How to connect bi-wire speakers

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.

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.

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?

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

When those engineers and professors discuss waveguides and their implications in audio cables, they usually just show characteristic impedance, LCR filter effect losses, impedance losses, etc. They rarely mention phase effects, group delay, etc, and I've never seen any mention of the interaction between the electromagnetic wave traveling at a few meters per second in the conductor material, and the electromagnetic wave traveling at nearly the speed of light in the dielectric.
This article is a "readers digest" version which discusses much of this and has been printed in Stereophile and HiFiNRR in the UK:
http://www.essex.ac.uk/ese/research/audio_lab/malcolmspubdocs/G3%20HFN%20Essex_Echo_(cables_1985).pdf

Here is a much more in-depth and technical paper (long - 12mb):
http://www.essex.ac.uk/ese/research/audio_lab/malcolmspubdocs/G6-9%20Unification%20(4%20parts).pdf

Best Regards,

Jeffrey Smith
Silversmith Audio

Jeff,

Can you point me to a specific paper as there are more than thirty listed at the URL you gave.

I agree wholeheartedly that all these concepts are in engineering textbooks, at least they were twenty years ago. I am not questioning any of these engineering principles.

However, waveguides and effects such as you describe have long been regarded (by most electrical engineers and professors that I know) as having negligible impact to the signal at audio frequencies and cable lengths (meters not kilometers) used in most hi-fi system configurations.

It is the application of these theories to the range of audio frequencies in the configuration of a typical hi-fi system where I beg to differ/question whether they can have such a large affect as to be one of the worst offenders.

Thanks to point me to the specific paper that shows a binding post (or cable) can be the worst offender.

As an engineer, I will simply state that the concepts and equations behind my statements can be found in any text on electromagnetic theory, and, surprisingly, are pretty simple.
The Director for the Center for Audio Research and Engineering, and Director for Postgraduate Studies within the Department of Electronic Systems Engineering at Essex University in the UK, has written articles which very neatly explain how a binding post can dramatically affect sound quality. While these papers are more specifically about cables, the same concepts apply to the binding posts as they are just a continuation of the conductor chain. Many of his papers can be found here:
http://www.essex.ac.uk/ese/research/audio_lab/malcolms_publications.html#PhD%20Thesis

Hopefully some of those articles can answer your questions. Happy Reading!

Jeffrey Smith
Silversmith Audio

Briefly, binding posts are one of the worst offenders in terms of audio degradation (thick metal and its affect on the electromagnetic wave as a waveguide).

Having studied power transmission lines, EM radiation, waveguides and electronics, I would simply like to point out that most electrical engineers (that I know of) would disagree with the above statement (when dealing with signals at audio frequencies).

I am not disputing the fact that many people are convinced that they hear something different...I just beg to differ on the scientific explanation.

As far as science is concerned (to my best knowledge), one should not expect an audible difference from any of the commonly used binding posts (provided a suitable connection is made).

Describing a binding post as "one of the worst offenders in terms of audio degradation" is a patently false statement (IMHO).

Hi Edmond,
They only way to avoid passing the signal through two sets of binding posts is obviously to use a second set of high quality cables to bi-wire. In the case of Silversmith Audio cables, there is nothing wrong with using Silver cables for the bass and Palladium cables for the mid/tweeter. The best sound of course will be achieved by truly bi-wiring with Palladium.
Upgrading your jumper to Palladium will also improve your sound quality, though not to the level of bi-wiring.
Lastly, consider upgrading your binding posts, if possible. Low mass binding posts are finally hitting the market and I recommend the Eichmann product. This can be a substantial sonic improvement to both the single and bi-wire configurations.

Best Regards,

Jeffrey Smith
Silversmith Audio

Hi Jeff

Thanks for your description, it will clear and benefit for many people, but how can we get the most good sounding without losing the deep bass, sound stage and focus? should I get other pair of speaker cables for bi-wiring?(but it will cost so much), or use Silversmith jumper would help? please comment.

Best Regards

Edmond

Briefly, binding posts are one of the worst offenders in terms of audio degradation (thick metal and its affect on the electromagnetic wave as a waveguide). When connecting a bi-wireable speaker with single wire cables, signal must pass through two sets of binding posts and, typically, an equally poor jumper, before it reaches the drivers. If the single cable is connected to the bass posts, one can expect diminished focus, soundstage, and a glare in the treble region with poor high freq extension. On the positive side, the bass will be tighter (less boom) with better perceived bass extension (deeper bass). If the single cable is connected to the tweeter/mid posts, one can expect a more natural top end, better imaging and soundstage, but more boomy (out of control) bass. Many actually enjoy the bass boom and prefer this configuration. The magnitude of these differences will depend on the crossover point and the quality of the cables. This is an easy experiment for anyone to do in their own system to hear the effect for themselves.
Again, feel free to call for a more detailed explanation.

