I wasn't a bit surprised. It is reminiscent of my decision to adjust my crossover settings when I discovered a dip in room response that affected my mains. There was no way to EQ my mains, but by kicking the crossover up one notch I was able to pass the burden on to the sub and then EQ the dip out of existence. Same deal as you found - no ear I know is going to listen to a system and say "there's a dip at 56Hz that you need to fix" but the SMS-1 made it crystal clear.