I experienced this today.
I had my aftermarket subwoofer out of my car for an autocross. So I was listening to the system stock. Suddenly all the bass dropped out. I was listening to it at medium volume. My EQs are set at the middle.
I'm pretty adept with car audio so when I got home I checked a few things. I suspected an amp problem but that has been eliminated because when I plug in my aftermarket sub there is still plenty of signal going to the LC2i. My sub sounds fine.
I pulled out the harness from the EPS amp and used a multimeter to check the subs resistance. It gets no reading.. no continuity, no resistance. I'm not sure if that means a blown sub or not honestly.
I'm not sure if both subs went out at the same time or if it was one at a time. I do faintly remember moving the balance from left to right a while back and thought the bass may have only been on one side. Not positive though.
I don't have a Torx 50 bit for the seats so I will wait to get one tomorrow and pop one of the subwoofer enclosures out and check the sub. Seems odd though. I never heard any distortion, don't crank the bass since I have an aftermarket sub, and was listening at relatively low volume when it went out.
I almost wonder if there is a connector that came off of the stock sub or something. Maybe a connector came apart? No resistance reading, no problem with the amp, no distortion, etc, then suddenly no bass? What is going on here?
Sounds like no one has had any luck until the subs are replaced. I imagine they are the culprit, but who knows. I am certainly not a stereo abuser so I am confused.