Why Bi-wiring Makes No Sense.

[jneutron]

The derivation I presented in post 369 doesn't assume anything about the powers, hence there is no circular logic. It calculates all the powers based on the currents and the voltages.

Duh.

And the assumptions you used to derive the filter power is based on the assumption of the load voltage and the load current..which is based on the filter dissipation..which is based on the wireloss..which is based on the supplied current..which is premised on the system impedance..which is based on the load voltage...circular, circular, circular..

Again, duh.

Circular logic.

As I said, there is nothing shameful in not being able to attack the problem from another direction.

Try writing a simple recursive integration program...break time down to the nanosecond, write the formulas for energy transfer, cap and inductor storage...heck, once you've laid the groundwork, you can even put in the heat capacity of the wires to see exactly what the isothermal wire temperature is vs time. Even tie in the dielectric parameters.

It's not too hard to do. Try it..and welcome to my world..

My equations are out there for all to see. That's more than we will ever get from you.

Your equations??...you don't understand them well, do you.

Don't you know, the apparent power dissipation in the caps and inductor is a function of time and totel enclosed energy? You have to take the stored energy deriviative to calculate the apparent power..you know...the deriviative of either 1/2 LI squared or 1/2 CV squared..

Do you really think they are exactly 20 watts??

You crack me up...Between this thread, the one at diy, the one at props, the one at AH, the equations are all there for the world to see.

Do a search...it's there, regardless of what you say.

Have a happy life John. Whatever you've been smoking lately, it must be good!

My goodness..without actually being able to derive the differentials, you have only left the childish remarks?

Your abilities are certainly there for all to see.

Cheers, John

ps...Instead of acting so stupidly in your feeble attemps at trying to undermine my analysis..you should have asked the one person who is most qualified to question my analysis. The one person who would have told you the strengths, the weaknesses..the possible logic flaws..

Me. I have no problem discussing the possible flaws of my analysis. Unfortunately, you were too busy acting like an idiot.. I didn't think that of you previously.. But your present behaviour..has changed my opinion of you.

Toodles.

John

 

[Omicron]

And the assumptions you used to derive the filter power is based on the assumption of the load voltage and the load current..which is based on the filter dissipation..

Nope. The load current and voltage were based on the impedance of the filter.

 

[jneutron]

Nope. The load current and voltage were based on the impedance of the filter.

Really now..at what frequency..and at what energy level within the elements.

Trust me, your analysis certainly doesn't cover that...

Hand waving is of no use.

TTFN, John

 

[Omicron]

Really now..at what frequency..and at what energy level within the elements.

Trust me, your analysis certainly doesn't cover that...

Hand waving is of no use.

TTFN, John

Ideal filters remember. Infinite impedance for signal Ia and zero impedance for signal Ib. And vice versa for the other filter.

 

[jneutron]

Ideal filters remember. Infinite impedance for signal Ia and zero impedance for signal Ib. And vice versa for the other filter.

You haven't answered the question.

How do you derive the dE/dt of the filters to arrive at the effective power dissipation figure for the filters. Remember, the number is dynamic..

Hmmm?

Look, it's NOT a difficult question..if you don't know the answer, just say so..

Cheers, John

ps.. Sheesh, and this is one of the easier parts of the analysis..what ya gonna do when I ask ya the difficult ones???

 

[Omicron]

How do you derive the dE/dt of the filters to arrive at the effective power dissipation figure for the filters.

Look at post 369 and see how easy it is to derive the power terms for the filters.

At any instant in time:

dE/dt = p(t) = v(t) * i(t)

Simple as that. The derivation in post 369 uses this basic fact.

 

[jneutron]

Why in gods name would I need to do that? Look at post 369 and see how easy it is to derive the power terms for the filters.

At any instant in time:

p(t) = v(t) * i(t)

Very good...you passed that one..took a while..but ya got it.. (well, I think you understand...anybody can google p = vi...so I'm still wondering...

You do understand the difference between instantaneous values and RMS, peak or average values do you? I get the distinct impression you don't.

Oh duh, diversion and obfuscation...not becoming of ya...

Now, slide the wiring node from the speakers to the amp, and detail exactly how the system response changes..

Then, detail a schematic which will produce the exact impact that change will have on both the voltage and phase response at both the drivers for each band.

I have..can you?

Cheers, John

 

[Omicron]

I have..can you?

Well, what's the problem then? Why are you so unwilling to show it to me?

 

[Omicron]

Now, slide the wiring node from the speakers to the amp, and detail exactly how the system response changes..

Supposing you mean this:

- a wire from amp to the node
- one wire from the node to each filter

Then move that node closer to the amp. Correct?

