We compared specialised audio cables with a cheap wire — and there was little difference
MyBroadband tested different audio cables, including a cheap wire, and found no noticeable difference for average consumers or even enthusiast-level audiophiles.
Many audio cable manufacturers make bold advertising claims about ultra-low resistance and gold plated connections to tell consumers that a cable will allow better sound quality.
To evaluate these claims, you should remember that an audio cable is simply a wire that carries an analogue electrical signal ranging from DC to around 20kHz.
A cable has many aspects that can influence sound quality, like resistance and capacitance.
The resistance of the cable should affect the amplitude of the signal equally over the whole frequency range.
The resistance is linked cable’s material, the thickness of the wire, and its length.
Higher resistance will mean less volume at the speakers or headphones.
We can also easily measure the capacitance of a cable with a multimeter. Capacitance should not matter unless the wire is very long or the capacitance is very high.
A very high capacitance on an extremely long cable can act as a low-pass filter, suppressing higher frequency sounds.
We measured the resistance and capacitance of different audio cables. We tested each one by generating pure sine waves at various frequencies using a computer sound card and inspecting the waveform on the other side with an oscilloscope.
The audio cables we tested included:
- An inexpensive generic aux cable
- An expensive short aux cable
- A headphone cable that came with a set of high-end headphones
- An inexpensive aux extension
- A cheap replacement headphone cable with a built-in microphone
- A generic guitar cable
- A cheap piece of 2.5mm² electrical wire
The guitar cable and the short expensive aux cable had less resistance than our Fluke multimeter could measure (0.01 Ohm).
The cheap aux cable fared the worst, with around 5 Ohm per meter.
When it came to capacitance, the results reversed themselves in most cases.
The guitar cable measured more than 600pF per meter, while the headphone cable and cheap aux measured closer to 200pF per meter.
While these numbers are interesting, their impact on sound quality is mostly irrelevant.
The worst cable we tested would need to be more than 400 meters long before the capacitance started affecting the audio spectrum. Even then, it would still be beyond most people’s hearing.
All the cables performed well when tested using the oscilloscope.
The cable with the mic did have a lower amplitude overall, which was most likely due to some built-in volume circuitry.
Even the cheap electrical wire’s performance was good enough to be used as an audio cable, with relatively low resistance and capacitance.
It should be noted that the electrical wire is not shielded, which makes it susceptible to interference and noise problems from external sources.
One of the factors that can have a much more significant effect on sound quality is broken cables.
Rather than worrying too much about a cable’s specifications, make sure it is decently constructed and flexible enough not to break easily.
Also, check for good quality connectors on both ends, preferably with strain relief.
Audio cable comparison
The table below provides an overview of our audio cable testing results.
You should note that the results, as mentioned, do not significantly affect audio quality. For audio output purposes, one wire is as good as any other.
Audio Cable Test Results | ||||||
Cable | Length | Resistance | Resistance per metre | Capacitance | Capacitance per metre |
Estimate Cutoff from PC sound card |
Guitar Cable | 2.1 m | <0.1 Ohm | <0.05 Ohm | 1270 pF | 605 pF | 3.9 MHz |
Expensive Aux | 0.5 m | <0.1 Ohm | <0.20 Ohm | 260 pF | 520 pF | 19.1 MHz |
Aux Extension | 1.2 m | 0.6 Ohm | 0.50 Ohm | 570 pF | 475 pF | 8.7 MHz |
Electrical Cable | 0.9 m | 0.5 Ohm | 0.56 Ohm | 230 pF | 256 pF | 21.6 MHz |
Headphone Cable | 3.1 m | 2.3 Ohm | 0.74 Ohm | 650 pF | 210 pF | 7.7 MHz |
Aux with microphone | 1.3 m | 3.9 Ohm | 3.00 Ohm | 620 pF | 477 pF | 8.0 MHz |
Cheap Aux | 1.8 m | 9.1 Ohm | 5.06 Ohm | 410 pF | 228 pF | 12.4 MHz |