1992 Nissan Sentra 1992Nissan electrical problem

So my problems first started when I drained my battery I have a pioneer 760 amp hooked up to a10 inch sub.I basically drained the battery while parked listening to music while car was shut off. Battery died bought new one and checked alternator which failed replaced that too everything was ok for a few days but interior lights are dim bat light and brk light came on and my tach is going crazy sometimes it works sometimes it doesn't phrase help doesn't affect how the car runs but I don't want to risk it thank you