Pausi
Active Member
Hi, fellow Audio Science Heads!
Fyne Audio makes some interesting and often genuinely well-engineered loudspeakers. The company has substantial former Tannoy engineering heritage, including Dr Paul Mills, and many of its design ideas are recognisably in that lineage. Their F502S, for example, use a 200 mm IsoFlare point-source driver and a downward-firing port with a BassTrax Tractrix diffuser, both of which are acoustically plausible engineering approaches.
That said, I find the mixture of acoustic engineering and more speculative audiophile claims frustrating. In particular, I am interested in Fyne’s SuperTrax and S-Trax supertweeters, their cryogenic treatment claims, and the SC1 cable claims. The question is whether the claimed audible benefits are supported by controlled measurements.
I would especially like to hear from members who have performed bench testing, acoustic measurements, impedance sweeps, distortion measurements, or controlled listening tests on the SuperTrax, S-Trax, cryogenically treated crossovers, or SC1 cable.
Below are some technical thoughts.
The 360-degree radiation idea is not inherently unreasonable. High frequencies beam strongly from conventional forward-firing radiators, and an omnidirectional device could plausibly change the room’s high-frequency reflected field. The important question is what listeners are actually hearing.
For normal air-conducted hearing, the commonly cited young, healthy human range is roughly 20 Hz to 20 kHz, with high-frequency sensitivity varying strongly by age, sound level, and individual hearing condition. For many adult listeners, useful sensitivity above 16 kHz is limited or absent. So I am skeptical that the benefit, if audible, comes from direct perception of ultrasonic content.
A more plausible explanation is that these units affect the upper audible band and the room’s response. A 16 kHz high-pass is not a brick-wall filter. If the electrical filter behaves like a textbook 3rd-order Butterworth high-pass, it is about -3 dB at 16 kHz, about -8 dB at 12 kHz, and about -18 dB at 8 kHz. The real acoustic result will depend on the driver, impedance, level setting, placement, and interaction with the main loudspeaker.
This means that even with standard 44.1 kHz PCM sources, whose Nyquist frequency is 22.05 kHz, the supertweeter can still change the audible 12 to 20 kHz region. What a listener hears may therefore be “more air” or “more space,” but that does not require ultrasonic audibility. It may simply be changed upper-treble dispersion, changed room energy, or level mismatch.
There is also the question of intermodulation distortion. Ultrasonic content can produce audible intermodulation products if it passes through nonlinear electronics, amplifiers, DAC output stages, or transducers. I would not claim this always happens, but it is a real failure mode worth measuring. A useful test would be high-resolution playback with ultrasonic tones, measured acoustically and electrically, to check whether difference products appear in the audible band.
So my current view is:
The supertweeter hardware is real and testable. The 360-degree dispersion concept is acoustically plausible. But the likely audible mechanism is changed upper-treble response and room power response, not perception of anything ultrasonic.
Cryogenic treatment is not “fake” as a general industrial process. It has legitimate uses in metallurgy, especially for some steels where retained austenite and wear properties may be relevant. But audio crossover components and copper conductors are a different claim.
For copper at room temperature, electron-phonon scattering is a major contributor to resistivity, while impurities, grain boundaries, defects, and boundaries contribute residual scattering. Modern copper transport literature still discusses Matthiessen’s rule in terms of independent scattering processes, including electron-phonon and boundary scattering.
The relevant audio question is therefore simple:
Does cryogenic treatment measurably change R, L, C, ESR, dielectric absorption, distortion, microphony, or noise at room temperature?
If yes, show the before-and-after measurements. If no, then claims of “more refined,” “more transparent,” or “more natural” sound are not supported by evidence.
I would be especially interested in:
But if the claim is that ordinary copper conductors transmit speaker-level AC better in one direction than the other, that would require extraordinary evidence.
Audio signals in speaker cables are alternating current (AC). A normal homogeneous copper conductor should not have meaningful polarity-dependent conduction at audio frequencies. Any real direction-dependent conduction effect would imply nonlinearity or rectification, which should be easy to measure as distortion or waveform asymmetry.
Skin effect is also not a directionality argument. Skin depth in copper at 20 kHz is about 0.46 mm, and skin effect depends on frequency, conductivity, and magnetic permeability, not on which way the cable is installed. At audio frequencies, skin effect may slightly increase AC resistance in some conductor geometries, but it is symmetric with respect to current direction.
So my current view is:
Cable arrows are technically meaningful if they refer to shield or drain-wire grounding. They are not evidence that copper itself conducts audible AC better in one direction.
