In reply to:

booms, bangs, roars ... or the cannons from the 1812 Symphony

Keep in mind that the aspect of audio that requires the most power -- bass -- is frequently offloaded to powered subwoofers.

I agree that many A/V receivers wouldn't be able to properly drive a pair speakers to cleanly reproduce the cannon fire found in the 1812 overture without the ability to offload much of the duty to the outboard amp in the subwoofer.