the 57 is my favorite with a most glorious midrange that I have yet to hear topped, ever, by anything.
a buddy had a pair that we listened to for a few years and when he bought 63s I was always let down a bit by the midrange even though the 63 is more of a full range speaker
a buddy had a pair that we listened to for a few years and when he bought 63s I was always let down a bit by the midrange even though the 63 is more of a full range speaker