UHFS subwoofer bottoming out?

[KaiserSoze]

Has anyone noticed this? I can hear it on the last bit of "Royals" by Lorde. It manifests as a rattle. Besides the warped sound, I fear it may damage the subwoofer long term. However, I know little of such things.

 

[ernies]

I thought I heard it once, but do not remember what I was listening to. I HOPED it was my imagination. Maybe when I get it back after 17 days worth of work I can test it again.

 

[systemcrashed]

New speakers need to be "broken-in" before being able to respond to all frequencies accurately, this is done by playing a "pink noise" track repeatedly at around 50-75% volume preferably when you are not in the car