Why does my car drive rough and sputter up to 3000 rpm and drives fine after?

then it would shift and go bak down to 2000 rpm and drive rough until 3000 rpm. It is a 1998 acura integra ls and it used to have subwoofers in it. Everytime i turn the AC on the rpm will drop and when i used to have my sound system, every time the b hit, the rpm would drop alot too