Why Bi-wiring Makes No Sense.

[johnb554]

I've figured it out. So, "it will spray further" means, in reference to audio, that the sound coming out of the speaker (end of the hose) will be louder compared to a speaker cable that is bigger and not so full of pressure.

I get it, so if I want louder speakers without having to run the risk of clipping my amplifier I should buy thinner cable which will create pressure and 'shoot' the sound out of the end resulting in an increase in db.

we should try and sell this concept to the snake oilers themselves. Maybe we should go directly to Robert Harley...who's with me???

Well.. if thats true then im going to canadian tire to buy myself a pressure washer. maybe if i first hook up the amp to the washer then hook the pressurised end up to my speakers it would be louder.

Think of all the possibilities....


Friggin BS.


p.s. i fell out of my chair laughing after i read that,

 

[Seth=L]

Well.. if thats true then im going to canadian tire to buy myself a pressure washer. maybe if i first hook up the amp to the washer then hook the pressurised end up to my speakers it would be louder.

Think of all the possibilities....


Friggin BS.


p.s. i fell out of my chair laughing after i read that,

He was joking, I hope you realize.

I really think the audiofreakazoidphiles would buy it though.

 

[johnb554]

He was joking, I hope you realize.

I really think the audiofreakazoidphiles would buy it though.

Yes, yes i think i cought up on that. I was joking too....


John

 

[johnb554]

He was joking, I hope you realize.

I really think the audiofreakazoidphiles would buy it though.

P.S. Audiofreakazoidphilesl....HAHA love the new term..


John

 

[Omicron]

The argument you put forth was that of one load, one wire. As such, your analysis is spot on. However, as you can see, it doesn't address the difference entity, the 2AB.

Hello John,

I seem to remember a very similar thread in diyaudio some time ago. I'm a bit surprised you're still struggling with the 2AB phenomenon.

The crux of the argument is (as I remember from diyaudio) that a 2AB power dissipation difference arises when comparing the 2 wire and the 1 wire cases. Problem is you're comparing apples with oranges.

Consider this: an amplifier connected with 2 wires, current A flowing in one and current B flowing in the other. I now want to compare this to the one wire case. So what do I do? I remove one of the wires and switch to the single wire situation. To be sure that the expected A+B current now flows trough the remaining wire I measure it. Lo and behold...it's not A+B but slightly LESS. What the heck?

Well, one wire obviously has more resistance than 2 wires, so that explains what I'm measuring. To continue the experiment I turn up the volume of my amp a little to compensate until I measure A+B flowing trough the one wire. I now have the situation you proposed.

Good, I now measure the power dissipated in my one wire and lo and behold...it is as you say! Up pops the mysterious 2AB.

So, where did that extra power come from? Oh..right..I DID have to turn up the volume knob to make the currents match. I'll leave it as an exercise to the reader to prove that the extra power the amplifier is putting out EXACTLY matches the 2AB term.

The conclusion is: in the bi-wire case less power is lost in the wires and the amp has to work a little less as compared to the one wire case. Simple as that. The shape of the power graph is irrelevant. The power dissipated in the speakers is exactly the same in both cases. The power delivered by the amp is NOT!

Regards,
Kurt

 

[jneutron]

Hello John,

I seem to remember a very similar thread in diyaudio some time ago. I'm a bit surprised you're still struggling with the 2AB phenomenon.

Still struggling The last post in this thread's a year old..

The crux of the argument is (as I remember from diyaudio) that a 2AB power dissipation difference arises when comparing the 2 wire and the 1 wire cases. Problem is you're comparing apples with oranges.

Nah. the crux of the argument is that for two wires, if the tweeter has one amp positive flowing at some instant, and the woof has one amp negative flowing at that same instant, a monowire has net zero current flowing with net zero wire dissipation, but biwiring has two one amp currents flowing in wires with non-zero dissipation in both.

A significant difference.

Good, I now measure the power dissipated in my one wire and lo and behold...it is as you say! Up pops the mysterious 2AB.

actually, it was there all the time. Turning the amp up or down doesn't change it relatively, just in magnitude...remember, a linear system..

The conclusion is: in the bi-wire case less power is lost in the wires and the amp has to work a little less as compared to the one wire case.

Your conclusion is not supported by your descriptors. You have not compared instantaneous power dissipation between the two scenarios.

Simple as that. The shape of the power graph is irrelevant.

Actually, the shape of the power graph is the crux of the issue. Since the wires dissipate differently in time instant, the amp and the speakers see something different.

RMS, of course, is identical between the two.

Cheers, John

 

[Omicron]

Still struggling The last post in Actually, the shape of the power graph is the crux of the issue. Since the wires dissipate differently in time instant, the amp and the speakers see something different.

RMS, of course, is identical between the two.

Cheers, John

The shape of the power graphs tells you nothing about the distortion of the sound. It was my understanding from the diyaudio thread that you were using this graph to suggest that the single wire case introduces distortion. It does not. The 2AB term is extra power delivered by the amp, the power in the speakers did not change in any shape form or magnitude between the 2 cases (simply because the same currents flow trough the speakers in either case). Hence no distortion was added. The only thing that is not the same in both cases is the power dissipated in the wires and the power delivered by the amp.

