Why Bi-wiring Makes No Sense.

[jonnythan]

While I cannot follow all of your equations I do see that in the best case they 'prove' a MINISCULE difference. Is it audible? You always side-step that question because you have better things to do with your time.

He has yet to show any difference at all between a monowire and bi-wire setup.

 

[jneutron]

From reading your posts on anything that has to do with wire and calculations I gather that you believe you are the only competent engineer on the whole planet as you *always* say 'you don't understand', 'where do these guys come up with this rubbish', etc..

Follow the context. We are discussing biwire, and what he described was not. If two people are going to have any meaningful discussion, both must be discussing the same thing. Since he came up with 16 ohm drivers, he is not discussing the same thing, biwiring. So, I ask, where did he get that from??

If that is what he believes biwiring is, then indeed, he doesn't understand.

Competent engineers abound. You gather incorrectly.

As for the 'where do these guys come up with this rubbish? You tell me where they get it from. So much of this "rubbish" comes from active imaginations, and have little to do with actual physics other than taking some physics words and recombining them into new sentences which the target market does not understand.

While I cannot follow all of your equations I do see that in the best case they 'prove' a MINISCULE difference.

Miniscule is in the ear of the beholder. If you consider 1% distortion to be miniscule, that is fine with me. Same with 5%... The fact that it is masked by the causative signal, and cannot be measured using standard techniques makes it so very difficult to understand..

What I speak of will eventually alter the recommended wire guages for speaker connections.. Not a big deal really...I'm not losing sleep over it.

What scares the technically minded people is not the equations or the results. What scares everybody is the fact that maybe the people who claim biwiring makes an audible difference, could actually be correct.. what a frightening concept indeed...that someone heard something that the EE community said was impossible..

Is it audible? You always side-step that question because you have better things to do with your time.

I do. And, it is of no concern to me. It changes my life not a whit.

What is far more important is that others learn how to look at a problem from a different vantage point. What has been learned in the EE programs should not be just memorization, but to learn how to think. Unfortunately, the thinking part is kinda difficult to instill without also introducing anarchy...the basis of the education process is to prevent anarchy and provide consistency. Too many get lost in that fact.

Cheers, John

 

[mtrycrafts]

..cables in kosher chicken fat

If Olive Oil is used, we don't have to worry about it being kosher or not, and is better for the heart

 

[jneutron]

I was using 8 and 16 to represent the speaker, whether or not those are real world numbers. Let me break it down for you.

Two 16 ohm loads in parallel gives you 8 ohms. Add the resistance in the single speaker wire running from the amp to the speaker terminal and you get 8.078 ohms.

Now, if you biwire, each of those 16 ohm loads instead of feeding them with a single wire, then you're dealing with two 16.078 ohm loads wired in parallel, giving you 8.039 ohms total.

Ok, so you broke it down...

Now, why are you using 16 ohm drivers? The term "biwire" does not mean swap two 16 ohm drivers in the place of the two 8 ohm ones..so why have you chosen that??

Here's a pic of biwiring so you understand what biwiring is with respect to this discussion..hope this helps.

Cheers, John

 

[mtrycrafts]

... Does anybody consider 1.95% to be below audibility? (this is just a calc of level of effect)

Cheers, John

You are so swift in math, , I will let you do the calcs, what is the dB spl loss and at what frequency? After all, that is crucial since JND is not linear. And, I think the spl level matters as well. Then, we might have an idea if that matters. But, then we need to compare that to something else as it certainly will not be to a 0 cable. then we have that delta difference to work with for audibility I think.

 

[jneutron]

You are so swift in math, , I will let you do the calcs, what is the dB spl loss and at what frequency? After all, that is crucial since JND is not linear. And, I think the spl level matters as well. Then, we might have an idea if that matters. But, then we need to compare that to something else as it certainly will not be to a 0 cable. then we have that delta difference to work with for audibility I think.

