Why Bi-wiring Makes No Sense.

[mtrycrafts]

The voltage might be there but the current isint. Thats the whole point.

But the current is there as well, that is the point. The other driver tries to reproduce out of band signals and will as the crossover slope allows. And, since it is not a brick wall slope, you will get out of band sound. A 6dB/octave crossover (they do exist) will allow sound that is down 6 dB spl one octave above the crossover frequency, down 12 dB at 2 octaves.

 

[mtrycrafts]

Oh, I see. Well I was making more a point about the bi-wiring fallacy. The way it was worded was funny to me.

Not so fast
The crossover slope, 6db/octave, 12dB, etc, has an influence what that speaker will reproduce out of band. So, you will hear out of band signals in drivers, slope dependent as to volume. And, as best I know, this will happen with both setups?

 

[mtrycrafts]

See, silver is shinier.

So, it sounds brighter.

Yes, but that is not sibilance

 

[gene]

Regardless of what "Errors" a mono wire make compared to biwire, the error translates back to one common amp and gets washed out.

John, until you can actually prove audibility and show real world measurable differences in an actual system (real amp + real cable + real speakers), I maintain the main benefit of Bi-wiring (if any) is lower cable resistance but higher reactance. The simple solution is to use lower gauge wire and call it a day.

Redirect this energy towards:
Better speaker placement
integration of multiple subs
Active equalization (when needed)
Passive room treatments

Oddly most "preachers" of exotic cables (not saying you are one) and biwire champions rarely discuss the above issues that have a much more profound effect on audio quality.

PS. John, I hope you don't roast me too hard, I still luv ya man

 

[mtrycrafts]

PS. John, I hope you don't roast me too hard, I still luv ya man

What do you mean?
That next barbecue, you are the main course

 

[jneutron]

Regardless of what "Errors" a mono wire make compared to biwire, the error translates back to one common amp and gets washed out.

What??? I have absolutely no idea what you meant by that..

Nothing gets washed out..

PS. John, I hope you don't roast me too hard, I still luv ya man

There's never any barbacue sauce around when you need it..

Drew a pic and did an excel sheet to help others understand. I'm workin on translating the excel to something I can post, here's the support pic. The gist of the excel sheet shows the difference in powerloss between the two cases..

John, until you can actually prove audibility and show real world measurable differences in an actual system (real amp + real cable + real speakers), I maintain the main benefit of Bi-wiring (if any) is lower cable resistance but higher reactance. The simple solution is to use lower gauge wire and call it a day. .

Biwiring essentially allows much smaller wires to be used to avoid the issue I detail. It is an engineered solution to the problem, as opposed to simply tossing more copper in. ANYBODY can toss more copper in.

Gene, it's more important that others learn to see the problem from a different perspective..I refuse to hand out on a platter what is obvious when looked at from a different point of view. I'm sickened by the science educational level in the USA (it is that of a 12 year old), and prefer teaching others how to rethink. That takes much longer, but the results are far more rewarding.

I've demonstrated to myself the audibility, but using only contrived signals. Others can do the same, but real work towards testing audibility with speakers and actual (god forbid) music??... the industry has a bit to learn before they understand what to look for, where to look, and how to do it.


As for reactance, as I stated, I've left inductance out of the picture because it has been difficult enough for others to understand simple resistance based losses, you've no idea how complex it gets when the energy is stored then released to a branched load.

Redirect this energy towards:
Better speaker placement
integration of multiple subs
Active equalization (when needed)
Passive room treatments.

My energy is directed towards my life, my love, my kids, and my work. My hobby takes the back burner to all that. This entire biwire analysis, skin effect, transmission lines, line cords, they are all entities I use heavily in my work, which is why I have delved so far into them. But work goes from 3 to 6 orders of magnitude farther in all aspects.

As for room stuff...had an "expert" in a month ago to recommend stuff in the auditorium..I was not impressed...the guy liked and hawks gadgets and services, but did not have a technical understanding of the stuff..his forte w/r to what we needed was "room treatment"..that he knew well.

Oddly most "preachers" of exotic cables (not saying you are one) and biwire champions rarely discuss the above issues that have a much more profound effect on audio quality..

