Bose does not get a lot of love around here so other than calibrating your audio for the listening environment as best as you can, there's probably not much you can do other than replace the Bose with a higher quality receiver and speakers.
Carpeting, wall coverings, furniture, room size, etc. can dramatically affect the listening environment. Listed specs can only go so far because you don't know what the conditions under which the specs were obtained are. Your ears are what will determine what sounds good to you and if you understand room acoustics, you know that what you hear in a show room can be quite different once you get it home. Speaker placement can also affect what you hear to a degree.