First I swapped the speakers between the L/H and R/H channels to rule out the receiver and the problem stayed with the speaker. Then I swapped both the tweeter and midrange drivers (couldn’t be sure where exactly the sound was coming from) between the speakers and the problem stayed with the cabinet and didn’t follow the drivers. I checked for anything loose in/on the cabinet and found nothing so I emailed Axiom with the results of my troubleshooting.
Got a quick reply the it was probably a bad crossover and they would ship me a new one. Since I installed the new crossover there have been no problems.
