Introduction: 2.1 Channel Cantilever Bluetooth Speaker
This stylish bluetooth speaker was designed to not only sound great, but to be built with everyday woodworking tools and by someone with intermediate to more advanced woodworking skills when following this build plan. The construction follows simple butt joints, but if you are a skilled woodworker and have the right tools, you can easily adapt this build to use mitred corners for the main enclosure. Finishing is up to you. The build video will show you how to veneer the enclosure, but you can just as easily give it a high gloss paint finish if you wish.
I used 12mm (1/2 inch) Birch plywood to construct the main enclosure and the devisions inside the enclosure and 12mm (1/2 inch) MDF board to construct the speaker stand, but there is no reason why you can’t use Birch plywood or MDF board for all the parts depending on your finish.
This is an overview of the build, with build plans available for download.
Step 1: What You Will Need
The build uses a 2.1 Channel TPA3116 Amplifier Module with Bluetooth 4.0 that produces 50 Watts into two channels and 100 Watts into one channel. It has onboard crossover adjustment of 180 - 250 Hz. The subwoofer is a 5.25 inch unit from Tang Band and the full range drivers are 3 inch units from Visaton.
Electronics, Speaker Drivers & Related Parts:
- Amplifier Module with Bluetooth 4.0 - http://goo.gl/wiBr7d
- Grill Fasteners - http://goo.gl/x8WcFN , http://amzn.to/2cgV5tA
- Switch Mode Power Supply - https://goo.gl/5YGq5u , http://amzn.to/2f5kCCu
- 3.5mm Stereo Audio Jack Socket
- Speaker wire (14 AWG)
- Power cable
- Full range drivers - http://amzn.to/2f5mJWS
- Subwoofer - https://goo.gl/qTDa4tb
- Weather Stripping
- Black speaker grill cloth - http://amzn.to/2g0K7a1 , https://goo.gl/o69VYT
- Polyfill - http://amzn.to/2gnQ8l1
- Power Socket with Switch - https://goo.gl/pz8JmS , http://amzn.to/2glBqtW
- Fuse 250V 5A (EU/UK) or 110V 10A (US)
- Heatshrink Tubing
- Felt Pads - http://amzn.to/2f5mStq
- Veneer of your choice or paint of choice for finishing.
- Your choice of finish (I used a clear polyurethane spray lacquer).
- You can also use a wide paint brush or roller to apply your clear coat.
- Primer for wood
- Black spraypaint
- Silver spraypaint
- Wood glue and Brush for glue
- 2 Part Epoxy glue
- Contact Adhesive
Materials, Tools & Hardware:
- 12mm (1/2”) birch plywood and/or MDF sheet depending on your how you intend to finish your speaker.
- M12 x 100mm (1/2 inch x 4 inch) Bolt and Nut
- 6x25mm Black Drywall Screws (x16)
- 6x20mm Black Screws (x8)
- 70mm (2 3/4 inch) Hole Saw - http://amzn.to/2g1HlEa
- 92mm (3 5/8 inch) Hole Saw - http://amzn.to/2gnxf1S
- Hole Saw Mandrel - http://amzn.to/2gnAh5Y
- 25mm (1 inch) Forstner Bit - http://amzn.to/2fm2QMc
- Measuring tape - Square - Compass (to draw circles)
- Sharp pencil
- Table Saw, Track Saw or Circular Saw
- A guide rail and clamps to clamp the guide down if using Circular Saw
- Drill Bits
- Hot glue gun
- Router with flush trim bit and 45 degree chamfer bit
- Brad nailer with 30mm brad nails.
- Finishing or orbital sander with 120 and 240 grit sandpaper
- Wire Strippers
- Soldering Iron and Solder
- Center Punch
- Utility Knife
Step 2: Building the Enclosure
Start by cutting all the pieces that you will need for the build from the 12mm Birch plywood and 12mm MDF board. Download the comprehensive build plan HERE to get the exact dimensions for each piece.
Use the 70mm hole saw to drill holes in the front panel where the full range drivers will fit. Use the router and a 45 degree chamfer bit to round off the inside of each hole. Paint the front panel black and set it aside to dry.
Continue to build the enclosures that will house the full range drivers inside the main enclosure and the two pieces that will form the speaker port.
Use your router or jigsaw to neatly cut the hole for the subwoofer in the bottom panel. Glue the bottom panel to the enclosure and finally glue the support strips inside the enclosure to which you will fix the back panel.
Step 3: Building the Stand
Glue all the small pieces that you have cut from the 12mm MDF together in a square to form the stand support. Sand it smooth with 220 grit sandpaper, give it a coat of primer and paint it silver.
Drill a 12mm hole in the stand foot piece, sand it with 220 grit sandpaper, give it a coat of primer and paint it black.
Once dry, you can glue the two pieces together using two part epoxy glue and stick felt pads to the bottom.
Step 4: Apply a Finish to the Enclosure
Veneering is not a difficult process, but care must still be taken to get the desired result. Download the build plan HERE to for a guide to veneering the enslosure, or watch the video HERE. Alternatively, you can also opt to stain or give the enclosure a paint finish at this stage. After veneering or stain, apply a few coats of polyurethane lacquer and sand lightly with 220 grit sand paper in between coats.
Step 5: The Back Panel
Measure the size of the cut-out required for the power socket and mark it out on the back panel. Use a drill and jigsaw to neatly cut the hole. Mark the positions for where the screws will go for securing the back panel to the main enclosure and drill the holes. You can optionally also countersink the holes for a better finish.
Step 6: The Speaker Grill
Mark out the position for the holes in the speaker grill and drill with a 92mm hole saw. Next, mark out the and drill the four holes for the speaker grill fasteners with a drill bit that matches the size of your speaker grill fasteners.
Before we cover the speaker grill with fabric, give it a coat of black paint so that the wood will not show through the fabric.
Lay the speaker grill fabric out and cut it slightly oversized. Coat the edges of the speaker grill with contact cement (2 coats). Let it dry for 10 minutes. Stretch the fabric over the speaker grill, sticking the fabric to the edges. Trim the excess fabric with scissors.
Insert the grill fastener pegs into the holes of the speaker grill, and the plugs into the holes on the front of the enclosure.
Step 7: Mount the Speakers
Step 8: Connect the Electronics
Use the hot glue gun to fix the power supply and amplifier module in place inside the enclosure. This is also a good time to fill the enclosure with a few small bundles of polyfil.
Step 9: Attach the Stand
You can now use the M12x100mm bolt and nut to attach the stand to the enclosure. Close the back panel and screw it down. Attached the power cord, switch the unit on and test it.
Step 10: Sound Test
This is a very basic sound test to give you some idea of what this speaker sounds like. It is of course best listened to through headphones at a moderate volume level. It was recorded via a Zoom H1 (http://amzn.to/2gcpLwE) microphone at a listening distance of roughly 2 meters.
Step 11: Detailed Build Plans
For detailed build plans, parts and components, wiring diagrams and how to setup the crossover and levels on the amplifier module, check out my comprehensive build plans HERE.