Hey, I duplicated valhalla speaker cables...it cost me 40 cents per meter..and made expensive double braids, about 2 dollars 34 cents per foot (not including labor). The merit exotic cables carry is basically L, R, and C. It's not rocket science.. Nor are the explanations or advantages always what is being touted by the vendors.

Cheers, John

 

[jneutron]

here's the excel in tst form..

Cheers, John

Look at the powerloss comparisons..I'll get back and edit this post to detail..
bummer, I note the columns didn't remain correct..case 2 powerloss totals moved to the right a bit..

 

[gene]

John;

It's more expensive and space consuming to run biwire pairs of equal gauge vs mono wire of 3AWG lower than the biwire pair. It's also way more practical to run a single wire to each speaker, especially surrounds.

Regarding my last comment about folding back to the amp, I was referring to the classic argument that biwiring eliminates HF/LF modulation in the cable since the wires are separate. This is moot since both pairs of wires lead back to a common amp where the signal is recombined.

Gene, it's more important that others learn to see the problem from a different perspective..I refuse to hand out on a platter what is obvious when looked at from a different point of view. I'm sickened by the science educational level in the USA (it is that of a 12 year old), and prefer teaching others how to rethink. That takes much longer, but the results are far more rewarding.

You know I always appreciate your perspectives, but you come off as if there is a night/day difference between each wiring scheme when its a simple matter of gauge differences and slight power losses due to resistance. I remind you that the I^2*R losses are far greater when a drivers voice coil heats up then a few milliohms of speaker cable resistance. You also never have equal current magnitudes going to the woofer and tweeter portion at the same time. Very little power is dissipated in a tweeter as most musical content sharply falls off above 8 kHz.

I agree with you about education level, which is why I pay extra for my child to goto private school as well as spending the time to educate here outside the classroom. My 6yr old knows more about the formation of Earth's moon, black holes and stellar phenomenon than most high school graduates

 

[Yamahaluver]

As an ex high school math teacher in public school NY, I fully concur with the above views on schooling crisis in USA. It was quite bad during my tenure, wonder what it is now, 12 grade students were just despicable and this was supposed to be in a moderately good neighborhood. You can see how US students do at various science and math Olympiads across the globe to get the depth of the situation.

 

[gene]

As for room stuff...had an "expert" in a month ago to recommend stuff in the auditorium..I was not impressed...the guy liked and hawks gadgets and services, but did not have a technical understanding of the stuff..his forte w/r to what we needed was "room treatment"..that he knew well.

Acoustics in Large vs Small rooms are completely different animals. You don't follow the same rules for both. The same applies for equipment usage as well. I forgot you deal mostly in large venues for sound reinforcement and don't delve much into the home theater realm.

 

[Nick250]

Biwiring essentially allows much smaller wires to be used to avoid the issue I detail. It is an engineered solution to the problem, as opposed to simply tossing more copper in. Cheers, John

It only took 150 posts to get to the bleedin' obvious.

Nick

 

[jneutron]

John;

It's more expensive and space consuming to run biwire pairs of equal gauge vs mono wire of 3AWG lower than the biwire pair. It's also way more practical to run a single wire to each speaker, especially surrounds.

Only if the biwire guages need to be close to that of a monowire. To reduce the dissipation modulation in a 2 way, 4 ohm flying load 100 feet from the rack, think about the numbers..1% level requires a loop resistance of 40 milliohms, 200 feet of copper (neglecting connectors) would have to be a #2 AWG wire. Quite impractical of course. (note, that is 100 C resistance, I don't have room temp copper values on hand, that's 30% lower but doesn't allow #4 AWG...)

Now, run biwire...there, you only have to worry about the overall RMS powerloss as there is no modulation ..5% loss in the wire is 200 milliohm loop resistance, or 1 milliohm per foot, that's a #10 wire..so 2 pairs of #10 vs one pair of #2? I'd go with the #10. It uses one third of the copper by weight that mono requires.

Regarding my last comment about folding back to the amp, I was referring to the classic argument that biwiring eliminates HF/LF modulation in the cable since the wires are separate. This is moot since both pairs of wires lead back to a common amp where the signal is recombined.

