That movie is probably too demanding for the EP350. Now it sounds those scenes were overdriving the subwoofer causing port noise or even the bottoming out of the driver.

I would try some different movies that you know have some LFE and never caused these sounds before to determine if it is the movie or that if the subwoofer driver is damaged. The sub should not make a loud bang or pop either at anytime.

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

-Max Payne