I'm sure you've done this but I'll suggest it just in case - it never hurts to double check connections - Check the wiring and make sure the bass bin, midhorn and tweeter are all connected to the right outputs on the crossover PCB and also make sure they're all phased properly.

If you connect the midhorn to the bass bin output and the bass bin to the midhorn output, it will sound pretty unnatural, but you might not catch it right away like if you reversed woofer and tweeter connections. You'll still have bass and midrange if cross-connected, but the bass is weak and the midrange is hollow sounding and rolled off early. So check that and make sure it's right.

Also, check the polarity of every connection. The midhorn and tweeter in particular, if phased right sounds like a single driver, if not, sounds like the tweeter and midhorn are independent of each other, you can really hear the disconnect. So check everything and make sure it is all connected properly.