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Why bi-wiring is bad

From a link at the Chris Van-Haus website:
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.

I just went back to bi-wiring over the weekend. The first thing I noticed was cymbal-like instruments shimmer much more. Secondly the bass now seemed to be less perhaps due to the greater high frequency information.
On orchestra music the orchestra is now well behind the speakers instead of right at the speaker. Like the article said, this may be a phase or time shift error and the depth may become wearing over time.
Finally there is slighlty better separation between instruments. It's easier to pick out each instrument.
cdc
prd
13 posts
 
Although I am far from an expert, I have found Jon Risch's explanation and arguments in favor of biwiring convincing. I, too, had trouble understanding how two different cables that were connected at the same (amp) end could possibly be carrying two different signals. Risch provides a very detailed explanation of how biwiring works and although I cannot confirm the technical aspects it is certainly consistent with everything I have read about speaker crossover design. If you are at all curious the article is well worth the read.

That being said, there is much truth to the statement that one high-quality cable will better a lower-quality biwired cable.

http://www.geocities.com/jonrisch/biwiring.htm

- Paul
karls
332 posts
 
I just went and looked at the Jon Risch link above, and while he has some good points, it is very oversimplified and doesn't acknowledge any of the limitations of biwiring, namely:

(1) the obvious potential for intentional and unintentional response "tweaking" that will occur using two cables rather than one, and especially two different cables (which seems to be what he is suggesting, although he doesn't come right out and say it). This can be either better or worse than the performance you would get from a single wire, depending more on random chance than anything else given the complexity of most crossovers. I'm not against tweaking the sound with cables; I just think that you ought to be honest about what you are doing.

(2) Even more important, the fact that biwiring will automatically and by default restrict the crossover design itself to a true parallel type. This in itself and all by itself is way more than enough reason to give up biwiring, in order to have the flexibility in crossover design to pursue series alignments or any number of more complex schemes.

There are a lot of pseudo-"experts" out there, and quite often I find that I am honestly not satisfied with their answers to complex technical problems; they seem to latch onto an "answer" without having adequate technical proof of the superiority of this answer. Biwiring is not necessarily a bad thing, and it is not necessarily a good thing. It is going to depend on the exact speaker drivers and cabinet design, the exact crossover topology and parts, the exact wire used, and even the amplifier(s)' own characteristics. This is one giant ball of issues all rolled into one, and any one of them is going to have a tremendous effect on the end result, but of all of them, the wire is probably going to affect it the least. That is why I refer back to #2 above; far better to be able to optimize the crossover properly than to be stuck in a "parallel" universe forever.
basement
245 posts
 
Just from a logic standpoint, this doesn't appear to make sence to me. It sounds right off that what is being stated is that the different drivers receive signals that are not identical, because of the different laods of the drivers.
Since one driver is not getting a signal affected by the load of another driver.
The last time I checked, this was the reason for biwiring.
If I understand this correctly, he is claiming that this is wrong because the signal does not have the same load? The speakers have different laods, feeding them a signal which is effected by all loads of all drivers will not change this.
If, as he infers, the signal is the same because the load is shared, the drivers would as a rule react differently because they have different loads. The signal would actaully be different to the different drivers, not the same, by the very nature of his claim.
Last but not least, his claim of less static and stochastic phase error caused by single wiring, and/or containing all loads in the same signal is unfounded in this statement. And therefore, his assesments.
And I see myself as not knowing too much about this subject. I just see his statement, reasons, and conclusion as contradicting within itself.
It could be that he left out some information, mistated, or that I don't know enough to be able to understand correctly, or it is supposed to be understtod that the reader of such have a certain level of knowledge on the subject.
Post removed 
zaikesman
3,017 posts
 
I have never been able to bring myself to believe the commonly-heard explanation that biwiring somehow reduces or eliminates an alleged modulation of the mid/treble frequencies supposedly caused by the back-EMF of the woofer. In fact, the whole "back-EMF modulation" concept has a stink of implausability about it to me, but I'm not expert enough (actually, at all) to really know why I suspect this. There's just a 'lift yourself up by your own bootstraps' air about the concept.

Besides, it doesn't seem as if the amplifier is 'seeing' anything different in biwiring, other than the extra set of cables. I tend to believe it is simply just the presence of this additional wire that results in any sonic change. But then again, I'm a Thiel owner, so what the hell do I know? (Saves on cable costs, tho'...)
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