but nothing coming from the rear.
Well for a start that is entirely wrong. Unless of course you are out in an open field. There is always going to be sound reflected from the rear wall. You are just not aware of it.
That is exactly what Dolby surround creates from a stereo (so sorry, stereophonic) source. (Yes that bracket is sarcasm!)
Music is far more critical than movies, so you'll need a superior system. Start with similar speakers that produce a similar sound and all channels critically balanced.
If there is any harshness from the speakers, it will be even more evident with additional speakers. Perhaps that is the reason millercarbon called home theatre sound crap (his word, not mine).
It takes a lot of effort, but when you get there it was worth it.