Thanks for the measurements. For a passive crossover you can use a contour circuit to equalize the upper octave a bit but at the expense of lower overall response (less sensitivity) for the Pt2 line. If you have tone controls or an equalizer, then you can sweeten the upper octave a bit to your taste.

Before you do anything though, I suggest that you listen and decide if you have adequate treble from the array. All too often you might find that a flat response all the way to 20 kHz will sound a little too bright in-room.

Jim