Chasing a radio fault

[Kaz_]

Hi everyone,

2007 ibiza has a problem with the radio. Bought a single din pioneer to replace the old stock one. First few days of using it, it blew the unit. bought a new one, and this one keeps blowing the 5A fuse from the fusebox (radio one is fine). It seems like every time I increase the volume with bass, it pops.

Any ideas what that could be? I'm lost. Poor ground? Something shorting? Any ideas welcome before I start stripping the crap out of the car.

Thanks