Again and the last, you amp/filter or anythings like that ( i don't see the device) have drain your battery because of bad installation.
For know exactly the damage is : make the car run without battery plug in (unplug after start) if the car can run only on alternator replug the battery unplug everything related to the radio , charge the battery and return to the shop install your stuff .... is no more complicated than this.
this is my free advice, witch i will charge you 300 US$ if you come to my shop and ask me to sort out your problem. You can keep turning and thinking, reading article over the web they is write here from yesterday
