OK,...Assuming that the battery is new & the pickup heighth is set properly; It's an active bass. Don't turn everything all the way up like on a passive bass. Turn the master volume all the way up, on the active EQ, find the detent (knotch) in the middle. That's flat. From there, you can boost/ cut/ whatever. On your amp, if it has a little button or switch that says -12db or -15db, push it IN. Pad it down. Most active basses have a bit hotter output than that of a passive bass. There probably isn't a thing wrong with the bass. It just sounds like a minor misunderstanding of gain structure. Check out your amp & cabs too. Be sure your speakers aren't blown.

