Why Bi-wiring Makes No Sense.

[Seth=L]

Im not talking about the resistance of the cable.

The higher frequencies would see a high impedance on the cable going to the bass section of a bi-wired speaker. The opposite goes for the bass. Just like how robert harley had explained it in the book. Therefore, Just like he had also explained the seperate frequencies would take two seperate paths.

And ALSO like he had explained because the bass drivers would require more current than the other drivers the cable powering them would have a larger magnetic field around it which in theory could affect the high frequency cable due to induction. The same principle applies to not running your signal cables parallel to high voltage cables.

Perhaps before questioning and rolling your eyes at someone's quotes you should try to understand the science behind them.

OK, but what performance advantage does Bi-wiring offer? If you use one cable run straight to the speaker it would do exactly the same thing at the terminals of the speaker as it would if you bi-wired the speakers. The only difference it would make, if what you say is correct, is at which stage down the line it occurs. Unless I am missing something, but I have tried both ways and hear no advantages of bi-wiring.

 

[jonnythan]

I think this attachment really says it all.

 

[Seth=L]

I think this attachment really says it all.

Picture's worth a thousand words, thank you Jonnythan. You have illustrated my point about as clearly as it could ever be.

 

[Haoleb]

Not totally correct.
The voltage of that higher frequency is at the input terminal of the low section and vice verse at the high drivers.
AND, the slope of the crossover to each segment dictates how much current actually will be delivered to each driver. They are not brick filters, hence, you will get a pretty good amount of out of band currents in each section. It is that simple.

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

OK, but what performance advantage does Bi-wiring offer? If you use one cable run straight to the speaker it would do exactly the same thing at the terminals of the speaker as it would if you bi-wired the speakers. The only difference it would make, if what you say is correct, is at which stage down the line it occurs. Unless I am missing something, but I have tried both ways and hear no advantages of bi-wiring.

I dont say that Bi-wiring makes a difference. The only reason I joined in on this thread was to say that some of the points that are made in the book are completely valid. Thats all! Nothing more!

 

[Dolby CP-200]

OK, but what performance advantage does Bi-wiring offer? If you use one cable run straight to the speaker it would do exactly the same thing at the terminals of the speaker as it would if you bi-wired the speakers. The only difference it would make, if what you say is correct, is at which stage down the line it occurs. Unless I am missing something, but I have tried both ways and hear no advantages of bi-wiring.

Seth=L

Have you A&B it with the SPL db meter. Yes I know you have other priorities at the moment to rather spend $34.00 on a simple analogue SPL meter well maybe soon.

I’d just use an active crossover it’s got some nice features which the average bi-wire doesn’t have.

 

[Seth=L]

Seth=L

Have you A&B it with the SPL db meter. Yes I know you have other priorities at the moment to rather spend $34.00 on a simple analogue SPL meter well maybe soon.

I’d just use an active crossover it’s got some nice features which the average bi-wire doesn’t have.

To much money, and no point. I am confident the x-overs are fine in my NHTs, which aren't bi-wireable anyway. But I have owned buy-wireable speakers in the past.

 

[Seth=L]

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



I dont say that Bi-wiring makes a difference. The only reason I joined in on this thread was to say that some of the points that are made in the book are completely valid. Thats all! Nothing more!

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

 

[mtrycrafts]

Another thought

Hey Mtry,

It drips snake oil from cover to cover.

Maybe that oil is good to cook with? At campfires?

 

[Jack Hammer]

I understand the physical difference between bi-wiring and bi-amping, but aren't they kind of the same thing, except one uses two amps, the other uses one amp with a shared signal.

Wouldn't one 'quality' amp with lots of headroom basically offer the same benefit as two to one speaker(biwiring vs biamping)? Or is this just getting into the minutia of a signal?

Asking, not challenging,

Jack

 

[mtrycrafts]

...but the bass does.it,s also "warmer"with copper.silver seems to give essing{sibance} prob,s

Please explain it technically, not through a belief system. I bet others are curious as well. What is in that 20ga wire that will dissipate the bass, increase 'warmth' probably meaning it also decreases the high frequencies, right? And, sibilance issues? That is most interesting. That needs more tech talk, please.

 

[mtrycrafts]

I understand the physical difference between bi-wiring and bi-amping, but aren't they kind of the same thing, except one uses two amps, the other uses one amp with a shared signal.

Wouldn't one 'quality' amp with lots of headroom basically offer the same benefit as two to one speaker(biwiring vs biamping)? Or is this just getting into the minutia of a signal?

Asking, not challenging,

Jack

Well, to get the benefits of bi-amping, you need to eliminate the passive crossovers, use active ones. Then, you get the benefits promised. The passive crossovers are the culprits.
But, short of this, yes, your point is valid.

 

[jonnythan]

sibilance issues? That is most interesting.

