A good number of hardcore Maggie owners tear into the crossovers that Magnepan installs in their speakers, especially the guys who frequent the Planar Speaker Asylum.
One easy mod is to replace the stock binding posts with ones from Cardas; the Cardas posts fit in the stock holes with no problem. While they have the back plate off the speaker, they bypass the fuse block (it contains parts made of ferrous material!), which may easily be accomplished by simply moving the round tin connector on the end of the internal connecting wire from the fuse block to the binding post, no soldering required. Of course soldering the wires onto the posts is even better.
The crossovers in most loudspeakers contain compensatory parts---parts needed to deal with problems inherent in the speaker’s drivers. Maggies don’t; Magnepan crossovers are simple "textbook’ filters (1st, 2nd, 3rd, or 4th-order. That’s 6, 12, 18, or 24 db/octave).
Owners of earlier Maggies (X1.6)---which have parallel crossovers (X1.7’s have series crossovers)---have the great option of bi-amping their speakers. Hook up the output of your pre-amp to the crossover, and use one amp for the woofer, another for the midrange/tweeter drivers.
I have a pair of Magnepan Tympani T-IVa (the precursor to the current 30.7), which came with an external crossover. But it is inserted between a single power amp and the Tympani’s, one of the crossover’s output jacks going to the two separate bass panels, the second set of outputs to the midrange/tweeter panel. That crossover contains two filters: a 3rd-order low pass at 250 Hz, and a 2nd-order high pass at 400 Hz. Running the Tympani’s in this manner is of course not bi-amping, and ignores one of the main benefits of bi-amping: removing bass frequencies from the signal the midrange/tweeter amp "sees." Removing them allows for more power to be available to the midrange/tweeter drivers (bass frequencies use up most of an amp’s output capability), and with lower distortion (thanks again to those darn bass frequencies).
In the Tympani owners manual, Magnepan actually encourages owners to bi-amp their speakers, using an active crossover. I have the great little active crossover First Watt used to offer, the B4 (get it? 
), which provides 1st, 2nd, 3rd, and 4th order filters in 25 Hz increments from 25 Hz to 6275 Hz. The B4 is completely discrete, no OpAmps or ICs. With the B4 a Tympani owner may not only enjoy the benefits of bi-amping, but also exactly duplicate the speaker’s stock crossover. AND enjoy the benefits of not putting the signal through the stock Maggie crossover.
By the way, Magnepan offers their flagship model---the aforementioned 30.7---in both Standard and "X" Series versions. Rather than spending the money on the upgraded version, I would instead choose to spend it on a good quality external crossover and second power amp. Unfortunately, the 30.7 contains a series crossover, not a parallel one. So to bi-amp it one must perform internal surgery. Not for the faint-of-heart! Not a problem with the Tympani’s---they all had parallel crossovers. In 1973 I bi-amped my first Maggies---the original Tympani T-I---with an ARC passive x/o and two ARC amps.
