HA Clarus C8SW-D2. 170 watts.

EBP of 113.57 seems best suited to vented.

HA recommended .75 ft^3 @ 38 Hz looks like your best bet for flat response. 35.8 Hz F3. 108 dB @ 44 Hz. Higher Fb and/or greater Vb for commensurately higher (and peakier) output.

One of these https://www.parts-express.com/precis...e-kit--268-350 at 16.4” (32.2 m/s); or a 4” non-flared tube at 28.2” (18.1 m/s). Either should be completely noise-free. Not sure if 32.2 m/s would produce audible chuffing in non-flared tube (3” x 15.3”).