Sorry to bore long-time readers with this yet again, but here is the history of the AR-2 series:
The original AR-2 was a 2-way that came out around 1957 a 10” cloth-surround woofer with two angled 5” mid-tweeters.
The 2a followed and added the 1 3/8” ‘fried egg’ dome tweeter, making it a 3-way speaker.
Then AR replaced the dual 5” cones with a single 3 ½” cone, creating the 2x (2-way) from the 2 and 2ax (3-way) from the 2a. This was around 1964-65.
In 1970, AR re-did the 2x and 2ax, with very extensive modifications (although no model number change). You’ll have to examine your speakers closely to determine their vintage.
The ‘new’ 2x replaced the 3 ½” cone tweeter with a 2 ½” unit. The crossover went from 2000Hz to 1200Hz. The logo went from the square “AR” to a rectangular brass logo with de-bossed red ‘2x’ lettering.
The woofer went from a cloth surround to a foam surround. It would be highly unusual, to say the least, for a foam surround from 1970 to still be intact. A cloth surround from 1965 may not have crumbled into non-existence, but it is quite possible that it has dried out and become porous, requiring re-application of a suitable surround sealing treatment.
Check your speakers to see what age and variant they are. The 2x has never had a ‘bright’ character and it is not unusual for people to feel that it is somewhat reticent or “rolled off,” as you say. But “rolled off” shouldn’t mean “deficient.” The 2x (and its 8” cousin, the 4x) have a very pleasing, neutral tonal character that is quite satisfying on a day-in, day-out long-term basis.
Thanks for the info. They have the 2 1/2 in. tweeters and definitely a 10 in woofer with foam surround. It looks like someone did the surrounds already since they are in decent shape. So I guess I will pull a woofer and see what caps are in there. The pots are probably filthy so will spray them with contact cleaner. Still, the tweeter is nothing to write home about from what I can tell. I guess the best course of action is the replace the caps, clean the pots (or bypass them) and of course measure the resistance across the disconnected tweeter to make sure it is the same as the good one. Then, if I can get the other tweeter to work I can listen to what they can do. I suppose then that if I want to swap tweeters I need one that fits the opening, is the correct impedance and sensitivity, and can make it down to 1200 Hz, pretty low. Is there any documentation of the specs of the 2 1/2 tweeter?
I have a pair of KLH 17 that I rebuilt and they are pretty nice. Highs there are somewhat "rolled off", but mids to die for. These smaller AR speakers are what they are, not in the same league as their bigger brothers, but quite enjoyable. I have been listening to a pair of Klipsch Cornwalls lately that I turned into CornScalas. They are pretty amazing, but I always like playing with the AR speakers and always pick them up when they are a bargain. Then I find good homes for them with friends.