Puzzling experiment with Bi-wiring/Horizontal Bi-amp

Electrically speaking, unless you have been using speaker wires which are inadequate to the task, biwiring your speakers could have made no difference whatsoever. The AVR can't distinguish the two situations. If rerunning room EQ changed the response curves, then it is more likely that there were differences in the environment external to your A/V system while the calibration was in progress (background noises, rearranged furniture, different mic placement, etc).

Emotionally speaking, knowing that you've made a change will make a system seem to sound different. You'll notice things that you simply weren't paying any attention to before. They can be good or bad depending on how you feel about what you've done. A/V systems are entertainment systems. If what you've done makes you feel better, then it's done its job.

Given that you had reasonable speaker cables to sdtart with (i.e., not 24 gauge) there is no possible significant technical advantage to bi-wiring. That leaves some of us to speculate as to why you heard an "improvement". It is hard to escape thoughts about the placebo effect.

One obvious tip-off is that an improvement was reported, as it always is. If one looks at audiophile tweaks objectively, there are three possible outcomes - no change, improvement, or loss of sound quality. That improvements are *always* reported suggests that the reports are less than objective.


Not a chance. Any possible distortion in the passive crossover is unaffected by whether its input terminals are tied together with a short jumper or a couple of pieces of wire going back to the same amplifier. Most of the components in a passive crossover are inherently linear, and the ones that could possibly cause problems (e.g. iron core choke) work the same whether they are powered by a common speaker cable or two.
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Actually, little or no difference. Each amp continues to amplify the same signal and thus creates the same distortion, which is inaudible anyway, if the amps are of reasonable quality or better.



Electronic crossovers provide most of their advantages when they are an intimate part of a loudspeaker's design. They provide the speaker system designer with cost and performance advantages if that potential is exploited.

It is interesting to notice that self-powered speaker systems with electronic crossovers have very low market penetration for home audio. Some well-known, technically sophisticated and very successful speaker system manufacturers such as Paradigm have brought good self-powered speaker systems to market for years, and then dropped them. Others such as JBL offer these kinds of systems in the professional market, but not so much for home audio.

Obviously, very good sounding speakers continue to be made without electronic crossovers. There must not be that much of an inherent advantage when everything is considered.


Fact of the matter there are tons of reports of mixed results from biwiring, together with credible technical explanations of why it can't provide a signficiant advantage. But here we are!



Consider that you may be underestimating the power of expectation bias. For example placebos *cure* up to 35% of a wide spectrum of bodily ailments. Some FDA approved medications sometimes have only 50% effectiveness. Biologically impossible treatments such as homeopathy have millions of true believers.



Why would you do something that requres work-arounds to work at all?

Perhaps. And, perhaps not.



That's the crux.

j

I agree with Selden and Arny - it's highly unlikely that you've actually changed or improved anything (and without measurements/reference points for before and after, you can't say otherwise). What is more likely is that you've convinced yourself of a change, or expected a change, as a result of having changed something:
http://en.wikipedia.org/wiki/Expectation_bias

Just because you know it exists doesn't mean it doesn't affect you.

If the AVR changed its calibration settings, that will have an impact, but I'd be more curious as to what you changed in the room (do not say "nothing") that altered how the AVR "saw" the world around it.

no.
Based on your theory, lower cable channels would 'swamp' out th eupper channels. This is not the case, physics disagrees with you.


But they're connected together at the amp...no difference.


lol

Where did you find it? Was it by someone named Harley by any chance?

Regardless, SAM64 is right.

This thread was had out a while ago:
http://www.avsforum.com/avs-vb/showthread.php?t=1403074

Basically, there's no material advantage here, and all of the poetic claims to the contrary are superfluous at best unless some hard data can ever be provided by the "believers" who insist it "improves bass clarity, opens up the soundstage, and reduces distortion" - using "science words" does not defend that.

I saw a similar theory and I agree there is some effect on paper due to the current flow differences in the woofer and tweeter circuits. But it's probably immeasurable with practical test equipment and certainly not audible IMO.

Did throwing a file folder out of WTC#1 delay it's collapse? Yes it did and we can prove it with mathematics. Now how many fractions of pico seconds do you want to consider?

Same thing with a lot of the audiophile theories.

Actually, superposition is the "physics" theory which shows your quoted explanation is inaccurate. Your quoted text has lots of buzz words, but no viable mechanism.

So, nah..that explanation has no accuracy.

j

One signal can't overwhelm another signal in a linear system. In a linear system, the laws of superposition and scaling must be true. If they are true, then signals that pass through the system can't overwhelm or even affect each other.

OTOH, if a system is nonlinear, then signals that pass through it can indeed overwhelm each other as you suggest.

Biwiring does not affect either the amplifier or the speaker. The amplifier sends out the same signal regardless, and the speaker receives the same signal regarless. If biwiring affects anything relevant, then it must affect the speaker cable itself, because the speaker cable is the only thing that sees a different situation in biwiring.

In biwiring the current through the speaker cables is again the only thing that changes when biwiring is set up. The speaker cables see the same voltages since one end of each cable is attached to the same amplifier channel. However, due to the difference between the tweeter as a load and the woofer as a load, each of the biwired cables does pass different currents once biwiring is set up.

So, the question is whether or not speaker cable is linear or nonlinear.


Incorrect. In biwiring the woofer and the tweeter are still hooked in parallel, its just that the wire connecting them is quite a bit longer. If the speaker wire has a lot of resistance or a high impedance, what you describe could happen. However, even mediocre speaker wire has too low of resistance for what you describe to take place.


You have returned the discussion to the issue as to whether speaker cable is linear or nonlinear. If speaker cable is nonlinear, then the corruption or as you previously described it: "overwhelming" could take place. If speaker cable is essentially linear, then as previously show neither corruption nor overwhelming can possibly take place.


The relevance of a theory should be possible to establish in a laboratory. There should be some measurement or set of measurements that would shed light on the theory of biwiring. If the theory of biwiring predicts certain measurable occurrences, then we should be able to make measurements in a laboratory and determine whether or not they follow the predictions of any theory of biwiring.

The theory of biwiring predicts a number of things that we can test for in a laboratory context.

For example, biwiring predicts a change in the measured performance of a loudspeaker. It predicts less what you called corruption or overwhelming or as I pointed out would nonlinear distortion.

Let's cut to the chase. If biwiring has any benefits it would be due to the fact that speaker cable is somewhat nonlinear. If biwiring has any benefits, biwiring a speaker should reduce nonlinear distortion, particularly when the test signal is composed of a tone that is reproduced by the woofer and another tone that is reproduced by the tweeter.

I can tell you for sure from lab tests that I have done that biwiring does not make a significant improvement in the nonlinear distortion produced by a speaker. I can tell you for sure that speaker wire is highly linear.

Therefore, the claimed benefits of biwiring are not confirmed by laboratory tests. I invite anybody who has the necessary test equipment to duplicate and confirm or dispute my test results.

Incorrect.


Correct.


Incorrect.

I would explain it to you, but it would involve math.

You have created a strawman argument. Then shot it down.

j

I count that as an unsupported claim.

When someone says so much and makes so little sense, it's hard to keep track of the arguments; hence friendly fire always takes a toll. It's always entertaining to see someone shoot themself in the foot over and over though ; good fun for all.

OF COURSE IT'S AN UNSUPPORTED CLAIM, SILLY.

It's a friendly humerous jibe at you for that crazy comment you made on the other thread about digital reconstruction math, where you said audio is not about math...


I'm not sure who your players are..but this should indeed be fun..if I've provided humor in any fashion (especially via self deprecation), so much the better..

j