I've been around long enough to have heard bad speakers poorly set up, good speakers poorly set up, good speakers well set up and well matched to the room with less than ideal ancillaries, but the only speakers I've ever heard where everything has come together are in my own room. At this point, I'd be hard pressed to know how to audition speakers. It is so rare to hear speakers optimally set up that it is anyone's guess if one is hearing a speaker's weakness or the room's characteristics. The probability of beating what I've got is not that great and trying to get the speakers optimally dialed in in my room is daunting.
All that said, the worst I ever heard were Cornwalls back in the mid 80's. Just dreadful. Utterly boring and one note bass that sounded like someone was kicking the belly of a dead cow. The closest to well set up was a pair of Sonus Farber Cremonese. The speakers were well placed in a well treated room and showed some measure of their potential. Ancillaries were not up to the task.
All that said, the worst I ever heard were Cornwalls back in the mid 80's. Just dreadful. Utterly boring and one note bass that sounded like someone was kicking the belly of a dead cow. The closest to well set up was a pair of Sonus Farber Cremonese. The speakers were well placed in a well treated room and showed some measure of their potential. Ancillaries were not up to the task.