I 'm not sure what point you are trying to make with the -1 and 1 amp in the tweeter and woofer. In the case of the bi-wire the wires carry current exchanged between the 2 filters, is that what you are trying to say? In the one wire case these currents would be limited to the inside connections of the speaker. That's obviously a difference, but I fail to see how that can be seen as an advantage for the bi-wire case.

Anyway, this will be my last post on this topic as I inadvertently awakened a dead thread. If you really think you are on to something that the rest of the EE community has missed then I would suggest you create an experiment that demonstrates your theory. It should be feasible to emulate the wires, speakers etc with a few discrete components and perform some simple measurements. You can tweak the values to exacerbate the case you want to investigate. It should be trivial to demonstrate any distortion mechanism that would involve a term as significant as 2AB.

 

[jneutron]

The shape of the power graphs tells you nothing about the distortion of the sound. It was my understanding from the diyaudio thread that you were using this graph to suggest that the single wire case introduces distortion. It does not. The 2AB term is extra power delivered by the amp, the power in the speakers did not change in any shape form or magnitude between the 2 cases (simply because the same currents flow trough the speakers in either case). Hence no distortion was added. The only thing that is not the same in both cases is the power dissipated in the wires and the power delivered by the amp.

Actually, the RMS power is not different. Just the instantaneous.

But think about what you have said.. You stated ""that the 2AB is extra power delivered by the amp".. And, "The only thing that is not the same in both cases is the power dissipated in the wires and the power delivered by the amp"".

Key wording of yours...""not the same"".

Not the same is.....Different. The 2AB component is very different.

I 'm not sure what point you are trying to make with the -1 and 1 amp in the tweeter and woofer.

That's easy. It is a point in time where a monowire has NO current flowing within it, but the biwires do. Hence, the monowire dissipates no power, the biwires do.

So, at this time, you goose the biwire amp to compensate??? Works great for that instant, but what happens when both currents are same direction? Monowire has twice the dissipation...so now you turn the biwire amp down???

As I said, the dissipation profiles are different.

Anyway, this will be my last post on this topic as I inadvertently awakened a dead thread.

It is only as dead as one wishes. You wished to talk, here I am.

If you really think you are on to something that the rest of the EE community has missed then I would suggest you create an experiment that demonstrates your theory. It should be feasible to emulate the wires, speakers etc with a few discrete components and perform some simple measurements. You can tweak the values to exacerbate the case you want to investigate. It should be trivial to demonstrate any distortion mechanism that would involve a term as significant as 2AB.

The question is, what instrument to use for measurement of the distortion. The 2AB component is a zero integral power waveform. FFT's are not the best choice. I posted test schematics somewhere, if you're interested.

Cheers, John

 

[stratman]

I'm just waiting to see who's going to pull the lightsaber first. You know fellas there's this editorial by Mr. Andry....................The Jedi Church.

 

[no. 5]

I'm just waiting to see who's going to pull the lightsaber first. You know fellas there's this editorial by Mr. Andry....................The Jedi Church.

"Clearly this battle cannot be won with our knowledge of the electron, but through our skills with the lightsaber."

 

[haraldo]

Thanks Seth=L

Re: Post#1 in this thread
The greatest laugh I've had for a long time, and I have heard many good jokes lately

 

[Omicron]

Actually, the RMS power is not different. Just the instantaneous.

I'm assuming you mean average power instead of RMS power (there is no such thing). I'm not sure what power you are referring to. I was talking about the bi-wire versus the one wire experiment I described in my first post. In this the power in the speakers was the same (both average and instantaneous) in both cases. If the current trough the speakers didn't change then neither did the power put out by them. And hence there was no mechanism for distortion.

As I said, the dissipation profiles are different.

Sure, there is a difference in the power lost in the wires. No argument there. But it is the power put out by the speakers that interests us, not the power that was lost in other parts of the system. If you can show that the power curve of the speakers changed shape THEN you would be on to something. Alas, it didn't.

It is only as dead as one wishes. You wished to talk, here I am.

Yes, but are you willing to listen? You seem too deeply entrenched in your misconceptions for anyone to get through.

The question is, what instrument to use for measurement of the distortion. The 2AB component is a zero integral power waveform. FFT's are not the best choice.

A component as big as 2AB will be quite apparent even in the time domain. The 2AB component will be of the same size as the the original waveforms if you select both amplitudes to be 1. Any distortion in that order of magnitude will scream out at you on any garden variety oscilloscope.

But really the point is that distortion is measured not on the power waveform (which is irrelevant, but I resign to the fact that you are not going to accept this) but on the voltage (or current) waveforms as those are the analogue for the sound pressure produced by the speakers.

Another point I would like to make is that you have to be very careful about making simplifications in the way you've made them. For example as far as I know no real linear system could ever split the lf and the hf so that both would be pure sine waves as this would assume an infinitely steep filter. I have a sneaking feeling that this simplified circuit no longer is a linear circuit at all and it may lead to some paradoxical situations if you try to do the math on it.

