How to connect bi-wire speakers

Jeff,

Thanks I managed to get the first link ( even though it was a little garbled on the thread )

In case anyone else is following this, it should read

http://www.essex.ac.uk/ese/research/audio_lab/malcolmspubdocs/G3%20HFN%20Essex_Echo_(cables_1985).pdf

I fully agree with the discusion and math starting from Maxwell's equations ...who can argue with that!

I also agree with the calculations in terms of the math and the application of wave propagation theories to highly attenuative media like copper. There is no doubt that these losses and distortions do occur.

Again where I beg to differ is the magnitude of these EM effects in relation the very large primary signal.

The numbers suggest that the secondary distortionary effects of EM field propagation generated by the current flow in copper media can be ignored compared to the size of the primary signal (current flowing down a cable and responding principly to LCR lumped circuit theories, current being a bunch of electrons)

Nevertheless, your references and material is very interesting and I plan to read up more on this subject and the links you have provided. Definitely Happy Reading there! Thanks

Shadorne, I think you've hit the nail on the head! The key to all of this is the phrase "at *audio* frequencies". Jeff brings up the group delay bugaboo but fails to mention that this delay is on the order of only a couple hundred nanoseconds between upper and lower frequencies in a typical speaker cable length (say 8ft.), with upper frequencies arriving sooner.

In addition, this difference amounts to changing the placement of the tweeter 16 microns behind that of the woofer. Wanna bet you can't measure that difference in any practical way?

Rlwainwright,

Your understanding matches mine. IMHO up to 2 Msec of delay between drivers is what most pros believe is below audibility... so most speakers are designed with this in mind. Generally a smooth phase response is desired rather than pure minimum phase...smooth phase may be important to preserve timbre.....but 2 Msec is a far cry from 200 nanosecs. There is a lot going on in a speaker and cross over network ....far more effects on phase than in a cable. Active designs usually have better phase response than passive designs but are still far from perfect. With so much going on in the speaker I don't lose any sleep about what is going on in the speaker cables. I may be completely wrong on all this... but that is my interpretation of the physics behind this stuff.

Still - all else being equal - it would appear that since you have to make a choice of which set of posts to connect a single wire to then the mid/upper would be the right ones, as Silversmith suggests. At a minimum, there may be no "audible" difference, but to whatever degree there is a binding post effect, it's being minimized.