Why Bi-wiring Makes No Sense.

[Bruno Putzeys]

Jneutron,

Whoa two straw man arguments and an ad hominem in one post.

Straw man 1: Where did I argue that biwiring makes no difference? Nowhere.
Straw man 2: Where did I argue that the instantaneous power dissipation in the cables is not different? Nowhere.

The point I am making is that no nonlinear effects ensue as far as the currents and voltages appearing at the speaker terminals are concerned. No intermodulation, nothing, Any differences are linear effects, which are very small.

Ad hominem: My number of posts. Please google my name and see how obscure and unknowledgeable I am about audio.

 

[jneutron]

Jneutron,

Whoa two straw man arguments and an ad hominem in one post.

Straw man 1: Where did I argue that biwiring makes no difference? Nowhere.
Straw man 2: Where did I argue that the instantaneous power dissipation in the cables is not different? Nowhere.

The point I am making is that no nonlinear effects ensue as far as the currents and voltages appearing at the speaker terminals are concerned. No intermodulation, nothing, Any differences are linear effects, which are very small.

Ad hominem: My number of posts. Please google my name and see how obscure and unknowledgeable I am about audio.

My goodness, you are incorrect..

First, strawman 1...I've not attributed any position to you. The discussion from which you pulled that comment is entirely out of context. The purpose of assuming that is to setup the conditions which are being tested. The dissipation anomoly NEEDS that condition in order to test the assumption..

Second, strawman 2. I also did not attribute you with having said the dissipation is the same. Again, please read more carefully....I have setup a specific argument, with the conditions imposed, for clarity of discussion.

I have no idea why you came back the way you did.

Focus on the problem at hand, and do not react in such a non-academic fashion..nobody is out to get you. Especially me..

Re Ad hom...Where, oh where, did you ever get the impression that I attributed the total number of posts you have at this forum with your level of understanding? Please, you should know better than to react in that fashion..

If I wish to see your name, all I have to do is check my e-mail inbox and my e-mail outbox.. (what are you thinking??)

Please post a little more professionally..one of your stature should not react as you did..

Cheers, John

ps..you obviously have had some interesting forum discussions with low level people who do not know you, or your considerable experience..and you have erroneously reacted to me as if I am in that category. I take no offense, but caution you in your error..



Now, can we get back to the discussion at hand? Thanks.

 

[FLZapped]

Cool...

The currents and the resistance are normalized, so the peak woof and tweet currents are 1, and the resistance of the wire is also normalized to 1.

The woof current is the blue line, the diss is (Asquared) I²R, so as you can see, it peaks at 1, and is always positive (real dissipation cannot be negative). It is your basic sine squared waveform, a direct result of the woof current flowing through a wire by itself. Note that for an ideal load, this is also exactly the same dissipation time profile scaled differently.

The tweet current is the magenta line, called Bsquared. again, I squared R...

With biwiring, the total wire dissipation is of course, the sum of the two, A squared plus B squared, and the load dissipation at the speakers is an exact scale of the wire dissipation.

The yellow line (asq plus b sq) is the summation of the wire loss in biwiring.

Now, consider both signals travelling in one wire, such as monowiring..

The equation is P = I²R, with I = A + B

(A+B)² = A² + B² + 2AB.

So, subbing A + B for I creates 3 parts of the power dissipation, the third and most interesting component being the 2AB part..

I put that on the graph, that is the brown (I think) color. Note two very important things about the 2AB component...

1. It goes NEGATIVE!! At first blush, that seems impossible..However, look at it's value compared to the yellow line which is the A² + B² part....note that if you sum them, they NEVER go negative. In other words, the 2AB component is a modulation of the expected dissipation. So, the monowire dissipation never goes negative..

2. It is a ZERO INTEGRAL power waveform...in other words, what is below zero is exactly the same area as that above zero. Since FFT algorithms cannot spot a zero integral power waveform, it isn't seen.


Think of the instant in time when the woof has 1 ampere positive and the tweet has one ampere negative...at that instant, a monowire sees zero current, therefore zero power loss within the wire... But, a biwire setup has one ampere in the bass wire with it's dissipation, the tweet wire has negative one ampere and the exact same loss as the bass wire...

The result? In a monowire setup, the current of one signal will modulate the losses that are caused by the other..when I see loop resistance recommendations at the 5% level, I cringe..

Cheers, John

sigh..I hate it when I can't wrap the explanation around the graphs..it's a pita when the graph goes off screen while you read the verbage..and I hate it even more when I forget what website supports what notation...

OK, I've finished editing my huge quantity of errors (I think)

Actually I think the examples on the following page more acurately represents what is going on:

http://www.kettering.edu/~drussell/Demos/superposition/superposition.html

The simple model previously presented has problems, while current appears to be going negative in one leg in bi-wiring, it really isn't because the source still represents (A+B)^2, or just I^2, and the real curent flow in both wires is zero, not +1 and -1. In this case, factorizing can yield the wrong answer because it has made the wires the source, not the amplifier.

