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

Showing 2 responses by eldartford

There is some theoretical effect (could be improvement or degradation) due to bi-wiring. It relates to the small signal that exists at the common (-) terminal of the speaker as a result of the impedance of the speaker wire. If you don't bi-wire, the tweeter signal is referenced to the voltage at the low end of the woofer, which may be slightly different from the voltage (ground) at the amp. Because the woofer is a complex load (not purely resistive) this error signal is not just an attenuated version of the music signal.

All this is just theory, but it is the only scientific reason that I have found to suggest that bi-wire has any effect at all. Note that it suggests that only the return wire (-) needs to be doubled up, and also that use of very heavy wire will eliminate the effect (resistance goes to zero). In fact, this effect may explain why heavy wire sounds better for a mono-wire connection.

If one were to experiment with bi-wire, I suggest that you use very small wire (say #30) so as to aggravate the effect (when mono-wired) enough to be clearly heard.

PS: My Maggies are bi-wired. It was an experiment, using #24 wire for the tweeter so as to replace the 1 ohm tweeter padding resistor with cable resistance. It's hard to say if there was an improvement, but certainly no degradation so I have left these wires in place.
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).