This is interesting because of a few things. A 20dB difference may not be that much if it was say in the range of 50>70 or 60>80. A lot depends on the amp, as some may clip much sooner than others, even in the mid to upper 80's which could cause some damage. Also, the AR's may be old enough to have previously unnoticed surround damage, but that too depends on their vintage & if any repair work had been done. Same thing applies to the crossovers (age wise). Those original pots were pretty crappy & could also be a problem, as they developed "dead spots" because they usually stayed in the same position for years.
OK, things to check. With everything turned off & no ambient noise, gently press the woofer cones in to see if you can hear any scraping noise. Play something you are familiar with & use a piece of cardboard big enough to cover up the other drivers while you listen to one at a time. Does it sound like it should? Not a scientific test but it should give you enough info to get started on making some decisions. Change the spkrs. from left to right (unless you have a mono switch) to see if you can tell any differences.
You could also play the speakers on a different system to test them.
OK, things to check. With everything turned off & no ambient noise, gently press the woofer cones in to see if you can hear any scraping noise. Play something you are familiar with & use a piece of cardboard big enough to cover up the other drivers while you listen to one at a time. Does it sound like it should? Not a scientific test but it should give you enough info to get started on making some decisions. Change the spkrs. from left to right (unless you have a mono switch) to see if you can tell any differences.
You could also play the speakers on a different system to test them.