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In the past Synergistic Research and other cable manufacturers have "split" a speaker cables geometry in half to provide separate leads for high and low frequency terminations. On the surface this seems the most logical choice and was our preferred method of bi-wiring for nearly 20 years. Theoretically this method for bi-wiring connects the amplifier to the filter halves (cross over) separately to prevent inter-modulation, generated by one driver, to influence the other driver.
However If you look at the damping factor that reduces the unwanted signals you find that they differ very little with or without cables (with 5 or 0 meter long cables for example). When using a tube amplifier, the cables in practice have no influence at all to damp the signals from one side of the filter to the other, because the damping factor is too low already in the power amp. The signal will slip through anyway to the other driver, despite the cables. Apart from that, a well-designed crossover filter will provide a certain protection against "leaking" inter-modulation since each half of the filter (cross-over in a two-way system) will damp each half of the frequency range.
Another way to bi-wire is to run two different cables in parallel thus giving the amplifier the ability to choose separate cables that are especially suitable for each half of the frequency range. This has been a hallmark of Synergistic Research cable design going back to our fist Signature speaker wire- The Signature No. 2. If you assume that the signal always takes the path of least resistance, the right path will be chosen automatically.
Disadvantages of the traditional Bi-Wire termination:
One thing that happens when you bi-wire your loudspeakers is that the input of the high- and the low-pass filters are fed with different input signals. The difference is a result of the high frequencies and the low frequencies being forced to travel different paths, perhaps through different types of cables, but under all circumstances through cables who have seen different loads (a tweeter with a high pass filter has a completely different impedance response compared to a woofer with a low pass filter!).
What happens is that the drivers do not integrate when their filter halves (crossovers) are fed with unequal signals. The result is the generation of phase error that effects the sound and transfer of phase information to the different drivers in a speaker. This phase error occurs because there will be non-linearity\\\'s in the low- and high-frequency paths.
What does this sound like? Well, usually, just as you would expect from physics, it appears as a change in the reproduction of space and sound staging. The impression after a week or month is that all recordings sound very much alike.
Integrated Frequency Termination (IFT) Bi-Wire:
All Tesla speaker wires from Vortex through Apex function as a lens to control electromagnetic inter-modulation and from Accelerator through Apex contain at least one Tricon lens geometry to precisely control electromagnetic fluctuations for perfect phase time transfer. IFT Bi-Wire ensures that your amplifier "sees" consistent loading from low through high frequencies for sound staging that is as expansive as it is precise. Low frequencies are further tuned in series with high frequencies through a transmission line precisely tuned to low frequency transfer that exactly matches it's speaker wire geometry.
Shotgun Bi-Wire vs. TESLA IFT Bi-Wire:
One option that does not take advantage of IFT Bi-Wire is a shotgun termination of two parallel speaker wires terminated to a common set of spade or bananas at the amplifier end. Obviously this option would deliver double the cost of bi-wiring your system when compared to IFT Bi-Wire but would it carry higher performance? The simple answer is "no." First by separating the high(er) frequencies from low frequencies the amplifier sees very different loads and transfers your music as a mis-matched signal with significant phase distortion to your speakers. It is as if you are "focusing" on the upper frequencies with a "wide-angle" lens and a the low frequencies with a "telephoto" lens. This presents high frequencies and low frequencies in different aspect ratios for a sound stage that sounds "bigger" in the upper registers then it does in the lower registers and this introduces sound staging problems. A far better option would be to spend the extra money on a higher end speaker wire with IFT Bi-Wire thereby elevating your systems presentation in an equal and balanced way.
If the manufacturer of your speakers insists on running separate speaker wires to the high and low frequency of your speakers binding posts we can arrange for you to audition two speaker cables in shot gun vs. the equivalent higher end speaker wire of approximately the same value with IFT Bi-Wire and allow you to make the final call as to which bi-wire option delivers higher performance.
IFT Bi-Wire vs. Jumper Cables:
So how is IFT Bi-Wire termination different from standard jumper cables or binding straps? Simple. Jumper cables are rarely tuned to the frequency range they will be called to transfer and are often times of a much lower quality then the speaker cables they are used with. Furthermore jumper cables introduce additional hardware in the form of spade lugs or banana plugs that further degrade the sound. Bi-wire binding straps are almost always worse then jumper cables as they are little more then plated metal of a quality and build that introduces considerable distortion in the form of harsh highs or muddy lows.
