andy2 - Up and down is a weak point of minimum phase, multi-driver transducers. The coax is much better than discrete drivers, but coax to woofer geometry still comes into play. Right-left-depth is their strong suit. The up-down problem is exacerbated when the speaker’s aiming is marginal. You want its propagation axis pointing at your ear-plane such that you are at the center-sweet spot of its vertical propagation field.
The design axis assumes an ear position of 3’ off the floor and at least 2.5M - 8+’ away. You can mount a builder’s square, laser, etc. on the speaker at 36" up and parallel to the floor. Sight along that line. Adjust speaker tilt such that it sights to your ear height.
Now it gets trickier. The effective set-back of the drivers changes relative to how much the speakers are toed in, which is dictated primarily by your room’s side walls. If the sight line points at your ear when the speaker is aimed directly at you, it will act lower if pointed more perpendicular to the front wall. (Visualize looking at the side of the speaker rather than the baffle. There will be zero driver setback in that case vs 6° (depending on your model) when looking at the baffle.
Explained another way, if you use setup software, the proper height and tilt is the one that produces the best square wave, step response, etc. at your listening position. That optimized geometry will put your ear at the mid-point of the vertical wave propagation arc. Your soundstage height will be at its best, as well as frequency response and everything else.