-Bruce

 

[jneutron]

Actually I think the examples on the following page more acurately represents what is going on:

http://www.kettering.edu/~drussell/Demos/superposition/superposition.html-Bruce

Hey there Bruce..

Your link points to some really cool animations.

Unfortunately, they have no bearing in the discussion..but they are cool..

The simple model previously presented has problems, while current appears to be going negative in one leg in bi-wiring, it really isn't because the source still represents (A+B)^2, or just I^2, and the real curent flow in both wires is zero, not +1 and -1. In this case, factorizing can yield the wrong answer because it has made the wires the source, not the amplifier.

Did you just say that the current in either leg of the biwire only "appears" to be going negative? Are you sure you meant current? As it is a trivial thing to actually measure negative current in either leg of the biwire.

Methinks you meant power.

And, the power cannot go negative.. I've stated that all along..the 2AB component indeed goes negative, but it cannot exist without the two other terms, so no laws are violated.

Repeat what I told Bruno to do. Then explain to me why the power doesn't add up properly.
Cheers, John

ps...my usb mouse just died...strange..did you do that Bruce??

 

[stratman]

So post 165 has all the answers, I can't believe it took a caveman.

 

[jneutron]

So post 165 has all the answers, I can't believe it took a caveman.

I go allllllllll the way back to post # 165 to see what you are talking about, and it's your OWN POST!!!!

You're a despicable and shameless caveman.

Cheers, John

ps..wish I had a picture of daffy duck to put there..

 

[FLZapped]

Hey there Bruce..

Your link points to some really cool animations.

Unfortunately, they have no bearing in the discussion..but they are cool..


Did you just say that the current in either leg of the biwire only "appears" to be going negative? Are you sure you meant current? As it is a trivial thing to actually measure negative current in either leg of the biwire.

Methinks you meant power.

And, the power cannot go negative.. I've stated that all along..the 2AB component indeed goes negative, but it cannot exist without the two other terms, so no laws are violated.

Repeat what I told Bruno to do. Then explain to me why the power doesn't add up properly.
Cheers, John

ps...my usb mouse just died...strange..did you do that Bruce??

Your factorized formula was current only. Where you went from
I^2 = (A+B)^2 to A^2 + B^2 +2AB

And, then you also said this:

"Think of the instant in time when the woof has 1 ampere positive and the tweet has one ampere negative...at that instant, a monowire sees zero current, therefore zero power loss within the wire... But, a biwire setup has one ampere in the bass wire with it's dissipation, the tweet wire has negative one ampere and the exact same loss as the bass wire..."

And as I stated, it gives the wrong answers because in order to get an instantaneous current of +1 and -1 amp in the two legs, you'd have to have two sources.

But we don't have that, we have a single source driving both legs (the power amplifier) therefore, the current is really zero in both legs, just as it would be in the mono-wire case, because it is the amplifier that is putting out zero curent, not the speakers, or the wires, etc.

So I guess what I am saying is that you cannot in reality have the condition of +1 amp in the woof and -1 amp in the tweet when a single amplifier driving the whole thing is putting out zero amps.

Oh and yes, I did that. BWAHHAHAHAHAHAHAA.....

-Bruce

 

[Resident Loser]

What's...

...all this then?

Everybody knows wire is wire and bi-wiring is really buy-wiring cuz ya' gotsta buy twice as much...

Now everybody calm down, drop one of those multiple-mono, psuedo stereofied, bits of bombast on the old CDP and pretend that all this cr@p has any relevance to the real world whatsoever...

jimHJJ(...Hi John, wassupppp...)

 

[FLZapped]

...all this then?

Everybody knows wire is wire and bi-wiring is really buy-wiring cuz ya' gotsta buy twice as much...

Now everybody calm down, drop one of those multiple-mono, psuedo stereofied, bits of bombast on the old CDP and pretend that all this cr@p has any relevance to the real world whatsoever...

jimHJJ(...Hi John, wassupppp...)

Hey Jim, think they can tell it's slow over at AR

-Bruce

 

[stratman]

I go allllllllll the way back to post # 165 to see what you are talking about, and it's your OWN POST!!!!

You're a despicable and shameless caveman.

Cheers, John

ps..wish I had a picture of daffy duck to put there..

The Gecko is despicable, Me? Simple minded(maybe a little shameless.) Give me a Strat or a Les Paul and I'm content, oh don't forget the Marshall.

 

[Resident Loser]

I wish...

Hey Jim, think they can tell it's slow over at AR

-Bruce

...I'd seen this thread earlier...imagine two of my heroes Rod Elliot and jneutron participating (???) in the same thread...it's a pity much of it is over my head, but then again what isn't...Quite interesting reading though...I love the interweb!

jimHJJ(...it causes me to look things up...BTW, g'day Bruce...)

 

[gmichael]

Great thread, very informative even for us cave crowd. Bottom line: no need to bi-wire, use good quality "common sense" wiring, make sure you pay attention to room acoustics and speaker placement, make sure all your connections are tight.......apart form the intellectual EE arguments and pleas, to a simple mind such as mine comes the natural conclusion stated above. Common Audioholics sense wouldn't you say?

