I read through the updated version of the article on
Stereophile. Was going to write a response but figured I ask ChatGPT what it thinks of the summary. That was right on the money so I am going to quote that:
This is a great example of a summary that is
partly grounded in real EM theory but drifts into speculation and overreach. I’ll go through it in a grounded, engineering sense.
What in this summary is
1) Geometry, inductance, and field distribution matter
Correct.
This is just standard transmission line theory:
- Inductance and capacitance depend on conductor spacing and geometry
- External fields dominate energy propagation
No controversy here.
2) Interleaving / twisting reduces interference and inductance
Correct.
That’s why we use:
- Twisted pair
- Star-quad
- Coax
This is well-established EMC practice.
3) Litz wire reduces AC resistance (under some conditions)
Conditionally correct:
- True at high frequencies where skin effect dominates
- Mostly irrelevant at audio frequencies for typical wire sizes
So this is technically correct but
contextually overstated for audio cables.
4) Lumped R, L, C models are approximations
Also true:
- At higher frequencies or long cables → distributed models matter
- But at audio + short cables → lumped models are usually extremely accurate
Where it becomes
1) “Conductors should be sufficiently thin…fraction of a wavelength trapped”
This sounds technical, but:
- Audio wavelengths are enormous
- 20 kHz → ~15 km wavelength
- Cable lengths are tiny in comparison
There is
no practical “wave trapping” issue inside conductors at audio frequencies in normal cables.
This is a
misapplied RF concept.
2) “External mechanical vibration modulating impedance”
This is theoretically possible (microphonics), but:
- In speaker cables → negligible
- In interconnects → only relevant in extreme high-impedance / tube circuits
For normal systems, this is
not a meaningful design constraint.
3) “Slow, frequency-dependent velocity in a conductor”
This is the
biggest source of confusion.
Yes:
- Fields inside a conductor propagate slowly (diffusion-like behavior)
But:
- That is NOT the signal path
- The actual signal travels in the dielectric at near light speed
The summary subtly implies:
That’s misleading.
Correct interpretation:
- The loss component is slow
- The signal itself is not
4) “High conductivity makes conductor appear larger on the inside”
This is a poetic way of describing
skin effect, but:
- Skin depth in copper at 20 kHz ≈ 0.46 mm
- That’s comparable to typical wire radii
Meaning:
- Skin effect exists
- But it is mild in audio cables, not extreme
5) Crystal boundaries and “current vortices”
This is where the article becomes speculative:
- Grain boundaries do affect conductivity slightly
- But:
- Effects are tiny
- Not modeled in practical cable design
- No evidence of audible impact
This is
not part of standard electrical engineering models
6) “TARDIS (Transient And Resistance Distortion)”
This is essentially a
coined term, not an accepted phenomenon.
- It loosely refers to time-domain effects from resistance + dispersion
- But:
- No standard definition
- No established magnitude
- No demonstrated audibility
Treat this as
conceptual speculation, not established theory
Bottom-line evaluation
The summary is:
Technically grounded in parts
- Field-based signal propagation
- Role of geometry
- Skin effect and losses
But
- Applies RF/microwave thinking to audio where it barely matters
- Emphasizes effects without quantifying magnitude
- Mixes established physics with speculative interpretations
The key reality check
For typical audio cables (even long speaker runs):
- Resistance dominates
- Inductance matters slightly
- Capacitance matters in edge cases
- Skin effect is small
- Internal conductor “slow waves” are negligible
None of the exotic effects described here are known to produce
audible differences under normal conditions.
Final verdict
Is the summary correct?
- Partially correct in physics
- Misleading in practical importance
- Speculative in its conclusions
If you want, I can quantify this (e.g., how big these effects actually are in dB or microseconds for a real cable). That usually makes it very clear what matters and what doesn’t.
----
I did ask it to quantify that and this is what it computed:
Great—let’s put real numbers on this so you can see the scale of each effect in a
typical speaker cable. I’ll use a concrete, realistic case:
- Cable length: 3 m (≈10 ft)
- Wire: 12 AWG copper (very common)
- Load: 8 Ω speaker
- Top audio frequency: 20 kHz
1) Resistance (the dominant effect)
- 12 AWG copper ≈ 5.2 mΩ/m
- Round-trip (out + back): 6 m → ≈ 31 mΩ
Voltage drop:
[
\frac{0.031}{8} \approx 0.39%
]
Level loss:
[
\approx -0.034 \text{ dB}
]
Audibility:
Essentially inaudible. You’d need ~0.2–0.3 dB to start noticing.
