Edgy, bright highs on Avantgarde Duos

The Duo's sound best if you are sitting further away from them than conventional wisdom dictates(further from them than they from one another), or- If you have the room, just open up the triangle. The horns are spaced apart to the degree that their voices do not combine(no coherence) for a few extra feet. If the high freq. horn is at ear level, and you're too close: That's almost all you're hearing. They also like to be placed closer to the back wall than most systems. Try adjusting them and your listening position accordingly before making any other changes. Further- They will act as a magnifying lense for any and all shortcomings in the system before them. How "hard" is your room? If you don't have carpeting, curtains, soft furnishings, etc. to absorb some of the highs: they can reverberate to an annoying degree also(especially if the room is small).

Thank you for such informative advice. At this point, Art Audio Carissa, ASL Flora and Synergistic Research cabling. Set up seems more exacting with these speakers than with conventional designs.

Yeah, it's a system, not a set of speakers!
go tube gear throughout (as the subs are already using SS amps to drive the woofers).

Chris, why not try your Audio Aero monos on the Avantgarde? Do you happen to know how many hours of break in there are on the Duos?