In article , Don Pearce
wrote:
On Sun, 18 Jun 2006 12:55:14 +0100, Glenn Richards
wrote:



The second point is that the tweeter and woofer are not in parallel.
Does that surprise you? This because we are dealing with signals in
defined frequency bands, and we have a crossover, which presents a
high impedance to the cable in the stopband of each driver. [snip]

Yes, except - there's an equivalent series resistor in the feed to the
"high impedance load". So a voltage drop across the LF *will* affect
the HF.


No it won't. Go read some theory on diplexing.

There may be some effect if the 'out of band' impedances are not suitably
high. However provided the cables and signal source have a low impedance,
etc, they are likely to be irrelevant in practice as they would be too
small to have audible significance.

As usual, it is always possible for someone to assemble a system with
extraordinarily inappropriate properties, but this seems unlikely to be an
issue with sensible cabling, etc, in a domestic audio system.

By bi-wiring, you split the signal before this "series resistor",
therefore a voltage drop across the LF cable won't affect the HF.

I think Don is trying to explain that this will also be the case with
conventional wiring given sensible cables, etc. With a non-zero speaker
resistance and conventional wiring the LF signals will alter the
speaker-end voltages slightly *at LF frequencies* - which the HF speaker is
supposed not to be reproducing, and for which the HF unit and network may
have a high impedance. Linear superposition is your friend here... ;-

I also think that both Don and Serge are pointing out that your approach is
too simplistic, and hence inappropriate and misleading.

Slainte,

Jim

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