I just got this bad boy brand new from HSU and installed it in the corner. One port open, eq set to "1". Gain is set at 12 oclock, internal crossover disabled, crossover in the Denon amp at 80Hz.
Getting a strange rattle from the subwoofer cone on certain very low passages where the bass is a longer extended note.
It is not from the enclosure or the surrounding wall/baseboards etc.
Noticed this on very deep musical bass heavy tracks like Impend from Halo 2:
And also Heretic, Hero from the same soundtrack.
.
Everything appears to be in order on the sub, all the face mounted screws are tight.
Suggestions?