W211 Audio 20 Replaced by Aftermarket Alpine - SQ issue

[atitudejim]

I have this weekend replaced the original Audio 20 headunit for a alpine 9853 headunit which i had on my old car as i have ipod connection.

Got it all fitted works fine... But... the sound quality is quite low compared to the audio 20, i assume the audio 20 has a built in amp and runs better the speakers without distorting on bassy tunes...

has anyone had this issue? any ideas?

Thanks