Best Regards,

Jeffrey Smith
Silversmith Audio

Silversmith,

"Rlwainwright, please feel free to call me if you would like an explanation about sonic difference between attaching the cables to the tweeter or bass posts."

Jeffrey, maybe you can give us just a brief description for why it makes a difference, as many could benefit without having to call.

Greetings Edmond,
Obviously the connection you described will function, but it will be inferior sonically to connecting both cables to the tweeter terminals. It may have simply been easier to connect the cables the other way because of the way the cables were situated, close spacing of the binding posts, or to have the least tension on the ribbons.

Rlwainwright, please feel free to call me if you would like an explanation about sonic difference between attaching the cables to the tweeter or bass posts.

Best Regards,

Jeffrey Smith
Silversmith Audio

RW,
jump the + to the + & - to the - not "between the + and the-"

>> NO-o-o-o-o-o!...Speaker cable either to tweeter terminals (+/-) OR to woofer terminals (+/-) <<

Gee, I thought this was *exactly* what I recommended. Obviously, I wasn't clear in my explanation. My bad, sorry. Let's suppose you have this configuration:

"Upper" terminals: +_______-

"Lower" terminals: +_______-

The jumper can go between the + and the - of either the "Upper" OR the "Lower" terminals. The speaker cable would then go to the un-jumpered terminals.

As for *requiring* the jumper to be on the bass (or, usually, Lower) terminals - *why* is this necessary? I fail to see how it makes ANY electrical difference.

If Edmond has 2 sets of cables for each speaker (with each set being a +/- pair), he should go ahead and bi-wire 'em.

If you want the *final* word on this, ask the speaker mfgr., I'm sure they've fielded this question before...

Flame suit on...

-RW-

Hi

Thanks for everyone, my speaker cable is single wire Palladium. As I saw someone connected one cable to the bass binding post, and one cable to the tweeter binding post. Do you think that would be better connection than both cable connect to tweeter binding post? Both connected with jumpers

Edmond,
The best sound will be achieved by attaching the speaker cables to the tweeter binding posts and connecting the bass posts via the jumper. If you, instead, connect the speaker cables to the bass binding posts, your sound will be noticeably degraded. Please feel free to contact me if you have any questions. By the way, Silversmith Audio also makes jumpers.

Best Regards,

Jeffrey Smith
Silversmith Audio

"If the cable is not a bi-wire, you should place your jumper between the negative and positive terminals of either the tweeter or woofer. It doesn't make any difference which ones are jumpered, just be sure to place the jumpers on the same "type" of terminals (tweeter or woofer)."

NO-o-o-o-o-o!

Speaker cable either to tweeter terminals (+/-) OR to woofer terminals (+/-) OR to one tweeter terminal (+/-) AND one woofer terminal (opposing leg of +/- from that of tweeter terminal).

After you have sorted out this six-and-one-half-dozen scenario connect the jumpers to tweeter/woofer terminals (+/+) AND tweeter/woofer terminals (-/-).

Otherwise you may have smoke coming from the amp and no sound (with the exception of small exploding sounds).

Good luck!

Edmond,

Is your cable a bi-wire? If so, simply connect the 2 negative leads of the wire (usually marked black) to the negative terminals on the speaker and the positive leads (usually marked red) to the positive terminals.

If the cable is not a bi-wire, you should place your jumper between the negative and positive terminals of either the tweeter or woofer. It doesn't make any difference which ones are jumpered, just be sure to place the jumpers on the same "type" of terminals (tweeter or woofer).

One other thing, as long as both speakers are connected in the same way to the amplifier, they will remain in-phase. So, it doesn't matter whether the gold speaker terminal is positive or negative, just make sure both speakers are connected identically.

I hope this is clear. If not, I'll try again [smile].

-RW-

I would connect both +&- of the Silversmith to the high frequency terminals, and then the jumpers from there to the low frequency terminals. Why? High frequency information is more likely to suffer (i.e., detail) from added connections and wire than the low frequency.