For the purpose of auditioning TESLA speaker wires many dealers opt for non-IFT Bi-Wire speaker models and will instead provide you with IFT Bi-Wire jumpers of the same nature as those found on our IFT Bi-Wire speaker cables. Aside from the addition of an extra set of connector hardware (spade or banana) the performance will be similar to that our IFT speaker cables but with slightly higher performance when you order speaker cables with IFT Bi-Wire built in.
Picture 1: From this graph you can se what damping factor and real damping you get with different cable lengths and different cables (2.5mm2) and different amplifiers. With a good transistor amp the damping will be decreased about 4 dB with a 5-metre long cable. With a good tube amp, the damping will lose about 2 dB (the original damping with the tube amp was about 14 dB less however).
Picture 2: These two curves show the cross talk from the woofer to the tweeter. Bi-wire for the lower curve.
Picture 3: The diagram for the simulation. The two components at the far left simulate the woofer resistance and inductance. The two next is the lowpass filter for the woofer. Of the next six components, the horizontal represents the two cables and the vertical represents the output impedance of the amplifier. The broken line converts from bi-wire to single wire. Therefrom come two components representing the high pass filter to the tweeter and five components representing the tweeter.
Picture 4: This simulation is based on the diagram of picture 3. Here you can see that a phase difference has arisen when biwiring is used. The reason why the phase difference is largest just above the cross over frequency is that the inductance of the cable resonates with the capacitance of the high pass filter when not the inductance of the low pass filter is available in this range as when single wire is used. The most probable reason to the capricious sound of biwiring is that on top of this steady state error another, transient induced phase error between the cables will appear when playing music. This changes the radiation pattern of the speaker with the music. The human ear is very sensitive to such phenomena.
Merchant Services
High End Audio
High End Home Theater
Audiophile Loudspeakers
Audio Cables
Audio Power Conditioning
Room Treatment
Audio Tweaks
Portable Audio
Trade-Ins & Demo
Acme Audio
Acoustic Revive
Audience
AudioEngine
Bybee
Denon
Furutech
Harmonic Technology
Jaton
Kaplan Cables
Luminance Audio
Marigo Labs
Modwright
Nuforce
Oyaide
Reference 3A
Slim Devices
Stereovox
Stillpoints
Synergistic Research
Usher
Walker Audio
Links
Links Page
Newsletter Archive
International Orders
International Ordering Information
In the past Synergistic Research and other cable manufacturers have "split" a speaker cables geometry in half to provide separate leads for high and low frequency terminations. On the surface this seems the most logical choice and was our preferred method of bi-wiring for nearly 20 years. Theoretically this method for bi-wiring connects the amplifier to the filter halves (cross over) separately to prevent inter-modulation, generated by one driver, to influence the other driver.
However If you look at the damping factor that reduces the unwanted signals you find that they differ very little with or without cables (with 5 or 0 meter long cables for example). When using a tube amplifier, the cables in practice have no influence at all to damp the signals from one side of the filter to the other, because the damping factor is too low already in the power amp. The signal will slip through anyway to the other driver, despite the cables. Apart from that, a well-designed crossover filter will provide a certain protection against "leaking" inter-modulation since each half of the filter (cross-over in a two-way system) will damp each half of the frequency range.
Another way to bi-wire is to run two different cables in parallel thus giving the amplifier the ability to choose separate cables that are especially suitable for each half of the frequency range. This has been a hallmark of Synergistic Research cable design going back to our fist Signature speaker wire- The Signature No. 2. If you assume that the signal always takes the path of least resistance, the right path will be chosen automatically.
Disadvantages of the traditional Bi-Wire termination:
One thing that happens when you bi-wire your loudspeakers is that the input of the high- and the low-pass filters are fed with different input signals. The difference is a result of the high frequencies and the low frequencies being forced to travel different paths, perhaps through different types of cables, but under all circumstances through cables who have seen different loads (a tweeter with a high pass filter has a completely different impedance response compared to a woofer with a low pass filter!).
What happens is that the drivers do not integrate when their filter halves (crossovers) are fed with unequal signals. The result is the generation of phase error that effects the sound and transfer of phase information to the different drivers in a speaker. This phase error occurs because there will be non-linearity\\\'s in the low- and high-frequency paths.
