Bi wiring - Why does it work?

[Bodfish]

Disagree on the bi-amping front - that definately has more 'logic' to it than bi-wiring.

My view is the benefits of bi-wiring are down to removing the nasty metal plates that the manufacturers use to connect the treble and bass sections of the crossover. You are better off spending the money on a 'better' single run of cable and getting the cable manufacturer to make up a set of jumpers of the same type of cable to bridge the binding posts - many do this, Kimber, Chord and probably quite a few others too if you ask them.

Bi-amping works on the basis that each stereo leg of the amplifiers see only the bass or treble section of each of the crossovers. Each amplifier leg therefore only sees the load presented by that section of the crossover and may (depending on the load characteristics of the speaker) have an easier job of driving just that section.

But if you don't hear it, you don't hear it!!

 

[Anonymous]

Bodfish:
Disagree on the bi-amping front - that definately has more 'logic' to it than bi-wiring.

My view is the benefits of bi-wiring are down to removing the nasty metal plates that the manufacturers use to connect the treble and bass sections of the crossover. You are better off spending the money on a 'better' single run of cable and getting the cable manufacturer to make up a set of jumpers of the same type of cable to bridge the binding posts - many do this, Kimber, Chord and probably quite a few others too if you ask them.

Bi-amping works on the basis that each stereo leg of the amplifiers see only the bass or treble section of each of the crossovers. Each amplifier leg therefore only sees the load presented by that section of the crossover and may (depending on the load characteristics of the speaker) have an easier job of driving just that section.

But if you don't hear it, you don't hear it!!

Using two 50W amps and only getting the same power as one doesn't seem to me to be a sensible thing to do when you consider that most of the non-linearity and distortion is caused by the crossover. Either spend the money on one better amp or go active, IMO.

 

[Andrew Everard]

Although of course when biamping, the crossover is completely spilt in half, and each amp is only 'sees' a simplified filter network, rather than the entire crossover.

One just runs into a low-pass filter, for the bass, and the other into a high-pass filter, for the treble.

 

[hammill]

Red Dwarf:Bodfish:

Disagree on the bi-amping front - that definately has more 'logic' to it than bi-wiring.

My view is the benefits of bi-wiring are down to removing the nasty metal plates that the manufacturers use to connect the treble and bass sections of the crossover. You are better off spending the money on a 'better' single run of cable and getting the cable manufacturer to make up a set of jumpers of the same type of cable to bridge the binding posts - many do this, Kimber, Chord and probably quite a few others too if you ask them.

Bi-amping works on the basis that each stereo leg of the amplifiers see only the bass or treble section of each of the crossovers. Each amplifier leg therefore only sees the load presented by that section of the crossover and may (depending on the load characteristics of the speaker) have an easier job of driving just that section.

But if you don't hear it, you don't hear it!!

Using two 50W amps and only getting the same power as one doesn't seem to me to be a sensible thing to do when you consider that most of the non-linearity and distortion is caused by the crossover. Either spend the money on one better amp or go active, IMO.

I have an Onkyo 875 and have a 5:1 system (not 7:1) so I get Bi-amping for the cost of the cable.

 

[Tom Moreno]

The reasons (as they have been explained to me) for Bi-Wire/Amp etc come down to the physics of magnetic speaker movement. Mostly the travel of the lower frequency drivers.

As a driver travels in response to the electrons that are being sent to it by the power amplifier, it's own coil movement creates a distorted by-product signal that in normal conditions (non bi) find their way back to the other driver and cause it to not respond as perfectly as it can to the electrons being fed by the amp because of these interfering signals being generated by the woofer's coil. As a result if you lengthen the distance that these extremely low power signals being generated by the woofer has to travel to get to the HF driver (and vice-versa) these signals tend to dissipate along the length of the cable freeing up the HF driver and producing the most common audible effect of bi-wiring, better highs (which in turn effect our perception of soundstage and detail). This is because the amount of signal created by your LF driver's magnetic coil is greater than that created by your HF driver (simple inertia). Bi-amping takes this to it's fullest separation where there is no way for the singals created through coil movements in the woofer can find their way back to HF driver's signal chain. The best scenario is what you find in active studio monitors where we use an active crossover that feeds correctly band limited sound to individual amps for each driver via an internal speaker wire only a few inches long. From my understanding, some manufacturers have been working on high end crossovers for passive speakers that make great strides in reducing the amount of coil generated signal interacting between the drivers, I imagine that electronics of this type are likely being used in some of the aforementioned high-end speakers that are being offered with only one set of terminals.

