So, I messed up a little...

[Gray]

Thats what a subsonic filter is,does

What Is a Subsonic Filter

A subsonic filter is a component on your subwoofer that reduces the intensity of notes which come through at lower frequencies. It decreases the amplitude of those low notes that you feel more than…

arendalsound.com

I have no involvement with subwoofers Gas (because my house ain't detached).
But yes, I see that article explains that a subsonic filter is a high pass filter 👍

 

[CGMe]

Small update: After having contact with the hifi store I decided to have them fix it. A new driver will be placed after which they will do some measurements to ensure noting else in the speaker has been damaged.

About what caused it; they couldn't really say (yet). When I get the speaker back I will -very carefully- test some different scenarios to see if I can rule some things out.