You meant to say "distance" and not "crossover" is way off, right? If you meant both are way off, what was the xover chosen on the sub? Remember to keep the LPF or whatever at 120hz, even if the sub xover is at 80hz (because xovers are not brick walls, and the .1 LFE channel can have info up to 120hz).
For your distance, leave it be where it was before. This is an extremely common misperception among first time users. It is accounting not just for physical distance, but also electrical distance, such as DSP or other filters your subwoofer has (and they all do). The distance measurement is extremely accurate, with a tolerance finer than 0.1 ft, however the true number will not be released by Audyssey/Chris.