking repertoire. Getting the jig adjusted will take a few tries and a bit of patience, but once it’s dialed in, you’ll be set up to cut box joints forever. The best part is that you can reuse the jig for other projects.
To cut box joints, start by building a jig for your table saw. First, cut all your parts to size, including trimming the 1/2-in. square key stock, and then change your table saw blade to a 1/2-in. dado stack (Photo 1). With the miter gauges in the miter slots, fasten the fence through the back of the miter gauges with 1-1/4-in. screws to make a sled. Clamp the plate flat against the fence and push this setup through the dado blade. Unclamp the plate and glue a 3-in. length of 1/2-in. square stock into the cut you just made. Create a space between the key and the blade using the remainder of the 1/2-in. stock; this makes the pins and sockets the same size (Photo 2). Clamp the plate to the fence.
Project step-by-step (11)
Set up the dado blade
Set the dado blade height a hair taller than the thickness of your material. The dado width should be 1/2 in. to match the width of the key stock.
Position the key
Use the leftover 1/2-in. x 1/2-in. stock to position the key away from the blade. The widths of the blade, the spacer and the key must be equal. Clamp the plate to the fence.
Cut the first pin
With the jig adjusted, make a test joint to check the fit. Your goal is to get the fit nice and snug. If the joint is loose, the pins are too small (slide the key away from the blade). If they don’t fit, they’re too big (slide the key toward the blade). For the first cut, push the edge of a top/bottom part (A) flat to the table and against the key and make a pass.
Cut more pins
Make a reference mark on the front and back of this pin to help set up the cuts for the sides. For the rest of the cuts, fit the socket over the key, hold it in place and make each pass slowly.
Cut the side pins
To cut the sides (B), flip the first board so the reference pin is between the blade and the key. Push the edges together and make a cut. Make the rest of the cuts, and then flip the boards end over end to make mirrored edges on every board.
Glue cleats to attach the panels
Scribe a line 5/8 in. in from the edges of the panels and glue the eight cleats along the inside of these lines. Attach two cleats (C) to the inside of each part to fasten the front and rear panels.
Glue and clamp
Scribe a line 5/8 in. in from the edges of the panels and glue the eight cleats along the inside of these lines. These are glued 5/8 in. in from both the front and the back of the enclosure. Be sure the joints fit together correctly, then apply glue to all surfaces of the sockets and clamp them tight. Check the diagonal measurements of the box from corner to corner to ensure that it’s square.
Bore holes for the components
Lay out the components on the front (D) and back (E) panels, mark their centers and drill the appropriate-sized holes following the kit instructions. Some of the components require material from the back of the panels to be removed in order to fit. Use a Forstner bit to remove enough material from the back (without going through) to allow the components to be fastened with a nut on the front side of the panel. For larger holes, you’ll need to use a hole saw at the drill press. Drill partway through one side, then finish the hole from the other side to avoid major chipping.
Chamfer the speaker holes
Set up a router with a 45-degree chamfer bit. Start with a shallow cut, then adjust the depth, cutting deeper and deeper until you’re happy with how it looks. Make sure the screws that fasten the speaker to the panel won’t poke through the area that’s been chamfered. When all your cuts are made, sand and finish the assembled enclosure and panels, then fasten the components.
Connect the speaker components
Install the components on the front and back panels and solder the wires to the terminals according to the instructions in your kit. Use hot glue to fasten the amp board to the inside of the box, then plug all the components into the board.
Install the front and back panels
Feed all the wires into the box and screw the rear panel to the cleats, being sure to use pilot holes. Apply glue to the cleats and set the front panel into the box while feeding the rest of the wires through.