You'll need to enter Imperial measurements for Vas, so enter 4.34. Frd = Fts, so enter 37. Qts = 0.32 so enter 3.125 for Qd. If you're using a single woofer, enter 1 for "Qty."

No other items are really important for PiAlign's cabinet computation, except volume offset fields which are at the bottom right corner of your screen. Those can be calculated separately pretty easily, and all the rest of the items are informational only, so you can maintain a database of your designs.

PiAlign recommends a 1.4 cubic foot box, tuned to 45Hz for this woofer. To see the response curve of this alignment, use BoxPlot or something like that to model the cabinet and predict response.