PT Mini 6- Experiences? Splashy treble?

You crossed it right at its resonant frequency where it has a ton of stored energy and rings like a bell. Your ND65 is good out to 10k……try again around there instead…….the off axis dispersion matches up pretty nicely there as well.

BUT if you do this, you can’t stack the drivers….it will lobe like crazy. Mount the PT besides the 65 as a little cube. Get it up off your desktop around 12” to avoid early reflections which are super destructive in the nearfield