What does this sound like? Well, usually, just as you would expect from physics, it appears as a change in the reproduction of space and sound staging. The impression after a week or month is that all recordings sound very much alike.
Integrated Frequency Termination (IFT) Bi-Wire:
All Tesla speaker wires from Vortex through Apex function as a lens to control electromagnetic inter-modulation and from Accelerator through Apex contain at least one Tricon lens geometry to precisely control electromagnetic fluctuations for perfect phase time transfer. IFT Bi-Wire ensures that your amplifier "sees" consistent loading from low through high frequencies for sound staging that is as expansive as it is precise. Low frequencies are further tuned in series with high frequencies through a transmission line precisely tuned to low frequency transfer that exactly matches it's speaker wire geometry.
Shotgun Bi-Wire vs. TESLA IFT Bi-Wire:
One option that does not take advantage of IFT Bi-Wire is a shotgun termination of two parallel speaker wires terminated to a common set of spade or bananas at the amplifier end. Obviously this option would deliver double the cost of bi-wiring your system when compared to IFT Bi-Wire but would it carry higher performance? The simple answer is "no." First by separating the high(er) frequencies from low frequencies the amplifier sees very different loads and transfers your music as a mis-matched signal with significant phase distortion to your speakers. It is as if you are "focusing" on the upper frequencies with a "wide-angle" lens and a the low frequencies with a "telephoto" lens. This presents high frequencies and low frequencies in different aspect ratios for a sound stage that sounds "bigger" in the upper registers then it does in the lower registers and this introduces sound staging problems. A far better option would be to spend the extra money on a higher end speaker wire with IFT Bi-Wire thereby elevating your systems presentation in an equal and balanced way.
If the manufacturer of your speakers insists on running separate speaker wires to the high and low frequency of your speakers binding posts we can arrange for you to audition two speaker cables in shot gun vs. the equivalent higher end speaker wire of approximately the same value with IFT Bi-Wire and allow you to make the final call as to which bi-wire option delivers higher performance.
IFT Bi-Wire vs. Jumper Cables:
So how is IFT Bi-Wire termination different from standard jumper cables or binding straps? Simple. Jumper cables are rarely tuned to the frequency range they will be called to transfer and are often times of a much lower quality then the speaker cables they are used with. Furthermore jumper cables introduce additional hardware in the form of spade lugs or banana plugs that further degrade the sound. Bi-wire binding straps are almost always worse then jumper cables as they are little more then plated metal of a quality and build that introduces considerable distortion in the form of harsh highs or muddy lows.
For the purpose of auditioning TESLA speaker wires many dealers opt for non-IFT Bi-Wire speaker models and will instead provide you with IFT Bi-Wire jumpers of the same nature as those found on our IFT Bi-Wire speaker cables. Aside from the addition of an extra set of connector hardware (spade or banana) the performance will be similar to that our IFT speaker cables but with slightly higher performance when you order speaker cables with IFT Bi-Wire built in.
Picture 1: From this graph you can se what damping factor and real damping you get with different cable lengths and different cables (2.5mm2) and different amplifiers. With a good transistor amp the damping will be decreased about 4 dB with a 5-metre long cable. With a good tube amp, the damping will lose about 2 dB (the original damping with the tube amp was about 14 dB less however).
Picture 2: These two curves show the cross talk from the woofer to the tweeter. Bi-wire for the lower curve.
Picture 3: The diagram for the simulation. The two components at the far left simulate the woofer resistance and inductance. The two next is the lowpass filter for the woofer. Of the next six components, the horizontal represents the two cables and the vertical represents the output impedance of the amplifier. The broken line converts from bi-wire to single wire. Therefrom come two components representing the high pass filter to the tweeter and five components representing the tweeter.
Picture 4: This simulation is based on the diagram of picture 3. Here you can see that a phase difference has arisen when biwiring is used. The reason why the phase difference is largest just above the cross over frequency is that the inductance of the cable resonates with the capacitance of the high pass filter when not the inductance of the low pass filter is available in this range as when single wire is used. The most probable reason to the capricious sound of biwiring is that on top of this steady state error another, transient induced phase error between the cables will appear when playing music. This changes the radiation pattern of the speaker with the music. The human ear is very sensitive to such phenomena.