Well, the equations in post 369 hold for that case if you replace:

Rtweeter with Rtweeter + Rwire-tweeter-filter
Rwoofer with Rwoofer + Rwire-woofer-filter

Sliding the node then just means decreasing Rwire and increasing Rwire-tweeter-filter and Rwire-woofer-filter.

The shape of p(t) of the speakers doesn't change since the equations didn't fundamentally change. Although the magnitude of p(t) may change. Hence at most just a linear scaling of voltage and current in the speakers, no distortion.

So, there you have my analysis. Didn't take me long did it?

 

[jneutron]

Supposing you mean this:

- a wire from amp to the node
- one wire from the node to each filter

Then move that node closer to the amp. Correct?

Well, the equations in post 369 hold for that case if you replace:

Rtweeter with Rtweeter + Rwire-tweeter-filter
Rwoofer with Rwoofer + Rwire-woofer-filter

Sliding the node then just means decreasing Rwire and increasing Rwire-tweeter-filter and Rwire-woofer-filter.

The shape of p(t) of the speakers doesn't change since the equations didn't fundamentally change. Although the magnitude of p(t) may change. Hence at most just a linear scaling of voltage and current in the speakers, no distortion.

So, there you have my analysis. Didn't take me long did it?

The correct answer would have taken a bit longer.

Sigh..back to the previous question..

You said the effective power diss of the filters was P = VI.

For the tweeter cap, what is V and what is I..

(don't worry, we'll eventually get to the finish line)
Cheers, John

 

[jneutron]

Well, what's the problem then? Why are you so unwilling to show it to me?

It is necessary for you to come to the understanding on your own.

Giving somebody a fish is a short term solution.

I don't think short term.

You need to look up the term "emotional intelligence".

Cheers, John

 

[haraldo]

I don't think your breaking any rules here..nor I.

When you are arguing with the correct model in hand, maybe you will provide something that is credible and coherent to kill the analysis.....course, maybe ya wont..but arguing with the wrong model in mind, is just silly and non productive.

John

You two guys could actually write a book, combine forces and write about the subject... Guess it will be like 1100 Pages

 

[Omicron]

You said the effective power diss of the filters was P = VI.

I don't know what you mean by "effective power" What I said is that at any instant in time P = VI. All being functions of time.

For the tweeter cap, what is V and what is I.

Come on John, did you actually read post 369? The equations are there. *sigh* I'll repeat:

--- quote from post 369 ---
We know filter 1 has infinite impedance for current Ib, so it cannot pass it. We also know it has zero impedance for current Ia so it cannot drop any voltage due to that. Also consider that the voltage at the end of the wire is:

Vend-wire = Vb - Ib*Rwire + Va - Ia*Rwire

This voltage drops over the filter and the speaker. Since the filter cannot have a voltage component due to Ia over it it's voltage must be:

Vfilter1 = Vb - Ib*Rwire
--- end quote ---

filter1 being the tweeter filter, Ib being LF current and Ia being the HF current provided by the amp. Vb being the LF voltage at the amp terminals, Va being the HF voltage at the amp terminals. All functions of time.

All this was explained at length in post 369. Do me the courtesy to actually read it.

 

[jneutron]

I don't know what you mean by "effective power" What I said is that at any instant in time P = VI. All being functions of time.

By effective power, I mean the power you have assigned to each filter element, you know, the 20 watts..

Come on John, did you actually read post 369? The equations are there. *sigh* I'll repeat:

--- quote from post 369 ---
We know filter 1 has infinite impedance for current Ib, so it cannot pass it. We also know it has zero impedance for current Ia so it cannot drop any voltage due to that. Also consider that the voltage at the end of the wire is:

Vend-wire = Vb - Ib*Rwire + Va - Ia*Rwire

This voltage drops over the filter and the speaker. Since the filter cannot have a voltage component due to Ia over it it's voltage must be:

Vfilter1 = Vb - Ib*Rwire
--- end quote ---

filter1 being the tweeter filter, Ib being LF current and Ia being the HF current provided by the amp. Vb being the LF voltage at the amp terminals, Va being the HF voltage at the amp terminals. All functions of time.

All this was explained at length in post 369. Do me the courtesy to actually read it.

There is a reason I asked the question.. It was not to get you to repeat the question, it was to get the specific verbage that I wanted you to repeat.

Patience, grasshopper.. (loved that line, sorry).

Now, replace the woofer ideal resistor of the model with an element that lags it's current by 90 degrees...

Notice it alters the power of the filter by that Ib*rwire amount.

In other words, when you put a real life speaker driver into a monowire system, you alter the filter powers (your equations) by the OUT OF PHASE component, the back EMF plus the coil inductance.

But guess what? For biwiring, that out of phase woofer current has been decoupled from affecting the tweeter filter.

