Perhaps the angle has something to do with time alignment. I do not know. But there are two indentical midrange drivers, one above the other. If time alignment was an intended design element embodied in the tilt of the speaker, wouldn't these drivers be time aligned with one another only at listening positions along the axis perpendicular to the face of the cabinet, where they are equidistant from the listener? So in the end there would be only one time-aligned listening height at a defined listening distance? Hmmmm. The cabinet tilt-back does look nice, though, and I think these guys often get way too much credit for their design choices.
As for toe-in, I do indeed toe them in, and after much trial and error I prefer toe-in such that they cross about a foot in front of the listening position. This gives great imaging--it seems to be best at keeping sound collapsing back into the speakers, so to speak. And it does help HF extension. Even so, even with sizzling Krell FPB 750 MCX amps the Andra IIs seem to me to remain somewhat dark until the tweeter is aimed a bit lower than intended.
I intend to do some Room EQ Wizard measurements to see how the tilt affects upper octave measurements relative to the rest of the spectrum.
As for toe-in, I do indeed toe them in, and after much trial and error I prefer toe-in such that they cross about a foot in front of the listening position. This gives great imaging--it seems to be best at keeping sound collapsing back into the speakers, so to speak. And it does help HF extension. Even so, even with sizzling Krell FPB 750 MCX amps the Andra IIs seem to me to remain somewhat dark until the tweeter is aimed a bit lower than intended.
I intend to do some Room EQ Wizard measurements to see how the tilt affects upper octave measurements relative to the rest of the spectrum.