Never done a 4th order and since I have a plethora of 12s sitting around I figured 40 bucks worth of wood might be worth the investment. I'm using 2 Pioneer TS-W305C single 4 ohm woofers wired to 2 ohms getting about 300-350 watts apiece. The woofers are on the same baffle and offset a little to fit.
32" x 25.5 x 16 Outside dimensions
The sealed portion is 11" x 24 x 14.5" internal dimensions. That should give me about .8 cubes per woofer after displacements (maybe .7 each). Double baffled with the ported section taking up the rest. Slot ported to the drivers side with a 4" x 14.5" x 20" port to get around 47-48hz tuning from the ported section. Again after reading a ton on 4th orders I'm pretty sure I know less than I did when I started. Any critiques or suggestions are welcome. And if i screwed it all up thats cool too just a sketch at this point.
Next might be a 4 12 6th order if I like the 4ths output.