 

[Bodfish]

Tom Moreno:

The reasons (as they have been explained to me) for Bi-Wire/Amp etc come down to the physics of magnetic speaker movement. Mostly the travel of the lower frequency drivers.

As a driver travels in response to the electrons that are being sent to it by the power amplifier, it's own coil movement creates a distorted by-product signal that in normal conditions (non bi) find their way back to the other driver and cause it to not respond as perfectly as it can to the electrons being fed by the amp because of these interfering signals being generated by the woofer's coil. As a result if you lengthen the distance that these extremely low power signals being generated by the woofer has to travel to get to the HF driver (and vice-versa) these signals tend to dissipate along the length of the cable freeing up the HF driver and producing the most common audible effect of bi-wiring, better highs (which in turn effect our perception of soundstage and detail). This is because the amount of signal created by your LF driver's magnetic coil is greater than that created by your HF driver (simple inertia). Bi-amping takes this to it's fullest separation where there is no way for the singals created through coil movements in the woofer can find their way back to HF driver's signal chain. The best scenario is what you find in active studio monitors where we use an active crossover that feeds correctly band limited sound to individual amps for each driver via an internal speaker wire only a few inches long. From my understanding, some manufacturers have been working on high end crossovers for passive speakers that make great strides in reducing the amount of coil generated signal interacting between the drivers, I imagine that electronics of this type are likely being used in some of the aforementioned high-end speakers that are being offered with only one set of terminals.

Well thank goodness that's cleared up then!

 

[Anonymous]

Tom Moreno:
The reasons (as they have been explained to me) for Bi-Wire/Amp etc come down to the physics of magnetic speaker movement. Mostly the travel of the lower frequency drivers.

As a driver travels in response to the electrons that are being sent to it by the power amplifier, it's own coil movement creates a distorted by-product signal that in normal conditions (non bi) find their way back to the other driver and cause it to not respond as perfectly as it can to the electrons being fed by the amp because of these interfering signals being generated by the woofer's coil. As a result if you lengthen the distance that these extremely low power signals being generated by the woofer has to travel to get to the HF driver (and vice-versa) these signals tend to dissipate along the length of the cable freeing up the HF driver and producing the most common audible effect of bi-wiring, better highs (which in turn effect our perception of soundstage and detail). This is because the amount of signal created by your LF driver's magnetic coil is greater than that created by your HF driver (simple inertia). Bi-amping takes this to it's fullest separation where there is no way for the singals created through coil movements in the woofer can find their way back to HF driver's signal chain.

If the cables are lossy enough to attenuate the fed back nasties from the woofer won't they also at least partially attenuate the signal that you want? If you use really good bi-wire cable isn't it effectively all connected together?

 

[Tom Moreno]

Red Dwarf:

If the cables are lossy enough to attenuate the fed back nasties from the woofer won't they also at least partially attenuate the signal that you want? If you use really good bi-wire cable isn't it effectively all connected together?

The level of this signal is very low. Imagine taking a speaker driver, and connecting it to another speaker driver and moving one driver enough to move the second. It is extremely small compared to the amount of signal created by a power amp. This combines with the fact that all speaker cable has signal loss, even the very best. The famous tests that speaker cable nay-sayers love to quote where a half-metre length of wire hanger sound as good as a high-end speaker cable at the such a short length are more proof that if you want great sound, reduce your cable run to the absolute minimum in order to lose as little signal as possible. This is why we use Active speakers in professional recording studios so that the amount of cable carrying fully-amplified signal is reduced to mere centimetres.

Therefore under these principles, the difference in distance this small amount amount of distortion has to travel between drivers to reduce efficiency becomes relevant when it is increased from (an approximate guestimate based on average systems) of .5-.75 metres in a floorstanding speaker (and even less in a bookshelf) that is not bi-wired, to a distance 4-6m in a full trip through a bi-wire setup.

