jungimhung

My uncle had this sub in his home theater setup for a long time and basically tasked me to figure out what's wrong with it. When the sub is set to auto or on, it makes a very audible buzzing / humming noise. When hooked into an AVR and turned on and set to do test tones, nothing happens. It'll still do the humming with no changes to the bass response. I've tried playing DTS testing videos including LFE, movies, games - nothing from the subwoofer other than the humming. I don't know what I can possibly do as it was an extremely good sub and it's upsetting to not know what's wrong with it. Any advice or guidance would be really appreciated.} I will say I have tried using both the L/LFE port and the R port hooked up to the AVR with both not resulting in any bass response.