Mystery Sub Level Controller

[OldJimi]

There is a box mounted on a wall behind the TV in the living area that I haven't been able to figure out - small few inch by few inch mounted side ways with a rotating knob with labels for Min and Max, PWR with a light I've never seen lit, and marked " Sub Level " at the top.

I'm thinking it could be for the JBL subwoofer mounted nearby, but audio instructons don't mention it.

If anyone knows, please share, thanks.

https://www.montanaowners.com/forums...pictureid=3036

[Lee-CI]

Suspect this is for stereo subwoofer

[Foldbak]

Yes it's for the sub woofer.