Here is yet another variation on the MBOW1 2nd order theme, this time using the popular Seas 27TFFC tweeter. The cost is comparable to the Morel MBT20. The Seas version has a smoother response above 10 kHz, but the Morel version has a more precisely targeted 2nd order high pass roll off, thanks to the MBT20's more benign impedance peak profile. So it's a toss-up. Buy whichever one is on sale. Please note that the tweeter connections are reversed polarity. And don't forget the 50 ohm bypass resistor in the woofer circuit. Finally, feel free to experiment with the tweeter L-Pad values. If it sounds too bright, increase the series resistor by 1.0 - 1.5 Ohms. Oh -- and don't forget that the little resistors in line with the woofer inductors don't really exist. That's just the inherent dcr of the inductors themselves. If you don't want to spend the money or take up the space with 14 Ga inductors, go with 16 Ga. It's no big deal.
The following measurements were made in a cabinet with no edge roundover. Most of the dips and peaks in the on-axis plot above 3 kHz are due to diffraction effects. For an illustration of the difference roundover can make, see A Tale of Two Cabinets.