Amp gets power but sub doesnt work, help me

[Monsoon26]

Took a video of my settings on my HU and Amp.



So do i need a new sub? or is it something i can fix? I dont think its blown since it still produces all the bass just the lower stuff sounds like crap.

 

[CrossoverOre 10+ year member]

meter the sub and see what the ohms are resting at. Also gently depress the sub and see if you feel anything scratchy.