[Devils41]

So I have tried to search on forums and groups about anyone that's had their Subs go out. This is not the intermittent issue where the subs stop working and when the iDrive system cycles it will work again. I've let the car sit overnight, restarted the idrive and played all around with devices, settings etc to get the Bass to work. Its been about 2 weeks now with no bass from the subs.

I tried the dealer but I'd rather ask here on possible fixes/ things to check before spending $180 just to diagnose. Thanks in advance for any help or advice on possible things to look at before taking it in.