[AK]

Have you tried to remove side panels? they must be causing strong sound diffraction.
8in to 2000hz? in my little experience, if you like to listen loud, none of larger paper woofers will play up to 2khz.
paper cones are starting to "scream" right after first impedance bump for 6-8in woofers usually around 800hz

[kyrill]

Hi AK

The sn-8mb is designed to be a PA speaker, so made for high loudness

their sensitivity is 95db for one watt and they can have 150 watt

I play averagely between 80-90 db so 1 watt is around the max ( not sudden  but short peak levels)
i listen to. I suppose these drivers even when your story holds for these drivers,  with 1 watt as opposed to the max  they are designed for, i expect them not to break or scream
this is their ( series 1) graph incl impedance