In a crazy moment ,I sold my AR 11 speakers here in NZ! Some time later ,I was offered a pair of AR 12 s minus the bass drivers.Always a fan of the bass performance of the 11s ,I was able to mod a pair of 12” bass units into the AR12 cabinets.
I have no way of measuring the bass performance ( except by ear !) but they sound great.
just sold my AR5s sadly as downsizing !