So, I don't need to split an atom to get good sound?

Hey Frank! Cancel my order will ya!?

 

[Resident Loser]

Hey, Bruce...

So, I don't need to split an atom to get good sound?

Hey Frank! Cancel my order will ya!?

...you're right...

jimHJJ(...it is slow at AR...)

 

[jneutron]

Your factorized formula was current only. Where you went from
I^2 = (A+B)^2 to A^2 + B^2 +2AB

No, that is normalized power equation

And, then you also said this:

"Think of the instant in time when the woof has 1 ampere positive and the tweet has one ampere negative...at that instant, a monowire sees zero current, therefore zero power loss within the wire... But, a biwire setup has one ampere in the bass wire with it's dissipation, the tweet wire has negative one ampere and the exact same loss as the bass wire..."

And as I stated, it gives the wrong answers because in order to get an instantaneous current of +1 and -1 amp in the two legs, you'd have to have two sources.

Nah, that's not how it works. The tweeter and woofer must at some point in time, have equal and opposite currents, as they are orthogonal currents, meaning uncorrelated.

But we don't have that, we have a single source driving both legs (the power amplifier) therefore, the current is really zero in both legs, just as it would be in the mono-wire case, because it is the amplifier that is putting out zero curent, not the speakers, or the wires, etc.
So I guess what I am saying is that you cannot in reality have the condition of +1 amp in the woof and -1 amp in the tweet when a single amplifier driving the whole thing is putting out zero amps.

You are saying that in order to get a tweet to -1 amp and a woof to +1 amp, you need two amps? That certainly doesn't explain why my two way speaker works..

Oh and yes, I did that. BWAHHAHAHAHAHAHAA.....-Bruce

You are a cad.

Cheers, John

 

[jneutron]

...I'd seen this thread earlier...imagine two of my heroes Rod Elliot and jneutron participating (???) in the same thread...it's a pity much of it is over my head, but then again what isn't...Quite interesting reading though...I love the interweb!

jimHJJ(...it causes me to look things up...BTW, g'day Bruce...)

Rod, I can understand..I love his website and all the info.

Me??? You gotta get a life, dude.. But don't ask me where..

Cheers, John

 

[mtrycrafts]

Don't get hung up on the 5 foot number.

Just something I can put my finger on and better see that soundstage jump an amount large enough to not call it head jerks or something else

A while ago, I had read (Roger Russel I believe) that the recommendation for wire guage vs distance for a speaker was based on the wire resistance being les than 5% of the speaker impedance, limiting the power loss to 5%. A reasonable number if there are no other consequences..

Yes, it is at his web site that is being posted frequently.

Oh, btw Gene....my tweets do not burn out at 10 watts nor 20..they are 2 inch voice coils in ferrofluid.

Cheers, John

Not sure he will read this.
Ok, so your tweeter will fail at 25watts

 

[jneutron]

Ok, so your tweeter will fail at 25watts

It's rated 150 watts program with a 2nd order xover at 2Khz.

I use a third order at 5Khz. So I can handle a bigger program.

Course, that still doesn't tell me what the tweet can actually handle..it's Selenium's way of hedging their bets...if it blows, they say "program". If it doesn't, they say "see".

But at 107 dBspl 1w/1 meter, it would get rather uncomfortable in a living room if pushed towards failure.. I use two in a 450 seat venue, and it gets loud enough thank you...

Cheers, John

ps...would it be possible for somebody to change "birwiring" to "bi-wiring"? It's driving me insane...(unfortunately, nobody's noticed)..

 

[Resident Loser]

Maybe...

...ps...would it be possible for somebody to change "birwiring" to "bi-wiring"? It's driving me insane...(unfortunately, nobody's noticed)..

...y'all are discussing the wrong thing...maybe it IS birwiring...I did a Google on birwiring and hot-diggity-dog, two pages of citations came up!!!!

jimHJJ(...and we all know the interweb is never wrong...right...)

 

[FLZapped]

And as I stated, it gives the wrong answers because in order to get an instantaneous current of +1 and -1 amp in the two legs, you'd have to have two sources.

Nah, that's not how it works. The tweeter and woofer must at some point in time, have equal and opposite currents, as they are orthogonal currents, meaning uncorrelated.

Then what is the output voltage of the amplifier? -Bruce

 

[jneutron]

Then what is the output voltage of the amplifier? -Bruce

Who cares??

The resistive loss within the wires has absolutely no concern for the voltage potential of either wire. It only deals with the current.

The instantaneous power that is going through the wire, of course relies on both the amp voltage and the current within the wire.

Note that I have chosen this scenario very carefully. I use one amp to guarantee that both the biwire and the monowire case receive the exact same voltage stimulus at the exact same time. That way, the losses that occur within the monowire case can be clearly defined with respect to that of the biwire currents.

Note also that the capacitor and inductive values are also of no concern to the problem..Once one assumes that the loads and the crossover values are identical, the problem is easy....if biwiring makes no difference, then how is it the wire carrying the current to the load dissipates power differently depending on mono/bi setup.


Cheers, John