Hi. To start, I really appriciate the helpful suggestions I am seeing in these forums. My situation is I am looking into getting a new head for my SWR rig. I have playing a bass 750 with a g3 cab for years (no probs, just not enough lows), but since joining a louder band I added a 15" sob cab to my rig (both cabs are 8 ohms). I'm now getting an unpleasant low-end distortion from my sob. I have the cabs running parallel with speakon cables if that info. matters. <p> Now here's my main question... I'm looking to either upgrade my 750 to a 750x (for the built-in overdrive) OR an SM-500. Which should I go with? Am I overpowering my sob with 750W? Is the stereo feature in the 500 better for this setup? Why does swr recomend the 500 for this setup- isn't it underpowering the cab? CONFUSED, please help.