The signal does not recombine. the amp represents a node, and the currents all feed into it, but there is no recombination. Forget that, think only of the power loss difference.

You know I always appreciate your perspectives, but you come off as if there is a night/day difference between each wiring scheme when its a simple matter of gauge differences and slight power losses due to resistance. I remind you that the I^2*R losses are far greater when a drivers voice coil heats up then a few milliohms of speaker cable resistance. You also never have equal current magnitudes going to the woofer and tweeter portion at the same time. Very little power is dissipated in a tweeter as most musical content sharply falls off above 8 kHz.

Again, it's not rms loss that is of interest, it is the instantaneous loss. THAT is the result of the PRODUCT of the two signals that branch at the crossover.

I agree with you about education level, which is why I pay extra for my child to goto private school as well as spending the time to educate here outside the classroom. My 6yr old knows more about the formation of Earth's moon, black holes and stellar phenomenon than most high school graduates

Sheesh, that's a hot topic button, isn't it?.. It really pays to help them along at home, doesn't it?. I do that with my kids, they think I'm a nerd..(they're right, of course.. )

But my goodness, I give tours at the facilities here, and it's so dismal what the general public knows..

Cheers, John

 

[jonnythan]

Only if the biwire guages need to be close to that of a monowire. To reduce the dissipation modulation in a 2 way, 4 ohm flying load 100 feet from the rack, think about the numbers..1% level requires a loop resistance of 40 milliohms, 200 feet of copper (neglecting connectors) would have to be a #2 AWG wire. Quite impractical of course. (note, that is 100 C resistance, I don't have room temp copper values on hand, that's 30% lower but doesn't allow #4 AWG...)

Now, run biwire...there, you only have to worry about the overall RMS powerloss as there is no modulation ..5% loss in the wire is 200 milliohm loop resistance, or 1 milliohm per foot, that's a #10 wire..so 2 pairs of #10 vs one pair of #2? I'd go with the #10. It uses one third of the copper by weight that mono requires.

1% loss monowire needs 2AWG, but 5% loss biwire needs 10AWG?

 

[jneutron]

Acoustics in Large vs Small rooms are completely different animals. You don't follow the same rules for both. The same applies for equipment usage as well. I forgot you deal mostly in large venues for sound reinforcement and don't delve much into the home theater realm.

I deal with a large venue 7 times a year. My oldest does the mobile thing nowadays, and every so often I either lend some systems out, or do a gig for a friend. I have no desire to play gigs till 4 in the morning anymore, I have a real life.

Mentioning the expert only showed the level of understanding he brought to the table.. For room treatment, he was dynamite. For the sound prop/dispersion theory and application, he was amazingly weak.

My HT is a philips 5.1, with miniature speakers..it meets my need.

But the basic technology is rather the same, just the time scaling w/r to wavelength is different.

Cheers, John

 

[jneutron]

1% loss monowire needs 2AWG, but 5% loss biwire needs 10AWG?

Yes, although you've taken it out of context.

Monowiring incurs the 2AB component of dissipation, that is a modulation effect. Biwiring incurs only an efficiency loss. A pure efficiency loss is trivial in the scheme of things, just turn the knob up a bit..

Modulation of the loss cannot be compensated for.

Biwiring gets around the modulation, so the only thing left is efficiency and damping factor to worry about.

Edit:
Don't forget..when you are using a single driver, or a whole mess of them tied together series/parallel without any crossover..the wire does not introduce any distortion whatsoever...nada, nuttin. For that case, the only thing that matters at all is R, L, and C, the lumped parameters will affect the response as a typical low pass with loss.

It's when you put the crossover at the far end, that is when you setup the resistive loss modulation.. Then, you must set a specification of maximum modulation. I chose 1% for that level, but industry wide, nothing is known about this issue. That is who needs learn..

Cheers, John

 

[jneutron]

It only took 150 posts to get to the bleedin' obvious.

Nick

The obvious was always there. Why did it take you 150 posts to chime in?

Is the common inductance problem also so obvious to you?

