Hey all, I drew up a design for a vented enclosure for a 12" Polk subwoofer in my car, and before building it I wanted to run it through people with experience to see if anything immediately stands out as a problem. This is my first build so bear with me

So the outside dimensions are 28" x 15" x 14", using .75" MDF. The net volume is 1.54 cu. ft., and the port is slotted at 12.5" x 2", tuned to 27.4Hz at 54.75" long. The sub is a Polk Audio MM1240DVC, and the suggested ported box volume is 1.58 cu. ft.. I put in the values to Speaker Box Lite for android and came up with a few graphs.

Ignore the green line, the red is the ported box I designed and the blue is a 0.8 cu. ft. sealed enclosure, which is what I used to have the sub in.

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Imgur: The most awesome images on the Internet

I'm not really familiar with phase response, does this all look good? My goal was to get a smoother (less punchy), deeper sound from my sub. The sealed enclosure I have sounds tight and clean, but I wasn't satisfied with how early it rolled off. I wanted to try and create a vented enclosure that was much deeper but still relatively responsive, and clean sound is also important.

Also here's a rough sketch of the design itself. On the final design i planned on putting angles in the corners of the vent to allow the air to travel more smoothly.

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