Threshold and Magnepan

My audio mentor back in the day- Jay Dial- drove Maggies to bliss with Threshold. You should be quite happy.

Mr J- Personally, I used a Dahlquist DQ-LP1(slightly modded) for bi-amping planars(Acoustats and Maggies) in my systems for about 25 years. They are still available on the used market and very popular. See page 13 of this newsletter for a little info on it: (http://www.avahifi.com/root/audio_basics/ab_pdf/ab1989.pdf) Of Course- That would require a separate powered sub, or amp & sub which may be more than you want to deal with. There are self-contained subwoofers out there that provide a means to adjust for the phase shifts that occur when the subwoofer is placed out of time alignment with the mains. Without that ability, your imaging, sound staging and focus suffer greatly.

Marchand XM-44 is a very good x-over, you will need a fast sub to keep up with the Maggies. Rel subs are known to work well with Maggies.
Check out to Planar forum on AA.