Agreed... lots of midrange in that movie when the tanks fire off. I played the movie for a friend at -5db and he said the movie was perfect and wouldnt' want louder. SPL meter peaks were hitting around 101-102db but most of the movie bounced around the 85-95db range. I never noticed any strain.I am glad you love the movie soundtrack, so do I. But in this case I am not speaking to the "low" in the sound but the impact supplied by the main speakers. This is where the impact of the tank shelling comes from and it will draw an awful lot of power to take command of the woofers and force them to do the right thing. I am sure the guts of a power supple would be severely taxed in these scenes.
This will also put on display many of the short comings of some amps in that they may not have power reserves to keep up.