2) Inductance (real but small HF roll-off)
Typical zip cord:
Reactance at 20 kHz:
[
X_L = 2\pi f L \approx 2\pi (20000)(1.8\times10^{-6}) \approx 0.23\ \Omega
]
Relative to 8 Ω load:
[
\frac{0.23}{8} \approx 2.9%
]
HF attenuation:
≈
−0.25 dB at 20 kHz
Audibility:
- Borderline at best
- And only at the very top of hearing
3) Capacitance (usually negligible)
Typical:
Reactance at 20 kHz:
[
X_C = \frac{1}{2\pi f C} \approx 26.5\ \text{k}\Omega
]
Compared to 8 Ω:
4) Skin effect (what the article leans on)
Skin depth in copper at 20 kHz:
12 AWG radius:
So current distribution is slightly non-uniform.
Result:
- AC resistance increase ≈ +5–10% at 20 kHz
Apply that to our 31 mΩ:
Level change impact:
[
\text{tiny} ; (\approx 0.003 \text{ dB})
]
Audibility:
Zero.
5) “Slow propagation inside conductor” (the big claim)
This is the core of the Stereophile summary.
Key comparison:
- Signal propagation in dielectric:
~2 × 10⁸ m/s
- Delay over 3 m:
[
\frac{3}{2\times10^8} \approx 15\ \text{ns}
]
“Slow” diffusive component in conductor:
Even if we exaggerate:
→ delay ≈
1.5 µs
BUT:
- This is only a tiny fraction of the energy
- It appears as loss, not a separate audible echo
Convert to phase shift at 20 kHz:
[
1.5\ \mu s \Rightarrow 0.03 \text{ cycles} \approx 11^\circ
]
Sounds big—but:
That phase shift applies only to a
minuscule component of the signal.
Equivalent amplitude error:
- Typically < −80 to −100 dB
6) Time-domain “smearing” (TARDIS idea)
Let’s bound it conservatively:
- Energy stored in conductor dissipates with a short time constant
- Typical decay times: nanoseconds to microseconds
Compare to audio:
So any “memory” effect is:
- << 1% of a cycle
- At extremely low amplitude
Equivalent distortion:
- On the order of −100 dB or lower
7) Mechanical vibration effect
Let’s be generous:
- Suppose cable motion changes impedance by 0.01%
- That modulates signal at similar level
→
≈ −80 dB effect or smaller
Buried under:
- Amplifier distortion
- Speaker distortion (typically −40 to −60 dB)
Final scale comparison
| Effect | Magnitude | Audible? |
|---|
| Resistance loss | ~−0.03 dB |  No |
| Inductance HF rolloff | ~−0.25 dB @ 20 kHz | Barely |
| Capacitance | Negligible | No |
| Skin effect | ~0.003 dB | No |
| Internal “slow wave” | < −80 dB | No |
| “TARDIS” स्मearing | ~−100 dB | No |
| Mechanical vibration | ~−80 dB | No |
The key takeaway
The Stereophile summary focuses on
real but extremely small second-order effects.
When quantified:
- speaker nonlinearities
- room acoustics
- even tiny EQ changes
Bottom line
- The physics discussed is not wrong
- But the practical significance is negligible
- The article’s “interesting effects” live mostly in the −80 to −100 dB range
If you want, I can compare this directly to:
- headphone cables (where things get even smaller), or
- extreme cases (very long cables, high-impedance loads) where some of this might start to matter.
-----
Bottom line: these effects are real as is the computation (Maxwell equations, etc.). Just like Einstein's relativity theory, where the effects at our speed is negligible, so are the things Hawksford talks about. Cable become incredibly important and at times, complex to impossible to analyze at very high frequencies. Audio on the other hand, extends down to DC. Even its 20 kHz high frequency is considered "nothing" by any RF engineering.
www.audioholics.com
