My nephew is a good kid (if you can still call a nearly 30-year-old man a kid anymore). When we go on vacation, he will often housesit, feed the dog and cats. Growing up, he was always willing to help my wife with whatever tasks she needed. A few years ago, he wanted a big subwoofer to fill the back of his Chevy Suburban. How could I say no. We talked the better part of a year or more about wood options and settled on Baltic Birch plywood. He bought the plywood in Winter/early Spring of 2022 at $250 a sheet and we needed 2 sheets. I felt bad as the prior year, the same 4x8 sheet of Baltic Birch plywood cost $90. Nothing either of us could do at that point.
Since he's an audiophile, I let him look into the design for a subwoofer box. The dimensions needed to have proper air displacement and funnel air. Interestingly enough, the design he provided me (including dimensions) matched the design I had seen in a used 1970s RadioShack (remember them?) book on building speaker boxes. That made me feel confident about the build. In terms of the build, the plan was to use dovetails and I would make them on the order of a fat 1/16" to skinny 1/8" proud to add some shadow dimension to it. The finish would be garnet shellac. I had a few pine pieces I had made with garnet shellac and he liked the way it looked on wood.
I thought it would likely take me about 100 hours. I was fine with that. The challenge, in the fun sense, was going to be the size of the project. It is 4 feet long x 18" high x 2 feet wide. That's a big box. Cutting and clearing the dovetail waste wood would be straightforward, though it plywood with glues that are hard and dull chisels a bit more quickly. It was doing the transfer that I was really worried about.
The other challenge was actually getting to do the project. Like many, I am slow, and I didn't want for him to wait a long time. Even though he wasn't paying, I still wanted to get it done sooner rather than later. I started in the fall of 2022 but had to stop to working on it to get to Christmas gifts and then the Shaker table inlay idea added a bunch more time to that project. As such, I didn't get back to this until April. I really hated having a 5-month hiatus. Again, he's a good nephew and didn't complain.
As for the dovetails, I used a symmetrical design from the centerline. Bigger in the middle and then progressively each tail on each side was symmetrically smaller. I liked the way it looked on a storyboard. For added measure, I added a houndstooth dovetail in the middle tail. I had to do six corners rather than the standard 4 because of the air intake for the subwoofer.
This is the first project where I really wished I had a table saw. I hadn't started the woodworking school class so that wasn't an option. I tried at first to cut with a handsaw but that was going too slow. As such, I pulled out a corded jigsaw and used it. That worked quickly. Honestly, coming from a perspective of ripping and cross cutting by hand, using a jig saw made me feel very happy at how much speed it provided. I had a really tough time trying to get all corners square. Again, a different size for me and even with my 24" beamed engineering square I felt like I was constantly chasing my tail. I got it close enough.
Cutting out the tails first (as is my habit) was straightforward. Removing the was a combination of using a coping saw then using a right-angle piece of wood and pairing to the base line. I initially tried a fret saw but the blades kept breaking so a coping saw was the way to go. Things were big so it took time and I needed to sharpen more frequently but it wasn't that bad.
Transferring the tails was a bit difficult for some boards due to the size. I just moved the bench away from the wall to give me more options for clamping. Given how many tails there were per side, getting the proper fit of a pin and tail assembly took a while but I got there.
Then, it was time to do some reinforcement on the inside. Part of that was in the building diagram. I also added some L corner reinforcements. I don't know what the forces of a large subwoofer will do. I figured gluing and screwing on the inside was a good safeguard to keep things from shaking loose.
I did learn one lesson the hard way. Yes, I label my pieces. HOWEVER in this build, I was a bit sloppy in that some of the writing meant different things. When it came time to glue and screw the interior supports I did NOT read the writing and just visually used it to indicate which side to glue the bracing to. Turns out I glued two of the six board's interior bracings to the OUTSIDE face. Arrugh! I was really upset with myself. One big piece where it would definitely show I just remade the piece. The other visible face on the visible side of the air intake really wouldn't be seen. There, I was able to remove the cross bracing and use a hand plane and card scraper to clean things up. LESSON LEARNED: be 100% consistent in HOW you label. If I had read things carefully, I would have avoided the issue. I didn't read carefully and that is my fault. By using consistent surfaces for writing in a consistent manner, there is just one less chance for error.
Before glue up, I put the garnet shellac on the exterior faces. Glue was done with one side at a time in the clams overnight. During the dry practice, I knew all would seat well and the dovetails did seat very well. The top and bottom were just attached with screws. Again, I don't know how the piece will hold up and I want to give my nephew options for repairs if needed.
My nephew will cut the holes for the subwoofers and do the electronics. He's ordering materials that will them look very nice as well. Given it took me about 110 hours to build this, I am fairly certain he will have a very unique subwoofer. He's very happy with the way it came out and I'm very happy to see his eyes light up with joy.
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