The Disadvantage With Bi-wire



One thing that happens when you biwire your loudspeakers is that the input of the high- and the low-pass filters are fed
with different input signals. The difference is a result of the high frequencies and the low frequencies being forced to
travel different paths, perhaps through different types of cables, but under all circumstances through cables who have
seen different loads (a tweeter with a high pass filter has a completely different impedance response compared to a
woofer with a low pass filter!).

What happens is that the drivers will work less well together than when their filter halves were fed with equal signals.
The result is a generation of more static and stochastic phase error sounds at different directions from the loudspeaker.
The stochastic phase error sounds appear because there may be different types of unlinearities in the low- and
high-frequency paths.

What does this sound like? Well, usually, just as you may expect from physics, it appears as a change in the
reproduction of space and sound stage. Often, the first impression is that the "biwired" sound presents extended
"dimensions", more "air", and is more "living". The impression after a week or month, however, is that all recordings
sound very much alike, and the "airiness" appears on all records. It does not even sound like air anymore, instead more
like a slime that pollutes every record you play. No wonder, since it is not a real, recorded quality but a "speaker
characteristic" added to all reproduced material. "Sameness" is another word for it.

Picture 4: This simulation is based on the diagram of picture 3. Here you can see that a phase difference has
arisen when biwiring is used. The reason why the phase difference is largest just above the cross over frequency
is that the inductance of the cable resonates with the capacitance of the high pass filter when not the inductance
of the low pass filter is available in this range as when single wire is used. The most probable reason to the
capricious sound of biwiring is that on top of this steady state error another, transient induced phase error
between the cables will appear when playing music. This changes the radiation pattern of the speaker with the
music. The human ear is very sensitive to such phenomena.


Standard Member
Last weekend I switched from biwire to both strands of cable into one set of binding posts with the binding posts all joined with speaker cable. The midrange is defo better IMO so I'll never biwire a speaker again, 2 sets of binding posts should only be used for biamping.

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