No bass on the individual audio

[benjii]

Helo guys

I have a BMW X6 with the "individidual audio". When i got the vehicle(shippe over seas) there was no bass whatsoever. (I have adjusted the bass settings and surround off, on. Used CD, FM, AUX and bluetooth.

I've searched around alittle and i understand it could be the amp or that both of the subs have cutted!

I have also read that if the battery is low, it may cut the amp and comfort accees. (It has been in shipment for 3 weeks) but the vehicle started without any hassle. I havent been able to drive the car after i picked it up from the harbor since it not registered yet and doesent have license plates

Is there any way to troubleshoot to figure out what is causing the problem?

Thank you very much