My daily driver is a 1992 Honda Civic, one of the easiest cars to break into (and steal) there is. I have always sought to keep it looking as meek as possible, giving no one a reason to want to break into or steal it.
Years ago I turned the factory radio into a secret compartment, and put a touchscreen head unit below in the console area(w/ bluetooth and all that jazz). I also had a 12" sub in the trunk, but that was loud enough to bring bad attention itself, so I found a different option.
I had a home theatre 8" amplified Boston subwoofer the was in a ported box. The amplifier had crapped out, so this was a perfect candidate to repurpose.
I also had an old bucket with a crack in the bottom that I was contemplating throwing out.
Step 1: Design
Measuring the inner dimensions of the Boston enclosure I was able to find out the inner volume was roughly .4 cubic feet. This is important and makes this build much easier. Boston spent time making sure this woofer would work in that size enclosure with that size port, which means if the inner volume of our new enclosure is within 5% or so of that, it will sound killer.
The bucket was 10.25" in diameter at the bottom, which meant there wasn't room for the woofer and port togethor on the top or bottom surface. I decided to go woofer facing down and port facing up.
For the rounded walls of the box I decided to use my circular saw to kerf 1/2" MDF at 1.25" intervals, allowing me to bend the wood into a cylinder.
My cut list consisted of:
-Three 10.25" rounds, one with 7.5" hole in the middle
-One 10.75×32"ish piece, kerfed ever 1.25".
The pics show my spectacular drawing and handwriting skills as well as some mathematical shmathsmaticals I used to get my demensions.
Step 2: Cut and Kerf
I put a screw in the 5.125" hole and cut three 10.25" rounds out of 1/2" MDF (I drop the bit in 1/4" and do 2 passes to complete each round).
I used double sided template tape to tape one of the rounds down and utilising the same center hole on the round, put a screw through the 3.5" hole on the circle jig and cut that round out same way, forming the mounting hole for the woofer.
Used the circular saw to cut a 36"×10.75" board, then clamped it down.
Set the circular saw blade depth to around 3/8" and kerfed the whole piece at roughly 1.25" intervals.
I had some 6" chunks of fiberglass tentpole(leftovers from a repair kit). I used the coping saw to cut four 1" chunks to act as spacers.
Step 3: Assembly
I grabbed the saw dust bag from my miter saw, wood glue and a spreader.
I poured some dust and wood glue out and mixed using the spreader til it was thick enough to not run, then I spread and filled all the kerfs as best I could. It was messy but MDF is just glue and saw dust, so this is a perfect filler.
I then rolled it into form, put glue on the top edge and used my brad nailer to mount the top round in place, flipped it, and attached the other. I used my finger to "clean up" all the glue that was pushed out of the kerfs.
I used a 3" hole saw to drill the port hole. Hot glue held the port and flared ends togethor in the old enclosure, so I used the same to mount in the new enclosure.
I drilled a 3/16" hole for some speaker wire and used hot glue to seal the hole.
I used but connectors crimp connected the speaker wire to the terminal wires on the woofer.
I then predrilled the woofer mounting screws and mounted the woofer down.
I then laid my last 10.25" round on top of the woofer and used a countersink bit to predrill holes for the 1" spacers.
Put the spacers and screws in and tightened it down. This left an inch of space for the woofer to play and a 1/2" MDF base for it to stand on.
Step 4: The Bucket
I flipped the woofer enclosure upside down and put it on some blocks, then put the bucket over.
Predrilled 4 holes and used some stainless screws to hold it in place.
Step 5: Make It Discreet
I then used a staple gun to create the illusion the bucket was stuffed with this black felt.
I decided it needed some added touches so I grabbed some trash from around the shop, used disposable gloves, foam brush, masking tape, and wood glue covered paper towels and stapled them in strategic heavily thought out location.
Step 6: Testing
I ran new speaker wire from the amplifier(located in the trunk) to under the backseat where I could easily connect and disconnect the bass bucket if I needed room for something, like people.
It sounds great and does exactly what I need it too. The last photo is what a potential thief would see if they looked in, pretty unassuming I think.