Cheers, John

 

[gene]

John;

You are still assuming equal current magnitudes to HP and LP portions of the speaker. This doesn't happen. You also assume purely resistive loading (for simplicity) but this does affect power dissipation estimates and in this case I believe you scenario makes them worse off than reality. If you are talking instantaneous power loss then Yes the change in voice coil resistance is very relevant, moreso than cable resistance IMO.

We are splitting atoms here and I still maintain:

• Use a better single wire cable (10 AWG) vs 2 (12AWG) for biwire - easier to install, less system capacitance (assuming equally spaced conductors)

• Biamp instead of biwire when it makes sense

Here is a more in depth look at biwiring that makes for an interesting read:

http://www.st-andrews.ac.uk/~jcgl/Scots_Guide/audio/biwire/Page1.html

 

[jneutron]

John;

You are still assuming equal current magnitudes to HP and LP portions of the speaker. This doesn't happen. You also assume purely resistive loading (for simplicity) but this does affect power dissipation estimates and in this case I believe you scenario makes them worse off than reality.

Gene, Gene, Gene..you're not reading...tsk tsk.

Earlier in this thread, I pointed out:

1. The analysis assumes equal powers low and high, and this only occurs milliseconds before tweeter failure.

2. I stated resistive loading only, because the problem becomes considerably more complex otherwise. If you wish to get really into it, considering the loads as reactive causes the currents to go up as well as phase shift. Let's stick to simple for now..

My scenario is simply to show the fact that dissipation modulation is a fact of life when a monowire feeds a branched low impedance circuit. And, it can and does affect systems in a way that has been ignored.

We are splitting atoms here and I still maintain:

• Use a better single wire cable (10 AWG) vs 2 (12AWG) for biwire - easier to install, less system capacitance (assuming equally spaced conductors)

• Biamp instead of biwire when it makes sense

You also missed another point of mine...I use #12/2 runs for all my apps, up to 100 foot long runs. It works, it meets my requirements, I am not in the least concerned with the dissipative modulation for my own audio work.

I biamp when I need to. Never have I felt the need to biwire for an app.

However, that does not mean biwiring does nothing. It does indeed do something. It fixes what most people do not care about, nor are even aware exists. But if you are concerned with the virtual image presented to the listener in the sweet spot, then it is of concern. I personally am not one of those listeners, but understand what they look for.

Here is a more indepth look at biwiring that makes for an interesting read:

http://www.st-andrews.ac.uk/~jcgl/Scots_Guide/audio/biwire/Page1.html

Yes, I read that back in 2000 or 2001.. You note that it is the classic analysis, exactly what everybody else does..but yet, where is the loss in the wires, where is the modulation of that loss???

He does an excellent job of detailing exactly what has been taught in EE.

But he missed what I speak of..I've considered explaining to him what he neglected...maybe someday when it pays for me to do so.

As for you...well well, now what to do with you....

It is much better to understand what biwiring is, why it is needed, and when it is needed. Simply ignoring it as irrelevant is just as bad as claiming it is always needed. It is an engineering solution that has it's uses. And I've pointed out both.

Cheers, John

 

[Seth=L]

I am baffled it took so long to make this point clear. Why argue that bi-wiring has any purpose? It is more cost effective to just get a higher gauge from my understanding of these posts by Mtrycrafts, MDS, Clint, Gene, Jonnythan, or anyone one else that has made contributions to the argument against Bi-wiring. Higher cost defeats the purpose of bi-wiring, regardless if two 12 gauge cables perform better than just one. If you buy expensive 10 gauge wire and that becomes the argument, let that be your problem. I would sooner purchase Romex cable than high gauge snake oil crap.

The thread title is "Why Bi-wiring makes no sense". The way I see things, it still does not offer any advantage over traditional single wire configurations. I will admit that many posts made previously went way over my head, but there have been enough posts that I could understand the jest of it, Bi-wiring is not an efficient or effective way to connect speakers to an amplifier! Even in the circumstance that the amplifier doesn't have wiring running from it's output to the terminal. A sensible person would not bi-wire their speakers.

With that, I am finished. Let this thread take it's course.

 

[Seth=L]

it meets my requirements

I agree, it does for your requirements.