Use a multi-meter to measure the resistance across the speaker terminals. Normally, the resistance should measure around 3 to 6 ohms. If both measure exactly the same in this range, it's probably not the crossover and instead a driver issue.
Driver Testing - reduced output
I have Proac 3.8’s. The right speaker has limited output compared to the left speaker. I tested the cables, amps and other electronics as well as swapping out. I get the same results. I tested the tweeter, mid and woofer drivers with a battery and all but the mid “pop” / produce noise. When I tested the mid with the battery, the woofer driver produced the “pop” but not the mid. Testing the woofer only made the woofer “pop”. Question: is the mid Driver bad or is the crossover doing something that is nulling the mid drivers response to the battery test? The wire is soldered to the drivers, i did not remove the solder before testing. Thanks in advance!