Play them at low volumes and put your ear up to each driver to make sure each of them is working. I know of at least one case on here who had a pair of M22's that would shut down a receiver at a certain point which was caused by a defective woofer. After the woofer was replaced, no more protect mode.

I’m armed and I’m drinking. You don’t want to listen to advice from me, amigo.

-Max Payne