Hi, I have realised my rear speakers are not as loud as the front ones. I do not have a Bose set up, so I am considering changing all speakers to aftermarket ones. Does anyone know why the rear speakers are not loud as the front ones, by this I mean when I have passengers they cannot hear the music. I have checked all the settings via my headunit- all seems to be fine. Also, any recommendations for aftermarket speakers? Thanks in advance.