Only front side speaker working

[Aha]

Hi i recently bought an e92 m3..
and the problem is when i listen to music sounds like only front speaker works.
if i change the fader all the way rear only the speaker under rear window works.
the 4 speakers on the rear seat doesnt work at all.

and when i turn the music loud the front right speaker keep making blowing sound(really noisy)

will this be cuz the logic 7 amp died?