Tang Band W5-1138SMF passive radiator micro subwoofer

A few years ago I made a small, poorly made box for a Tang Band W5-1138SMF 5 1/4" subwoofer plus two 6 1/2" radiators. It worked and sounded alright but now that I have developed better CAD skills and understand the modifications I wanted to make to the speaker enclosuer I decided to build a better box. The volume is 16L (0.56 cubic ft). Volume and tuning of the radiators are derived using the T/S parameters for a ~QB3 alignment. The total print time was 1 day and 5 hours, and I didn't face any assembly issues. I sealed the driver and radiators with foam tape. Speaker cable exits via a 10mm hole at the bottom, filled with hot glue. Hooked up to a TPA3116 amplifier board with signal taken from the high level output of my stereo amp. Here are the CAD files on Onshape for the speaker box and amplifier enclosure. 

List of parts:

Tang Band W5-1138SMF 5.25 inch subwoofer

Dayton Audio DS175 6.5 inch passive radiator (x2)

Dayton Audio DRFS1 rubber feet

Gasket Foam

M4 heat set inserts

M4x16mm screws

~48g of fender washers (~4 each) per passive radiator

The print came out without any issues, but could be tricky given the large size and supports needed. I chose to print with one of the passive radiator sides facing down.

Print settings:

Elegoo Rapid PETG (~2-3x spools)

0.6mm nozzle

0.42mm layers

3 top and bottom layers

2 walls with alternating extra wall (Orcaslicer v2.3.0)

10% cross hatch infill

Scarf joints

Tree supports (15% branch density, 60 degree support branch angle, 40 degree preferred branch angle)