Older versions are oriented vertically (up and down) while the newer versions are horizontal (sideways) ... The older ones have a different round tweeter grill and a slightly different tweeter. Newer ones have a different, slightly less harsh sounding tweeter.

I think there was a debate as to what type of tissue to place over the old style tweeters to attenuate the hf at one point.......

johnwy wrote: I think there was a debate as to what type of tissue to place over the old style tweeters to attenuate the hf at one point.......

I remember that...seems the general consensus was to avoid Pufs, as the lotion they put in those tissues wreaked havoc with anything over 6K...and made any reverbs sound a bi too wet...