I am almost done with my music room build in my basement. So far it is the following:

* 18' x 18' room
* Sound system piped through computer system and voice activated
* Drop ceiling for sound dampening
* Doubled circuits for power needed
* Keyboard setup
* Space for drum set
* Duel guitar setup

Question I have, What is best setup to use for wall covering to not make it sound like an echo chamber....but on a budget?