My concern: The hardware is real and the 360-degree dispersion concept is plausible, but the audible effect is more likely to come from changed upper-audible treble response and room response between roughly 12 and 20 kHz than from anything that is ultrasonic.
Fyne claim: Deep Cryogenic Treatment improves crossover and cable performance by relieving internal stress and improving signal purity.
My concern: Cryogenic treatment has legitimate industrial uses, but for room-temperature audio crossovers and copper conductors, the relevant question is whether R, L, C, ESR, distortion, or noise measurably change. I have not seen controlled before/after evidence demonstrating any audible or longevity benefit.
Fyne claim: The SC1 cable improves performance and directional installation is beneficial.
My concern: If the orientation relates to grounding or shielding, that can be technically legitimate. If the claim is directional conduction in copper for speaker-level AC, that should be measurable as nonlinearity or asymmetry.
My bottom line:
Fyne’s loudspeaker engineering deserves measurement-based discussion. But the claims around ultrasonic benefits, cryogenic treatment, and cable directionality need controlled measurements before I would treat them as established audio science.
Has anyone here measured these units or compared them under controlled, level-matched conditions?
Fyne Audio makes some interesting and often genuinely well-engineered loudspeakers. The company has substantial former Tannoy engineering heritage, including Dr Paul Mills, and many of its design ideas are recognisably in that lineage. Their F502S, for example, use a 200 mm IsoFlare point-source driver and a downward-firing port with a BassTrax Tractrix diffuser, both of which are acoustically plausible engineering approaches.
That said, I find the mixture of acoustic engineering and more speculative audiophile claims frustrating. In particular, I am interested in Fyne’s SuperTrax and S-Trax supertweeters, their cryogenic treatment claims, and the SC1 cable claims. The question is whether the claimed audible benefits are supported by controlled measurements.
I would especially like to hear from members who have performed bench testing, acoustic measurements, impedance sweeps, distortion measurements, or controlled listening tests on the SuperTrax, S-Trax, cryogenically treated crossovers, or SC1 cable.
Below are some technical thoughts.
SuperTrax and S-Trax supertweeters
Fyne’s SuperTrax is specified as a 16 kHz to 60 kHz supertweeter using a 25 mm Thin Ply Carbon Diaphragm driver, a 3rd-order high-pass crossover at 16 kHz, 8 ohm nominal impedance, and ±3 dB level adjustment. The smaller S-Trax is specified as a 16 kHz to 50 kHz unit using a 25 mm magnesium dome, also with a 3rd-order high-pass crossover at 16 kHz, 8 ohm nominal impedance, and ±4.5 dB level adjustment. Both use an upward-firing driver and a 360-degree diffuser concept.The 360-degree radiation idea is not inherently unreasonable. High frequencies beam strongly from conventional forward-firing radiators, and an omnidirectional device could plausibly change the room’s high-frequency reflected field. The important question is what listeners are actually hearing.
For normal air-conducted hearing, the commonly cited young, healthy human range is roughly 20 Hz to 20 kHz, with high-frequency sensitivity varying strongly by age, sound level, and individual hearing condition. For many adult listeners, useful sensitivity above 16 kHz is limited or absent. So I am skeptical that the benefit, if audible, comes from direct perception of ultrasonic content.
A more plausible explanation is that these units affect the upper audible band and the room’s response. A 16 kHz high-pass is not a brick-wall filter. If the electrical filter behaves like a textbook 3rd-order Butterworth high-pass, it is about -3 dB at 16 kHz, about -8 dB at 12 kHz, and about -18 dB at 8 kHz. The real acoustic result will depend on the driver, impedance, level setting, placement, and interaction with the main loudspeaker.
This means that even with standard 44.1 kHz PCM sources, whose Nyquist frequency is 22.05 kHz, the supertweeter can still change the audible 12 to 20 kHz region. What a listener hears may therefore be “more air” or “more space,” but that does not require ultrasonic audibility. It may simply be changed upper-treble dispersion, changed room energy, or level mismatch.
There is also the question of intermodulation distortion. Ultrasonic content can produce audible intermodulation products if it passes through nonlinear electronics, amplifiers, DAC output stages, or transducers. I would not claim this always happens, but it is a real failure mode worth measuring. A useful test would be high-resolution playback with ultrasonic tones, measured acoustically and electrically, to check whether difference products appear in the audible band.
So my current view is:
The supertweeter hardware is real and testable. The 360-degree dispersion concept is acoustically plausible. But the likely audible mechanism is changed upper-treble response and room power response, not perception of anything ultrasonic.
