crossover design for a sealed MTM

Can someone help me with a design for a crossover for my sealed MTM. I am a novice speaker builder who has gone through an entire roll of solder to try and find the right design using standard crossover formula’s (don’t have and measuring equipment and no LEAP software). The units I am using are Vifa’s TCWG49-08 (Qms:2.62, Qes:0.58, Qts:0.47) and Audax TM 025 F1. The net voulme of my box is about 1.7cft.

After several frustrating attempts at 1st, 2nd, 3rd and 4th order filters I am currently running a 4th order at about 2000hz which has given me the cleanest sound so far. I Need desperate help to improve the crossover.