I've been working on a fun project... making an open baffle bass speaker to play into my stereo hi-fi setup. My main system is a tube amp powered set of Omega Custom Shop RS5 and although they sound amazing, they only play to around 55Hz on the low end. I was considering a subwoofer project, but then a vintage paper cone woofer came into my view for $20 and I thought that it might be more in tune with the character of the Omegas. I know it won't reach modern subwoofer levels, but I mainly listen to jazz and ambient music and feel like it'll do just fine.
Materials:
4’x8’ sheet of 1/2in plywood
Wood glue
Finish - I used shellac
Piano hinges - 30” length
Tools:
Circular saw or table saw
Jig saw
Router
Phillips screw driver
Loudspeakers by G.A. Briggs
Download the cut list
Start by breaking down the full sheet as specified on the cut list, and preparing for gluing the layers. Once cut, I glued and clamped all pairs together and left to dry overnight. The larger panels were weighted in the middle first with sandbags and tool bags to eliminate any interior pockets. There’s lots of better ways for glue-up, like vacuum bags and whatnot, but we’re going as simple as possible. Just make sure to press as much as possible to remove gaps before the sheets dry.
Once all parts are glued, I sanded the edges smooth with 40/60/80/100/120 disks until they were smooth to the touch. Be careful with the veneered faces, I only used 120 at a slower speed because it’s easy to sand through. I did round all edges and corners moderately, but this is up to your preference. Good idea to break the edge at minimum so the ply edges don’t get snagged when moving around later.
Measure your speaker and decide where on the panel you’d like it to sit. I placed mine off-center and closer to the floor to help spread out the frequencies where front-to-back cancellation occurs, while using the floor as an additional acoustic boundary.
Cut your speaker hole with a jig saw, or circle cutting attachment on your router. Then round or bevel the outward edge with a router and sand smooth.
Apply your favorite finish to all panels, I used shellac for its fast drying and simplicity. Follow your finish instructions, I sanded lightly between 2nd and 3rd coats. Allow to fully dry or cure.
Attach wing panels with hinges, be careful to install piano hinges straight to prevent binding on fold-up. One of mine groans because it’s a little bowed… oops.
Once fully assembled, lay face down and install your speaker cone. I attached with 1” saber-drive screws with washers at a low torque setting. Be careful to not strip out in the ply and/or overdrive and warp your speaker basket.
Now attach wires and test! I ran mine in full-range mode at low volume for a few days before applying the network. Didn’t sound nearly as good because it messed with my stereo separation, but then when you apply the crossover network, you’ll be blown away!
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