I agree with M&K, Nalod - the crossover in the sub originally appeared because receivers didn't perform any bass management. Once receivers and processors began providing effective bass management (something that Outlaw has put a lot of emphasis on even back in the days of the Model 1050), the sub's crossover isn't needed.

With a well-chosen crossover point, some care given to phase (the EP-500 offers 0 and 180 degree settings), and a little fine-tuning of the sub trim setting, you should be able to get a smooth integration of sub and mains even without a device like the SMS-1. Using that approach, I have been able to integrate my sub with speakers such that I didn't have to tinker to get positive results. With my old sub (an SVS 25-31PCi) and old house, I had to lower the mains crossover to 40Hz to achieve that, as 60Hz or 80Hz crossovers yielded too much boom in music. With our the den of our new house and the LFM-1, I was able to get a great integration of sub with speakers at a 60Hz crossover.

The SMS-1 will simplify this process by offering greater control over the phase (15 degree intervals) and by providing visual aids (frequency response graph up to around 200Hz). Check out the Outlaw Guide for some idea of what the SMS-1 does for you.