On Sunday we played a benefit gig for a family that had a premature baby and lots of medical bills. The gig followed a motorcycle poker run that also was a fundraiser for the family. The hall we were in is pretty large (at least 50' x 150' with 200-300 people in it), and I was concerned about my ability to fill it with two a new amp and speaker cab, neither of which i had used in public: a Behringer BX4500 amp (not real worried about that one) and a Peavy BX115 single 15" cab. What I learned was......I didn't need to worry! The Peavy cab performed just fine (cripes, the stage was flexing underneath it when I hit it hard) and I never needed to turn either the input or master output up past 30%. I had a massive amount of overhead room in that amp, and the speaker sounded just like a 15 should: fat and powerful. That single 15 was plenty to fill and potentially overfill that hall. At some point I may add a 4x10 cab for an option with more definition in the sound, but that 450 watt Behringer is one kickin' amp...I think it's gonna be juuuuust fine.