Oh well, I guess I couldn't resist replying once more after all

 

[stratman]

"Clearly this battle cannot be won with our knowledge of the electron, but through our skills with the lightsaber."

Dark Helmet my electron is bigger than yours. May the scwartz be with you, Yogurt.

 

[jneutron]

I'm assuming you mean average power instead of RMS power (there is no such thing).

Semantics..yes, I do indeed time integrated power....

I'm not sure what power you are referring to. I was talking about the bi-wire versus the one wire experiment I described in my first post. In this the power in the speakers was the same (both average and instantaneous) in both cases. If the current trough the speakers didn't change then neither did the power put out by them. And hence there was no mechanism for distortion.

Experiment? You meant thought experiment, correct?

Sure, there is a difference in the power lost in the wires. No argument there.

Excellent..a start.

Now, connect both a biwire set AND a monowire set to the exact same amplifier terminals.. what you will "see" is that the dissipation differs, so the power that is received by the speaker sets will indeed be different. And, not by a simple gain factor..so dropping the wire guage to compensate...doesn't do it correctly.

But it is the power put out by the speakers that interests us, not the power that was lost in other parts of the system. If you can show that the power curve of the speakers changed shape THEN you would be on to something.

Hence, the reason to explain it to you..the powerloss in the monowire has three components to it. A squared and B squared are identical in both cases..but in monowire, the third part is the diff..

Yes, but are you willing to listen? You seem too deeply entrenched in your misconceptions for anyone to get through.

You've pointed out no misconceptions...diversion by stating I am unwilling to listen has just been called out as such..please refrain from such tactics in the future, and discuss the issue.

A component as big as 2AB will be quite apparent even in the time domain. The 2AB component will be of the same size as the the original waveforms if you select both amplitudes to be 1. Any distortion in that order of magnitude will scream out at you on any garden variety oscilloscope.

Alas, what you look for is what you see. You can't look across the wire for it, you'll see what is expected based on the current within... Look where it counts..

Another point I would like to make is that you have to be very careful about making simplifications in the way you've made them. For example as far as I know no real linear system could ever split the lf and the hf so that both would be pure sine waves as this would assume an infinitely steep filter. I have a sneaking feeling that this simplified circuit no longer is a linear circuit at all and it may lead to some paradoxical situations if you try to do the math on it.

You would be incorrect on all counts there..first order, with breakpoints far removed.

Oh well, I guess I couldn't resist replying once more after all

That is good. One can hope that you still cannot resist, and discuss.

Discussion is good.

Cheers, John

 

[Sheep]

I'm waiting for the "is it audible" arguement. That one is the only one that pertains to me, the human.

SheepStar

 

[haraldo]

I'm waiting for the "is it audible" arguement. That one is the only one that pertains to me, the human.

SheepStar

The argument is that there is this magical yet to be proven ultramegaproton force that makes the quarks align in such a way that the electrons synchronize the rotation frequency so that the resistance complies with the unknown great unified force that noone has ever proven to be there and that makes so much a difference that anyone will hear it.

 

[Seth=L]

I'm waiting for the "is it audible" arguement. That one is the only one that pertains to me, the human.

SheepStar

You won't see a credible one.

 

[Omicron]

You've pointed out no misconceptions.

Ok, maybe I should be more explicit then.

In your arguments you always assume that the amplifier puts out a nice "clean" power waveform (no 2AB present in it). You then reason that the power in the speakers must be the difference between that nice clean power shape and the weirdness of the power lost in the wires. At the same time however, the thought experiment also makes sure that the currents through the speakers remain the same. I am referring to the thought experiment in my first post here (let's not complicate things by attaching both cases to the amplifier at the same time). In both cases A flows through the tweeter and B flows through the woofer.

Now, don't you see that this is a contradiction? The power in the speakers can only change if the currents through them changed. Yet the thought experiment was arranged such that those where kept constant!

The only interpretation that makes sense is that the power in the speakers remained exactly the same but that the power put out by the amplifier changed. Yes, the 2AB term is coming 100% from the amplifier.

You seem to have trouble believing this because I only "turned up the volume" a bit. And yet the result was not a simple "scaling" of the power output. No, instead the shape changed! Well, that kind of weirdness is inherent in the beast. Power is not a linear function. And the volume was off course not the only thing that changed, the amplifier is seeing 2 different circuits from its perspective with 2 different impedances. There is nothing mysterious going on anywhere in this.

You would be incorrect on all counts there..first order, with breakpoints far removed.

A first order filter (or any order filter for that matter) can never reduce a signal to zero. It can attenuate it, sure. But it cannot make it disappear.

 

[Seth=L]

I believe this debate, while fairly civil, is almost pointless. I don't speak for everyone here, but I don't think most of have any clue what you are talking about.

 

[Omicron]

I believe this debate, while fairly civil, is almost pointless. I don't speak for everyone here, but I don't think most of have any clue what you are talking about.

Well, I certainly apologize for any pollution of the forum I might have caused by inadvertently re-opening this thread. I admit I didn't check the dates when I posted my original message.

Although I can imagine the argument might seem high tech, it really isn't. This is first year EE stuff.