A bigger box will struggle to fit in my car, the 12inch sub stopped working and i have a spare 15 inch sub with no enclosure.

I decided id try to fit the 15 in the 12's home.

Step 1: Hold a Ruler on It and Scratch Your Chin.

Tools used, large soldering iron, drill, jigsaw, rasp screwdriver, wire cutters/ strippers. metal rule. staple gun. chinagraph pencil.craft knife.

Materials involved, 12in sub enclosure, 15inch sub 250/1000w ,2ch mosfet amp 150w ,1farad power cap. zip tie ,staple . rca leads, 40a fuse and holder. power cables

note some of the materials were already installed in the car.

Step 2: Then Make a Plan

Decided that an free air design was acceptable.

I flipped the box.as the base is a tiny bit wider than the top.

Step 3: Mark Where Goy Gonna Cut.

Draw around the speaker with a chinagraph pencil, then draw a smaller circle insideby hand, to allow for the mounting edge of the speaker.

Take the carpet off where cutting so it does not snag the blade or loosen the carpet, leave some where the mounting edge will sit.

Step 4: Pilot Hole and Jigsaw.

where i got close to the edge i held the saw at an angle.

Step 5: Fine Tuning the Hole.

there were some lumps to rasp off, i took a little bit off then offered up the speaker to see how it fitted. repeat untill the shape is correct.

Step 6: Screw the Speaker in Place,and Add Some Wires

a 100w iron makes light work of soldering heavy cable.

Step 7: Power Wireing

Having the access in the bottom of the box, i decided to hide the power cap inside, this makes it less likely to give me a shock when rummaging around the boot (trunk)

I soldered the wired before putting them in the choc terminal block. i use a chock block because i occasionally need to take the sub out if i need to move a large load of stuff.

note that i have not put the rca audio leads on the diagram.