Linn LK140 Owner's Manual page 12

For more performance, you can use two or three LK85/140s to
bi-amp or tri-amp to the loudspeakers, each amplifier driving the
bass, midrange, and treble signals separately.
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When bi-amping or tri-amping the highest possible performance
can be obtained by removing the passive crossover units from the
loudspeaker and fitting active crossover modules to the LK85/140
to accurately divide the signal into the appropriate frequency
bands. This is known as active playback.
The LK85/140 is designed to be easy to convert to active playback.
A complete range of stereo active crossover modules is available
for all current Linn loudspeakers. Your retailer can fit these and
make the necessary changes to your loudspeakers to transform
your system to fully active.