REW and Omnimic are simply more accurate, fully featured measurement systems that greatly improve upon the included minimalist on-screen display measurement facility found in your SMS-1. Much like the that the SMS-1 offers but more accurate (less pretty looking results!

), REW and Omnimic allow you to see the problems more clearly and that combined with a more thorough understanding of the subject matter allows you to better isolate the source of the problem so as to address it properly. Based on what you see, you can adjust placement of subwoofer and loudspeaker positions, set individual delays, and then manually apply parametric EQ to tidy up the remaining problems. All the pro audio loudspeaker processor/EQ boxes I mentioned are about the same size as your SMS-1. The measurement systems use a mic much like your SMS-1, but the measurements are taken by your computer and displayed there rather than on your tv screen.
Oh BTW, if you were using the SMS-1's auto EQ function- STOP THAT RIGHT NOW!

It works crap compared to manual operation.
Happy Trails!
MTB Vince