OP: without even knowing what your system is I can say that it is very very likely that you can improve your system to get closer to the max potential of even 16/44 music. It is even more likely that such improvement will come from bettter performing speakers and improvements to room acoustics. This is where most chances of improvement are.
until then, thinking of hi-rez is a waste of time. After then, it is a waste of time, too.
Unfortunately, hi-rez music is not equal to better sound.