How to Build a Sealed Box Speaker

A sealed speaker box refers to a type that is designed to be airtight. This makes the overall sound of the box deeper, making a sealed box speaker ideal for bass response. These boxes are the easiest kind to build, and some experience with carpentry or woodworking and a little soldering will put one together in a short amount of time.

Things You'll Need

• Tape measure
• 1/2-inch plywood sheets
• Marking pencil
• Table saw or circular saw
• Speaker
• Drafting compass
• Wood epoxy
• Screwdriver bit
• 1-inch wood screws
• Jigsaw
• Electric drill
• Drill bit for speaker-mounting bolts
• Medium-grit sandpaper
• Speaker wire
• Wire cutters
• Wire strippers
• Soldering gun
• Resin-core solder
• 1-inch bolts with T-nuts for mounting speakers
• 1/4-inch drill bit
• Speaker plug jack
• Pliers
• Fine-grit sandpaper

Instructions

1. Draw the dimensions of all sections of the enclosure (top, bottom, two sides, back and front speaker-mounting board) onto the plywood using the tape measure and pencil. The size of the box will depend on the size of the speaker you are placing in your enclosure. Cut out these sections with a table saw or circular saw.

2. Place the speaker in the middle of the front mounting board (known as a baffle) and draw a circle around its circumference. Put a mark in each hole of the speaker flange for the mounting-bolt holes. Remove the speaker.

3. Draw another circle inside the circumference circle with the compass (this should be at a distance equal to the distance between the bolt holes and the circumference circle).

4. Attach the two side sections to the bottom section with epoxy. Epoxy the top section to this structure to make the basic sealed speaker box frame. Epoxy the baffle to the front of the enclosure.

5. Install wood screws into all joints where the sections meet with the drill and screwdriver bit, starting at the corners and installing screws 2 to 3 inches apart.

6. Cut out the speaker hole using the jigsaw along the inner circle on the baffle. Bore out the bolt holes with the drill and a bit that is smaller in size than the diameter of the mounting bolts. Sand down all cut edges with medium-grit sandpaper.

7. Cut off a piece of speaker wire with the wire cutters long enough to reach from the baffle to the back of the sealed speaker box. Strip one inch of insulation from each end of the cut piece of wire with wire strippers.

8. Cut apart the leads at each end of the wire with wire cutters to a distance of one inch. Connect the leads of one end of the wire to the speaker terminals with the soldering gun and resin-core solder.

9. Mount the speaker on the baffle with the bolts and T-nuts using the drill and screwdriver bit. Change to the 1/4-inch bit and drill a hole in the middle of the back section of the enclosure.

10. Install the speaker jack plug into the 1/4-inch hole and tighten down with pliers. Solder the leads of the other end of the speaker wire to the jack plug terminals.

11. Epoxy the back section to the box. Secure with wood screws and the drill with the screwdriver bit. Allow the epoxy to dry.

12. Smooth down the exterior of the sealed speaker box with fine-grit sandpaper to prepare for the desired finish (paint, stain or fabric).

References

• DIY Guitarist: Building a Speaker Cabinet
• Instructables: How to Solder
• TermPro: Mounting the Drivers