Niles sw300 sub powered but no output

[Zach_66]

Basically the sub has power but no audio output. It only make garbled muddy sounds even when no audio is passed through. Any ideas what it could be?

 

[Calvin7]

It possibly is connected wrong. Carefully read the manual and recheck all connections.
https://www.manualslib.com/manual/463754/Niles-Sw300.html?page=6#manual

 

[americanaudiophile]

First guess would be bad sub amplifier.