Deep Cryogenic Treatment and crossover claims
Fyne describes cryogenic treatment as part of its higher-end crossover and cable processes, and the SuperTrax and S-Trax pages refer to cryogenically treated or CryoLite-treated crossovers. Dealer and distributor descriptions of the SC1 cable also describe deep cryogenic treatment of the cable assembly.Cryogenic treatment is not “fake” as a general industrial process. It has legitimate uses in metallurgy, especially for some steels where retained austenite and wear properties may be relevant. But audio crossover components and copper conductors are a different claim.
For copper at room temperature, electron-phonon scattering is a major contributor to resistivity, while impurities, grain boundaries, defects, and boundaries contribute residual scattering. Modern copper transport literature still discusses Matthiessen’s rule in terms of independent scattering processes, including electron-phonon and boundary scattering.
The relevant audio question is therefore simple:
Does cryogenic treatment measurably change R, L, C, ESR, dielectric absorption, distortion, microphony, or noise at room temperature?
If yes, show the before-and-after measurements. If no, then claims of “more refined,” “more transparent,” or “more natural” sound are not supported by evidence.
I would be especially interested in:
- Before/after capacitor ESR and capacitance measurements.
- Before/after inductor DCR and inductance measurements.
- Before/after crossover transfer function measurements.
- Null tests between cryo and non-cryo assemblies.
- Distortion measurements at realistic drive levels.
- Thermal cycling stress inspection of solder joints and composite components.
SC1 cable and cable directionality
Fyne’s SC1 cable is marketed as an upgrade cable for SuperTrax and S-Trax, with upgraded conductor materials, an additional earth/ground lead, and cryogenic treatment. If orientation arrows simply indicate shield or ground orientation, that can be technically legitimate. Directional grounding can matter in some single-ended shielded interconnect arrangements.But if the claim is that ordinary copper conductors transmit speaker-level AC better in one direction than the other, that would require extraordinary evidence.
Audio signals in speaker cables are alternating current (AC). A normal homogeneous copper conductor should not have meaningful polarity-dependent conduction at audio frequencies. Any real direction-dependent conduction effect would imply nonlinearity or rectification, which should be easy to measure as distortion or waveform asymmetry.
Skin effect is also not a directionality argument. Skin depth in copper at 20 kHz is about 0.46 mm, and skin effect depends on frequency, conductivity, and magnetic permeability, not on which way the cable is installed. At audio frequencies, skin effect may slightly increase AC resistance in some conductor geometries, but it is symmetric with respect to current direction.
So my current view is:
Cable arrows are technically meaningful if they refer to shield or drain-wire grounding. They are not evidence that copper itself conducts audible AC better in one direction.
Summary
Fyne claim: SuperTrax and S-Trax extend response above the normal human hearing range and improve spaciousness, air, and realism.My concern: The hardware is real and the 360-degree dispersion concept is plausible, but the audible effect is more likely to come from changed upper-audible treble response and room response between roughly 12 and 20 kHz than from anything that is ultrasonic.
Fyne claim: Deep Cryogenic Treatment improves crossover and cable performance by relieving internal stress and improving signal purity.
My concern: Cryogenic treatment has legitimate industrial uses, but for room-temperature audio crossovers and copper conductors, the relevant question is whether R, L, C, ESR, distortion, or noise measurably change. I have not seen controlled before/after evidence demonstrating any audible or longevity benefit.
Fyne claim: The SC1 cable improves performance and directional installation is beneficial.
My concern: If the orientation relates to grounding or shielding, that can be technically legitimate. If the claim is directional conduction in copper for speaker-level AC, that should be measurable as nonlinearity or asymmetry.
My bottom line:
Fyne’s loudspeaker engineering deserves measurement-based discussion. But the claims around ultrasonic benefits, cryogenic treatment, and cable directionality need controlled measurements before I would treat them as established audio science.
Has anyone here measured these units or compared them under controlled, level-matched conditions?
References
- Fyne Audio, F502S product specifications.
- Fyne Audio, SuperTrax product specifications.
- Fyne Audio, S-Trax product specifications.
- Floyd E. Toole, Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms, 3rd ed., Routledge.
- Eberhard Zwicker and Hugo Fastl, Psychoacoustics: Facts and Models, Springer.
- Charles Kittel, Introduction to Solid State Physics, 8th ed., Wiley.
- John David Jackson, Classical Electrodynamics, 3rd ed., Wiley.