The issue is one of masking..the jnd's for this as applied to real music is lacking. The modulation has two impacts..first, it causes the hf content to appear to "breath", somewhat akin to (but not exactly like) port turbulence or voice coil gap turbulence.. It's a weird effect, actually, when using contrived signals. I've not tried to hear it with music, but I would expect that with my sound systems and music preferences, I wouldn't be very successful..Woolly Bully tain't exactly high end, now is it?

With actual music (god forbid), what is needed is testing for <i>differential </i>image positioning and flutter. And, the biggest caveat? Present day recorded material sucks in that regard. After all, what is the standard speaker spl, spacing, angular displacement, and throw pattern??

So for me, the advantage of biwiring is moot, I don't care..buuuut, there is a significant difference to some..

Cheers, John

 

[jneutron]

He has yet to show any difference at all between a monowire and bi-wire setup.

Alas, you choose not to see.

With time, you will. This discussion does indeed force me to plant all the dialogue onto a picture more suitable for teaching, so I do not consider this a waste of time, but rather it helps me learn how better to teach. That comes in handy for me at work..

It's interesting watching you waffle back and forth between anger and indignation and disbelief (perhaps not so deep as my words state, but that's my lack of good words.. ), and yet you have remained quite civil in your posts..I thank you for that, it has been my pleasure.

Examine the schematic, that is biwire..it should help you..we can pick this up tomorrow if you so choose.

Ah, just realized another point...don't worry about what the amplifier sees as a load. Consider the amp as a constant voltage source (very high damping factor).

Think instead of what is lost in the wires between the two wiring scenarios. What is lost is exactly the same in terms of RMS power loss, but not the same from one instant in time to the next. That is what the graph and the calcs show.


Cheers, John

 

[mtrycrafts]

You're not looking at the difference between "monowire" and bi-wire.

Using your numbers, and ignoring the wire in the amp:

An amp putting 100W into an 8 ohm speaker sees a total resistance of 8.078 ohms with a single wire.

An amp putting 100W into two parallel 16.078 ohm speakers sees a total resistance of 8.039 ohms, assuming *worst case scenario* of each speaker getting an equal amount of power (which is unlikely).

The difference in ohms? 0.48%. Assuming power stays constant, the difference in current is about 0.24%. I'm obviously not very well versed on how an amplifier works, and how much current and power will change with respect to each other, but it's abundantly clear to me that the *difference* between monowire and biwire is totally insignificant. Best case, where one driver is using all of the power, the difference is 0%.

If you are implying that the woofer is 8 ohms and the tweeter is 8 ohms, the amp still sees an 8 ohm load across the band, not a 4 ohm load, as the impedance is frequency dependent.

 

[mtrycrafts]

The issue is one of masking..the jnd's for this as applied to real music is lacking. The modulation has two impacts..first, it causes the hf content to appear to "breath", somewhat akin to (but not exactly like) port turbulence or voice coil gap turbulence.. It's a weird effect, actually, when using contrived signals. I've not tried to hear it with music, but I would expect that with my sound systems and music preferences, I wouldn't be very successful..Woolly Bully tain't exactly high end, now is it?

With actual music (god forbid), what is needed is testing for <i>differential </i>image positioning and flutter. And, the biggest caveat? Present day recorded material sucks in that regard. After all, what is the standard speaker spl, spacing, angular displacement, and throw pattern??

So for me, the advantage of biwiring is moot, I don't care..buuuut, there is a significant difference to some..

Cheers, John

I saw in your post that you call this power dissipation of x % in monowire but then you also bring up distortion? Is it IM distortion or power loss of some x dB spl? I think they are two separate issues. The wire causes IM distortion between frequencies?

The JNDs I was referring to was level related, with test tones, that has been published in JASA, once.
If now it is distortion of that magnitude of over 1%, that also depends on frequency and level.

 

[mtrycrafts]

Like surviving double black diamond glade slopes with my kids..sheesh, they're bulletproof..Luckily, I didn't pull a "Sonny".

Cheers, John

Much simpler to tell them to meet you at the junction with the single black diamond

 

[jneutron]

If you are implying that the woofer is 8 ohms and the tweeter is 8 ohms, the amp still sees an 8 ohm load across the band, not a 4 ohm load, as the impedance is frequency dependent.

