I have played around with plenty of full range drivers and have a few of TB's finest laying around. I even have a pair of FR-125's, full range drivers, as computer speakers on my desk. As good as they are, and even though they do have good extension to 20kHz, there is no comparing them to a decent tweeter from 2kHz and up.

Any time I start thinking that the FR-125 is really good, I compare it to our A/V-1 and realize how much of a compromise it is for a full range driver (at least receiving a full range signal) to have to do everything and do it all at once. Our A/V-1 blows it away.

I get the same impression from those line sources. They had a dull, slow, and rolled off top end.

They can EQ the hell out of them and get back some top end output but that does nothing for the resolution or detail level or the fact that there is still comb filtering all over the top end.