I won't go into a long explanation here because there is already one in the underbar on the video.
But the TL;DR is that I had to pull out my 19 year old, no name shop subs in order to test a t-line I'm building for a customer who will most likely be buying new subs from me now, lol.
And the score so far is:
JL Audo 8w3: Blown surround on 160 watts
Ragged old shop subs: laughed at the little amp an went on to take A Ground Zero 1.800