Can you elaborate on your design goals as to what target system your after and sound ideas your after. What size Speaker are you designing?
I look for a speaker that engages me that is musical and invites you into the music apposed to overly analytical. I do like it to be detailed but not in your face. I'd also like it to have high efficiency and an easy load on the amp. Also something that is not designed to impress you in the show room but over the long term is unsatisfying. most times this is when they boost bass or other areas. I like a realistic sound that is true to the source. Having options as to placement would be nice. I also like a speaker that disperses into the room more I'm not a fan of the pin point sweet spot as I like to move around when listening.