When making a bass/paper test, finding the "sweet spot" is essential in how you place the paper and pads to get the best effect, however, different sweet spots produce different visuals of the bass SPL slam transfer, which effects how the paper reacts.
In the above test, the paper/pads is positioned to create maximum paper resonance - ie you can hear the paper vibrate.
In the below test the paper/pads are positioned to give a paper "wobble/wiggle" effect.
King cannons like the SZ2000 have this ability - check out both videos to see differing paper responses but both equal in impact, just different types on show
When wearing your Headcans - always make sure you find your sweet spot - if you don't get a good seal, you lose bass impact - and that just ain't no good in the hood