I play a passive jazz and am just getting into live sound. Our church just got a new PA system and the band is wanting me to go direct so we can mix the sound. However, we don't have a sub in the system. I have pretty much learned that I need an active DI box but I'm not exactly sure why? We have a passive DI box for the Keyboard and I can plug into that and can play though the system. With that being said, it is kind of shallow and is nowhere near the sound from my Ampeg rig. Will the active DI box make a noticable difference in the tone throught the system or is it more of a fuction of not having a sub in the sytem. Thanks for the help.