I was worried this amp wouldn't be loud enough. I was worried about nothing. This thing is LOUD. I used to run a Presonus Studio Channel into a Crown XLS1000 power amp. I ran the Crown in bridge mode which supposedly puts out 1100W. I have a Hartke 4.5XL which is ~400W @8 ohms. I would always have to crank the Crown to a few notches below max to compete with my guitarist. Did a decibel reading on the iPhone this morning. Cranked at normal gig volume (i.e. almost at max) the Presonus/Crown was peaking around 109 dB with an average 103 dB. Plugged the GK in, contour presence and boost at zero, eq flat, input volume at 11-12 o'clock and woofer (master volume) at 12 o'clock. Peaked around 111 dB with an average of 103 dB. Without even breaking a sweat and with no clipping/distortion. This unit puts out 320W @ 8 ohms so I could safely crank the woofer all the way without pushing the cab too hard. I don't think I'll ever need to be that loud. I am beyond impressed and happy with this choice of amp. There really is a difference between normal watts and "GK watts".