Unless an amp isnt working properly there really isnt much you can do for it but an average bass can be changed and improved.To settle this go to Guitar Center,Sam Ash,Sweetwater and play a $300 to $500 bass thru the best best bass amp they have and listen to everything thats possible.Then pick up a $2000 plus bass and play it thru some cheap combo amp and listen.Notice that the $2000 to $3000 spent on the average bass/good amp combo wins everytime.Upgrade your amp 1st.Then you will know exactly what your bass needs.