See, silver is shinier.

So, it sounds brighter.

 

[Rowdy S13]

Ok I was just at the local audio store and saw a set of B&W 800 series speakers that were bi-Wired. Technicly I guess you would say they were bi-Amped. Either way it makes 0 sense to me. Inside the speaker is there two crossovers? One for the mid one for the tweeters? If thats true, why bother with 2 amps? If thats not true, why bother with the two sets of wires? Im not really into the technical part of it as much as alot of you guys, but like I said It makes no sense.

No matter HOW its hooked up, you still have to cut the freqency to each driver. A tweeter is not gonna play down to 20Htz so whats the difference if it has its own amp or own set of wires going to it? If you have two wires (comming from 2 seprate amps or 1 amp) into the speaker, the freqency still has to be limited to a certian range for each driver right?

I duno maybe Im over simplfying it, or maybe Im just not smart enough to grasp it all.

Sean

 

[jonnythan]

Ok I was just at the local audio store and saw a set of B&W 800 series speakers that were bi-Wired. Technicly I guess you would say they were bi-Amped.

There's a big difference.

In bi-wiring, you accomplish nothing.

In bi-amping, each speaker is getting its own amplification.

In a bi-{wireable,ampable} speaker, the two input terminals are hooked into totally different [passive] crossover networks. When biwiring or using the jumper, you are splitting the single-channel amp input in half and powering both separate networks with one signal.

When bi-amping, each amplifier's output goes to a totally independent crossover and driver(s).

So, yes, there *are* two individual crossovers in a bi-wireable speaker. When bi-wiring, the input of *both* is the single output of one amp. When bi-amping, each one is powered separately. I'm sure you can see how this would make a difference in the sound. A 100W input split in half, with half of each going through a crossover vs 100W discrete into each of two different crossovers.


100W ---> crossover that cuts low frequencies out ----> tweeter
|
----> crossover that cuts high frequencies out -----> woofer


VS

100W ---> crossover that cuts low frequencies out ----> tweeter

100W ---> crossover that cuts high frequencies out ----> woofer

 

[MDS]

IMO, Bi-amping but using the passive xover in the speakers is still suspect. It will be marginally better than single amping only because each driver gets its own separate amplifier and thus the high power demands of the woofer won't limit the power available for the tweeter. But, each driver will still see the entire frequency range and split out what it cannot deal with. So although you have a separate amp for each driver, those amps still amplify a full range signal and part of it is discarded by the xover in the speaker.

If you use active xovers, the xover will discard the portion of the signal that the driver to which it is destined won't use and the separate amps will only have to amplify a portion of the signal. The amp on the tweeter will only have to amplify the high frequencies and the amp on the woofer will only have to amplify the low frequencies. Each driver will only see the portion of the signal that it can deal with.

Think about your powered subwoofer. It discards the high frequencies *before* it amplifies the low frequencies. It doesn't have to amplify the portion of the signal that it will just discard. That is the equivalent of using active xovers before the amp.


If you bi-wire with a single amp and active xovers, that one amp will amplify a full range signal but the drivers will only see the portion of the signal that they can deal with.

Bi-wiring with a single amp and using the speaker's passive xovers accomplishes zip as has been stated many times already.

 

[Rowdy S13]

I guess I should have explained alil more. It was 2 seprate 2 channel McIntosh amps (1 2 channel for each speaker) So each driver had its own amp basicly. But besides being louder (100w per driver as opposed to 100w divided up between the drivers in a speaker) whats the advantage? Its STILL the same crossovers in the speaker cutting the same frequencys to each driver.

Sean

 

[Sheep]

the phasing wont be noticed {they move @light}but the bass does.it,s also "warmer"with copper.silver seems to give essing{sibance} prob,s

BS alert! High BS content. May cause Death.

SheepStar

 

[Sheep]

I guess I should have explained alil more. It was 2 seprate 2 channel McIntosh amps (1 2 channel for each speaker) So each driver had its own amp basicly. But besides being louder (100w per driver as opposed to 100w divided up between the drivers in a speaker) whats the advantage? Its STILL the same crossovers in the speaker cutting the same frequencys to each driver.

Sean

True Biamping uses active crossovers so the power going to each driver is only for the frequencies the driver is designed to play. It just gives you more headroom and the extra power needed for harder loads. It doesn't make midrange chocolaty smooth.

SheepStar

 

[MDS]

True Biamping uses active crossovers so the power going to each driver is only for the frequencies the driver is designed to play.

The short and sweet version of what I tried to say above. Thanks Sheep.

 

[Rowdy S13]

Ok so then the way they had it hooked up was BS. From what I saw it was a balanced input from who knows where (I think just a CD player into a pre amp at the back of the room, I think this because thats where I was controlling volume) and then just out from there to the speaker.

Sean