 

[Anonymous]

Tarquinh:
lordmortlock:Tarquinh:
Actually,I think you're in luck. Spendor, Sonus Faber and Harbeth to my knowledge have all dropped biwireable speakers, so, assuming the trend continues, in 18 months or so it won't be an option anyway. The Harbeth designer actually admitted they'd only done it for marketing reasons.

But won't that make Bi amping more difficult?

Makes it virtually impossible without modifying the crossovers and adding extra binding ports.

I believe there is a move toward using series network crossovers instead of parallel. Which makes Bi anything virtually imposible.

Maybe I should try Quad wiring my old 4 way AR98's?

 

[SteveR750]

Tom Moreno:
The reasons (as they have been explained to me) for Bi-Wire/Amp etc come down to the physics of magnetic speaker movement. Mostly the travel of the lower frequency drivers.

As a driver travels in response to the electrons that are being sent to it by the power amplifier, it's own coil movement creates a distorted by-product signal that in normal conditions (non bi) find their way back to the other driver and cause it to not respond as perfectly as it can to the electrons being fed by the amp because of these interfering signals being generated by the woofer's coil. As a result if you lengthen the distance that these extremely low power signals being generated by the woofer has to travel to get to the HF driver (and vice-versa) these signals tend to dissipate along the length of the cable freeing up the HF driver and producing the most common audible effect of bi-wiring, better highs (which in turn effect our perception of soundstage and detail). This is because the amount of signal created by your LF driver's magnetic coil is greater than that created by your HF driver (simple inertia). Bi-amping takes this to it's fullest separation where there is no way for the singals created through coil movements in the woofer can find their way back to HF driver's signal chain. The best scenario is what you find in active studio monitors where we use an active crossover that feeds correctly band limited sound to individual amps for each driver via an internal speaker wire only a few inches long. From my understanding, some manufacturers have been working on high end crossovers for passive speakers that make great strides in reducing the amount of coil generated signal interacting between the drivers, I imagine that electronics of this type are likely being used in some of the aforementioned high-end speakers that are being offered with only one set of terminals.

Remember sound is "made" electronically by alternating current not DC, so there is no mass electron movement, only vibrations about a mean. It also travels at the speed of light (and on this reference at least the two camps of dual wave / particle scientists have agreed upon). So, in effect there are no time delays between a woofer or tweeter signal (unless your hearing is about 35.6 million times faster than CD sampling rate).

 

[Anonymous]

In he words of Vic and Bob:

"How does it work? It just does!"

"It's a Reeves and Mortimer product".

 

[Bodfish]

SteveR750:Tom Moreno:

The reasons (as they have been explained to me) for Bi-Wire/Amp etc come down to the physics of magnetic speaker movement. Mostly the travel of the lower frequency drivers.

As a driver travels in response to the electrons that are being sent to it by the power amplifier, it's own coil movement creates a distorted by-product signal that in normal conditions (non bi) find their way back to the other driver and cause it to not respond as perfectly as it can to the electrons being fed by the amp because of these interfering signals being generated by the woofer's coil. As a result if you lengthen the distance that these extremely low power signals being generated by the woofer has to travel to get to the HF driver (and vice-versa) these signals tend to dissipate along the length of the cable freeing up the HF driver and producing the most common audible effect of bi-wiring, better highs (which in turn effect our perception of soundstage and detail). This is because the amount of signal created by your LF driver's magnetic coil is greater than that created by your HF driver (simple inertia). Bi-amping takes this to it's fullest separation where there is no way for the singals created through coil movements in the woofer can find their way back to HF driver's signal chain. The best scenario is what you find in active studio monitors where we use an active crossover that feeds correctly band limited sound to individual amps for each driver via an internal speaker wire only a few inches long. From my understanding, some manufacturers have been working on high end crossovers for passive speakers that make great strides in reducing the amount of coil generated signal interacting between the drivers, I imagine that electronics of this type are likely being used in some of the aforementioned high-end speakers that are being offered with only one set of terminals.

Remember sound is "made" electronically by alternating current not DC, so there is no mass electron movement, only vibrations about a mean. It also travels at the speed of light (and on this reference at least the two camps of dual wave / particle scientists have agreed upon). So, in effect there are no time delays between a woofer or tweeter signal (unless your hearing is about 35.6 million times faster than CD sampling rate).

Dear Lord, my hearing is at least twice as fast as that...does this mean I will never ever hear the full potential of my equipment??