Absolutely.

Either you trust them or not. If so, buy, if not, keep shopping.

Just my $0.02

Charlie

www.sonicdesign.se//biwire.html

BI-WIRE, NOT ONLY AN ADVANTAGE

A popular method to connect an amplifier to a loudspeaker is to use something called bi-wiring. The technical idea behind this special way to connect has not reached the public in other words than "better definition in the mid range", "the bass will be faster" and "the treble more in focus" or similar nonsense. The problems and faults that arise have not been mentioned, of course.

THE ADVANTAGES FIRST

The idea with biwiring is to connect the amplifier to the filter halves separately to prevent intermodulation, generated by one driver, to influence the other driver.

If you look at the damping factor that reduces the unwanted signals however you will find that they differ very little with or without cables (with 5 or 0 metre long cables for example). When using a tube amplifier, the cables in practice have no influence at all to damp the signals from one side of the filter to the other, because the damping factor is too low already in the power amp. The signal will slip through anyway to the other driver, despite the cables.

Apart from that, a well-designed crossover filter will provide a certain protection against "leaking" intermodulation since each half of the filter (in a two-way system) will damp each half of the frequency range.

Another point using double cables is the ability to choose separate cables that are especially suitable for each half of the frequency range. On the other hand, there are cables made along these lines without being double. (Monster, Isoda, MIT, and others) even if they do not work as the manufacturers claim, they have this in common, that for each frequency range, or level, they have different strand (different materials, areas, winding techniques and such) that are parallel connected. If you assume that the signal always takes the easiest path, the right strand will be chosen automatically.

AN ALTERNATIVE METHOD

You do not have to use separate cables to each driver, but may connect two or more cables in parallel if you think they have good qualities in different parts of the frequency spectrum and therefore may supplement each other. By that, it is not certain that you always can make such summing. If you think that it is possible to add a capacitor (that conducts at high frequencies) and a coil (that conducts at low frequencies) and get a circuit that conducts at all frequencies, you will be surprised when nothing gets through (!) at a frequency where each conducted decently before the connection. Cables, however, are less reactive and may therefore be summed without greater trouble.

THE DISADVANTAGE WITH BI-WIRE

One thing that happens when you biwire your loudspeakers is that the input of the high- and the low-pass filters are fed with different input signals. The difference is a result of the high frequencies and the low frequencies being forced to travel different paths, perhaps through different types of cables, but under all circumstances through cables who have seen different loads (a tweeter with a high pass filter has a completely different impedance response compared to a woofer with a low pass filter!).

What happens is that the drivers will work less good together than when their filter halves were fed with equal signals. The result is a generation of more static and stochastic phase error sounds at different directions from the loudspeaker. The stochastic phase error sounds appear because there may be different types of unlinearities in the low- and high-frequency paths.

What does this sound like? Well, usually, just as you may expect from physics, it appears as a change in the reproduction of space and sound stage. Often, the first impression is that the "biwired" sound presents extended "dimensions", more "air", and is more "living". The impression after a week or month, however, is that all recordings sound very much alike, and the "airiness" appears on all records. It does not even sound like air anymore, instead more like a slime that pollutes every record you play. No wonder, since it is not a real, recorded quality but a "speaker characteristic" added to all reproduced material. "Sameness" is another word for it.

This information is nice to know and all (I don't mean to sound like a snot here), but what about the power distribution? My original question.

Your questions have already been answered above. I posted the info just an FYI - so you would have more info before you jump in.
After all, at the end of the day, it's you who would decide if it works for you. Power distribution was not in your original question. It should matter I guess if you are going to bi-amp (using separate amps). Perhaps other members could provide info on this but I prefer (long ago) to leave my speakers alone.

Maybe something is wrong with me, but I did not see where my question was answered. My question was if I went to a biamp solution, if the power going to the speaker was doubled. I have a set of mains that can take a much larger amount of power than the center of surrounds will. 300W for the mains, 175W for the center, and 125 for the surrounds.

Now, I was thinking of getting a 7 channel amp and use two channels to go to each main. My question is if the mains would be getting twice the power as the other speakers. I would think so as there are two separately amplified lines coming in, but I want to make sure of this.

If this is true, I could look into something like the 7100, which would most likely output around 150W into 4 ohms and give me 300W to the mains and 150 to the center and surrounds. That way I would have only one amp, plenty of power for the mains and not have to worry about overloading the other speakers. Does this seem like it will work?

Sorry to stray before actually helping. My bad.

Bi-Wiring is generally defined as feeding a full range signal to an amp, going to the speaker with two pair of wires and discretely connecting the wires to distinct sections of the crossovers. This makes me laugh. Most of the theories around this one stem from folks envisioning the current surging down the wires. In fact at the frequencies and distances involved all points on any of the connected conductors see essentially the same voltage.

Bi-Amping (what you seem to want) generally refers to feeding a full range signal to a pair of amps and wiring each amp such that it drives a section of the crossover. This would isolate the two driver sections, but the amps are still driven full range. So although the current draw per amp would be reduced the onset of voltage clipping would be altered only a little in most cases. One advantage is that clipping in the bass amp would not blast harmonics into the tweeter.

The one that gives best results but is hardest to get right is Bi-Amping with active crossovers, where the amps are not driven full range. There can be benefits here, but the sonic characteristics of the speaker can also be easily compromised if done badly. This one works best inside powered speakers or if the manufacturer has specific provisions for it.

I'd just get a bigger amp.

Yes- no real change in "power rating".

I think you may be confusing bi-amping with "bridging" an amp here, Benjamin. I would not believe the new 7100 would come with this capability (bridging) and allow you to "double the power" to your speakers. So, the answer would be- no. Hope this helps!

The 7100 will not support bridging (assuming that it follows the same design approach as the 750, 770, and 755 did; the full feature list isn't out yet), but you can still use two of its channels to bi-wire a speaker (thus taking a 7x100W amp and creating a 2x200W and a 3x100W, which I think is what Benjamin is considering). From what I've been able to find (and as charlie said in his last post), you would get more power to the bi-amped speakers than you would if you bi-wired or "mono-wired," but bi-amping may be in some ways more hassle than simply going with a bigger amp (like the 755). In addition to charlie's last post, there's some more info at SMR and at soundstage.com that might be of use.

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gonk -- Saloon Links | Pre/Pro Comparison Chart | 950 Review

[This message has been edited by gonk (edited September 10, 2002).]

Bridging would be nice. Also this obsession with odd numbers of channels should go away.

Charlie

I have to disagree. If you biamp your speakers with either 2-100 watt per channel stereo amplifiers or with 4 channels of the 7 channel amp, you are still only providing a maximum of 100 watts to each side of the crossover. Each side will only see 100 watts max(assuming no dynamic headroom, etc.) and would not be doubled. To get 200 watts, IMO, you would have to bridge channels.