Usually, you'd run the signal through the preamp into the active crossover and then to amplifiers powering the respective bass and mid/treble sections of the speakers.
Some folks like to run the satellites full range and use the crossover only to the subs. If your preamp has two sets of outputs, this is easily facilitated. You just run one pair of the preamps outputs to the amp feeding the maggies (bypassing the Marchland entirely) and feed the other pair of preamp outputs to the Marchland and into the amps powering the woofers. With Maggies, I'd probably opt for this configuration as long as I had enough amplifier power to feed the panels. If not, I'd use the high pass section of the active crossover to keep bass frequencies from being sent to the Maggies.
You will have to experiment with the crossover's settings and level controls to get the best blend of woofer to Maggie.
Some folks like to run the satellites full range and use the crossover only to the subs. If your preamp has two sets of outputs, this is easily facilitated. You just run one pair of the preamps outputs to the amp feeding the maggies (bypassing the Marchland entirely) and feed the other pair of preamp outputs to the Marchland and into the amps powering the woofers. With Maggies, I'd probably opt for this configuration as long as I had enough amplifier power to feed the panels. If not, I'd use the high pass section of the active crossover to keep bass frequencies from being sent to the Maggies.
You will have to experiment with the crossover's settings and level controls to get the best blend of woofer to Maggie.