Cobalt cable theory on bi-wiring. Fact or fiction?


The follow was taken from colbalt cables web site. I was just wondering what those with more knowledge and experience think of this theory? If the theory is sound, it will save alot of people some money for more component upgrades. "Bi-wiring is a technique becoming quite popular in speaker applications. However, in our opinion, there are only a few situations where bi-wiring makes sense and MANY situations where bi-wiring is just hype. Here is what we think the complete story is about bi-wiring, and why it really does not make any sense for most people's equipment. The simple explanation for why the advantages of bi-wiring are very slight or nonexistent is that most people only have speakers built for bi-wiring, while their amplification is not. By using the same amplifier channel for both sets of bi-wire cables (both sets are connected to the same binding posts on the amplifier or receiver), the same electrical path is being used for both sets of terminals on each speaker, thus negating the core advantages of bi-wiring.

For example, most bi-wireable (we invented a new word) speakers come with some sort of plate or bar that connects the two (+) and the two (-) terminals (one for high frequency and one for low frequency) to each other. By using these plates or bars, you are "bridging" the two sets of terminals together creating only one connection point, so that you only need to make one speaker connection to each speaker.

By using the same amplifier channel (and terminals) for each set of bi-wire terminals on your speakers, you would be bridging the two sets of terminals together with your amplifier (since they share the same connection point on the amplifier). From an electrical perspective, this is NO different than running one speaker cable to the speaker, and bridging the two sets of terminals together with the bar or plate.

But wait, there's more! If you act now... (just kidding).

The only advantage in most setups (only speakers built for bi-wiring) for bi-wiring would be using twice as much physical wire (two separate runs to each speaker, thus dropping three gauge) as a standard wiring configuration.
However, if you are already using a fairly low gauge speaker cable (like our 10 AWG Ultimate Speaker Cable), there is little to be gained by "doubling-up". Plus, the added expense of running twice as much speaker cable for a barely audible (at best) difference, probably does not make too much sense.

The funny thing is, bi-wiring is actually a sound theory (pun intended, HA!), but the advantages can really only be had when it is used in conjunction with bi-amping (running more than one amplifier channel per speaker). In order to bi-amp the "right way", an external crossover between the preamplifier and each amplifier channel will be needed (so that only the high-frequency or the low-frequency parts of the signal will be amplified), and the internal crossovers inside the speakers will need to be disconnected (so that each amplifier will go directly to the corresponding speaker driver, i.e. the woofer for low frequency and the tweeter for high-frequency). WHEW! We personally don't know of too many people who will go to these extremes to take advantage of the benefits of bi-wiring, so bi-wiring just ends up getting WAY more attention than it should. We think that you should know what some of these other companies are up to out there. Straight-up and at ya partner."




dbx
Zoya, it has always seemed to me that for your position (sorry to refer to it that way, I know it's not an original idea with you) to even stand a chance of making any 'sense', one must first buy into the proposition that in a biwire setup, the amp will somehow discriminate between which frequencies it sends through which cables - *and* that the so-called 'back-EMF' generated by the woofer will decline to find its way into the cable connected to the tweeter upon its arriving back at the amp's output terminals, even though at that point the two sets of cables are in intimate contact with each other.

I don't buy any of that, although I freely admit I'm not technically competent to scientifically evaluate all the arguments (much less Eldartford's post :-) It seems to me that even in a biwire setup, the tweeter and woofer sections will still 'see' each other - plus both runs of cable, whether or not the two runs are endowed with differing physical/electrical properties - within the overall amp/cable/speaker circuit.

Speaking of Eldartford, until recently I wouldn't have though twice about his passing comment on heavier-guage wire sounding better, all other things being equal (whether that was achieved through biwiring or simply employing a heavier single run). But that was before I brought in a set of Audience's Au24 SC for audition, wherein the wire for both legs of the connection plus all the dielectric and jacketing materials are bundled into a cable exactly 1/8" thick, or about the diameter of your average computer mouse cord. I think all the positive notice this product has been receiving is probably justified, and Audience's theory here, as I understand it, is that AC resistance, which they equate with inductance, is most important (along with capacitance) to minimize in an audio circuit - as opposed to DC resistance - providing that the wire guage is sufficient to handle the current-carrying demands made upon it.

I'm not qualified to speculate on Audience's theory of their product's operation, but though I'm still not finished in my testing, I can tell you that compared to my reference Satori SC (a fine cable - maybe even preferable for those seeking warmth - next to which the puny Au24 looks simply comical), bass response does not seem to have suffered (though its presentation is different), and top-to-bottom clarity and overall temporal integrity seem to have improved. (I should note, however, that my most positive impressions have been with the cable mated to my reference VTL tubed amps ; when I initially did this comparison using a McCormack SS amp and the same speakers, I thought I preferred the Satori overall, but I need to revisit this issue now that the cables are more fully broken-in.)
Zaikesman...True that Impedance (not just resistance) matters. However, low resistance is a big step in the right direction, and much easier and cheaper to do than Inductance minimization.

I still think that the best approach is to minimize everything with wires about one foot long! (Monoblock amps).
I will not even attempt to participate in the technical analysis of the merits of bi-wiring. What I want to add is that I can definitely hear a difference, and - yes - I have participated in 'blind' listening experiments to confirm this.

Of course, one cannot argue with those individuals that state that they can't hear a difference. If bi-wiring doesn't improve your sound, then don't spend $$$ to do it!
I don't buy zoya's theory for a minute. The frequencies we are talking about are so low that the wavelength of the signals is about 10 miles long. (3*10^8/20*10^3 = 15000 meters).
Therefore all points on the cable are at the same voltage, and see the same impedance, whether you biwire or not. I bet you could not measure the slightest difference between the signals at the HF and LF terminals when biwiring off a single amplifier.

The only time an amp sees different impedance is when you biamp, because it's only driving one part (HF or LF) of the speaker, and so the impedance curve to each amplifier is likely to be much more benign.

Biwiring without biamping may help in that there is simply more conductor, but I don't expect any effect beyond this.

A theory is NOT a theory until proven true. Otherwise, they are called hypothesis or conjectures. Too many unproven claims are put out there to lure unsuspected consumers.