The interesting thing is yes, it does indeed imply a constant impedance across the audio band. That however, considers only one signal, that of a sine.

When information is going to both drivers through the same wire, the currents add, but the power that is dissipated changes differently.

I will be the first to admit that it is weird..and completely contrary to what has been taught..The next pic (or coupla pics) I post will make the distinction clearer..

Cheers, John

 

[mtrycrafts]

This discussion does indeed force me to plant all the dialogue onto a picture more suitable for teaching, so I do not consider this a waste of time, but rather it helps me learn how better to teach. That comes in handy for me at work..
Cheers, John

One favor
When using colors in charts and backgrounds, darker, richer color lines, lighter backgrounds so there is more contrast, please.
Had a hard time with that last picture

 

[jneutron]

Much simpler to tell them to meet you at the junction with the single black diamond

Yes, it is.

But the bonding is not the same. My kids enjoy it when daddy has such problems where they do not. I have a more than healthy respect for life (and trees), and am not shy about face plants or sitting down when I get into trouble..they love that.. It's the same on the normal slopes, if I fall down in front of them, they cruise right up to me and stop very quickly...burying me in snow...

Those are the good times..I won't take those away from them

Cheers, John

 

[mtrycrafts]

. What is lost is exactly the same in terms of RMS power loss, but not the same from one instant in time to the next. That is what the graph and the calcs show.
Cheers, John

So, here you are saying a power loss, again, right? That is equal to a level loss, a volume loss, right? Not distortion as in THD?

 

[jneutron]

One favor
When using colors in charts and backgrounds, darker, richer color lines, lighter backgrounds so there is more contrast, please.
Had a hard time with that last picture

picky picky...It was very clear on my monitor...I used sharpies to clarify the lines...can't you see that???

Course, now I gotta clean the monitor..

Cheers, John

 

[jneutron]

So, here you are saying a power loss, again, right? That is equal to a level loss, a volume loss, right? Not distortion as in THD?

Yes. But imagine the highs being level modulated by the lows on the order of a percent or two. When the modulation signal is high level bass, and both channels have different bass lines, the level modulation of the highs is not balanced, but causes side flutter of an image. Current jnd tests do not look for this directly.

Cheers, John

 

[mtrycrafts]

picky picky...It was very clear on my monitor...I used sharpies to clarify the lines...can't you see that???

Course, now I gotta clean the monitor..

Cheers, John

Yes, I am picky Part of learning for me especially when I need to invoke my eyes as well

 

[mtrycrafts]

Yes. But imagine the highs being level modulated by the lows on the order of a percent or two. When the modulation signal is high level bass, and both channels have different bass lines, the level modulation of the highs is not balanced, but causes side flutter of an image. Current jnd tests do not look for this directly.

Cheers, John

OK. so if it is a level modulation, why would that level change not fall under the umbrella of level change that has been tested for before?
Is that instantaneous even perhaps the real issue? What or how long of an even that can be detected, firstly with test tones, then with what matters, music? Curious mind here. Hard head as well some sinking process is slower than others.
At least you are willing to explain what you know.

 

[mtrycrafts]

The interesting thing is yes, it does indeed imply a constant impedance across the audio band. That however, considers only one signal, that of a sine.

When information is going to both drivers through the same wire, the currents add, but the power that is dissipated changes differently.

I will be the first to admit that it is weird..and completely contrary to what has been taught..The next pic (or coupla pics) I post will make the distinction clearer..

Cheers, John

Is that frequency current additive in anywhere? Cable TV? Micro wave transmissions? Transmission lines for data? Then, you have an IM issue, no?

Can this be seen on a scope? A 50Hz signal and a 5kHz signal on the same wire. What will the scope show with time? What your picture explanation showed? Is that only a current behavior? Or will the voltage do that too?
If not, why one, not the other?

 

[mtrycrafts]

Yes, it is.

Those are the good times..I won't take those away from them

Cheers, John

Yes, they are but on a double D? WOW.