Hi i recently purchased a 2004 legacy outback wagon which i love so far. I bought the car with an after market head unit. That radio turned on but there was no sound from any speakers. I bought new head unit for one that was better wired it up and same issue! Power and all functions work but no sound!!. i checked to make sure there were speakers in the car and there are
Any help would be appreciated!

what am i missing?! is there a factory amp hidden somewhere that may have died?