[sci.electronics] Bi-Wiring Question

heath@shumv1.uucp (Heath Roberts) (03/14/90)

The bi-wiring philosophy seems to indicate that small wires carry high
frequency signals more clearly than large wires, and that large wires
are more conductive to bass frequencies. So you connect the small wires
to the tweeter, the big wires to the woofer, and connect them to the
appropriate passive crossover outputs (the crossover is at the amp
instead of in the enclosure). 

I've also seen this done differently--the crossover's back in the
speaker, and both sets of wires are connected to the same terminals at
each end--you just have large conductors in parallel with small ones.

I'm also a EE, and I've never heard (that doesn't mean it doesn't exist
by any means) any engineering argument as to why it works. But people
with "the golden ear" claim that it provides a fuller bass, crisper
highs, and smoother midrange. Some of the same people say that putting
armor-all on CD's allows you to read those bits more clearly (it helps
the laser decide if that's _really_ a one, or just almost a one, or
maybe it's a 2...) If I didn't know better I'd almost be inclined to
believe that audio was an analog signal... :) I have a friend (and he's
an excellent musician) who swears by both of these techniques (bi-wiring
and armor-all.) He also has AWG #12 wire connecting his CD player to his
preamp to lower signal resistance...

Bi-wiring is different from bi-amping (or tri- or
whatever-you-can-afford-amping) which is used often for large high power
systems (before anyone starts telling me how their 500W per channel
system works just fine with a single amp, let me inject that I'm
speaking of stage systems with several thousand watts of output power.
That's what I mean by large) What you do here is split the signal at
line level with an active crossover (bandpass filters) and send each
frequency range to a seperate amplifier, which is in turn wired
independently to it's own set of speakers. This eliminates the power
losses associates with passive crossovers at speaker level, provides
some power limiting, and lets you use most of your dollar/power for the
low frequencies, where you need the most power to attain a give SPL. I
don't know that multi-amping inherently sounds any better--you should be
able to EQ either type of system (multi- or single-amped w/ crossover)
for a flat response--but multi-amping _is_ more efficient than using a
single amp with passive crossovers.



Heath Roberts
NCSU Computer and Technologies Theme Program
heath@shumv1.ncsu.edu