And that alteration of filter power? That ugly 2AB rears it's ugly head, doesn't it?

Cheers, John

 

[jneutron]

You two guys could actually write a book, combine forces and write about the subject... Guess it will be like 1100 Pages

You talking about science fiction, murder mystery, or comedy?

Cheers, John

 

[Omicron]

Now, replace the woofer ideal resistor of the model with an element that lags it's current by 90 degrees...

Notice it alters the power of the filter by that Ib*rwire amount.

In other words, when you put a real life speaker driver into a monowire system, you alter the filter powers (your equations) by the OUT OF PHASE component, the back EMF plus the coil inductance.

Are you now actually claiming a "real world" speaker lags it's current 90 degrees? Care to explain to me how such a speaker can emit any sound energy at all? Average power output of a pure reactance is 0 remember...

And what in gods name makes you claim the tweeter in the bi-wire case is "isolated? in any way from the woofer? The equations for the power term of tweeter filter look like this (for the bi-wire circuit with resistive speakers, not the madness you just suggested):

Pfilter1 = Ia*Ib*(Rwoofer + Rwire2)

Rwire2 being the resistance of the woofer wires. I told you how to transform my equations for the bi-wire case didn't I? Simply replace Rwoofer with Rwoofer + Rwire2 and Rtweeter with Rtweeter + Rwire1 and set Rwire to zero.

So how on earth can you claim it is "isolated" from anything? In BOTH cases the power in the filters is the product of Ia and Ib. Only the magnitude is different.

 

[jneutron]

Are you now actually claiming a "real world" speaker lags it's current 90 degrees? Care to explain to me how such a speaker can emit any sound energy at all? Average power output of a pure reactance is 0 remember...

Oh get real. Inductance lags by 90 degrees.

Woofers are not pure resistors. Guess what? Find a reactance plot for one..

Hint: try 4th order bandpass first, then bass reflex, T-line, dipole...go ahead, we can wait..

Please don't abuse my equations by using them on a different circuit. That's just nuts. The maths for what you suggest look quite different.

Oh duh.. The math you present details the path for the interaction.

The assumption that drivers are pure resistors is the nuts part. What do you think the model is representing???

Face it, just as YOU stated, there is an interaction between the filter power and the woofer voltage minus R times the woofer current...

To now deny the interaction is silly. Where did you think I was leading you?

And what in gods name makes you claim the tweeter in the bi-wire case is "isolated? in any way from the woofer? The equations for the power term of tweeter filter look like this (for the bi-wire circuit with resistive speakers, not the madness you just suggested):

Pfilter1 = Ia*Ib*(Rwoofer + Rwire2)

Rwire2 being the resistance of the woofer wires. I told you how to transform my equations for the bi-wire case didn't I? Simply replace Rwoofer with Rwoofer + Rwire2 and Rtweeter with Rtweeter + Rwire1 and set Rwire to zero.

So how on earth can you claim it is "isolated" from anything? In BOTH cases the power in the filters is the product of Ia and Ib. Only the magnitude is different.

This is why I've been repeating questions...you still don't get it, do you?

I repeat:

For biwiring, that out of phase woofer current has been decoupled from affecting the tweeter filter

.

What part of woofer current do you not understand???

In biwiring, the woofer current is decoupled from affecting the tweeter filter. And DUH, you showed by equation, how the woofer current was related to the tweeter filter power...

It can be 100 milliamps or 100 amps. When the amplifier can support the current, the woofer current doesn't alter what the tweeter or tweeter filter sees.

YOU ARE STUCK IN A BOX... I did not say woofer voltage was decoupled.

You need to sit back, and re-read my last coupla posts...

Your trying to respond too fast, and are missing the big picture..

And after all my effort to get you to understand it on your own..

Cheers, John

 

[Omicron]

In biwiring, the woofer current is decoupled from affecting the tweeter filter. And DUH, you showed by equation, how the woofer current was related to the tweeter filter power...

Come on John! The tweeter filter power in the bi-wire case is given by the equation:

Pfilter1 = Ia * Ib * (Rwoofer + Rwoofer-wire)

It is NOT decoupled AT ALL from the woofer current.

The equations for the mono-wire and the bi-wire can be transformed into one another. I've shown you how to do that.

Clearly you don't understand high school math.

 

[jonnythan]

jneutron is arguing that Omicron's math is wrong, but.... he's the only one presenting any math at all.

 

[Omicron]

jneutron is arguing that Omicron's math is wrong, but.... he's the only one presenting any math at all.

Actually jneutron is arguing that everyone's math is wrong. Except his off course. Which he doesn't want to show because us mere mortals just need to discover it for ourselves..