Magnepan MG 20.1 - Manual (Page 7)

D. Bi-Wiring Option. Bi-wiring requires two sets of speaker cables.
They may be identical, or one set may be specialized for high frequencies
and the other specialized for low frequencies.
1. Remove both jumpers on the XO20.1 Crossover.
2. Connect one set of cables to the low cable input and the other set
to the high cable input. Connect the other end of the cables together
(observe +/- polarity), and connect to one channel of the amplifier outputs.
If frequency specialized cables are used, connect them to their respective
inputs. In either case the other ends are connected to the same amplifier
channel.
3.
Repeat same procedure for the other channel.
11. BI-AMPLIFICATION
The MG20.1 is conveniently arranged for hi-amplification. To hi-amplify,
two stereo amplifiers (four channels of amplification) and an electronic crossover
are required. For hi-amplifying with a conventional electronic crossover, connect
the system as shown in Figure 2.
Set the high pass section at 200-300 Hz, 6dB per octave. Due to standing
waves at the crossover frequency, the low pass section may require adjustment
from as low as 90Hz (12dB Bessel) to 150Hz (15dB Butterworth). Typical
settings are in the middle of this range. Optimization of the low pass can be done
by ear (with music) or spectrum analysis.