Setting up an audio chain consists of several choices: first, the analogue / digital audio source (CD, LP, MP3) must be chosen; then the source device (CDP, turntables, MP3 players) which converts the data to sound must be selected, followed by an amplifier, which amplifies the signal from the source device to suitable levels, and finally the speaker / earphones / headphones must be chosen to convert the electrical signal to audible sound.


On the positive side, this represents a wide range of options for listening to music, but this may be a bit too much for novice audiophiles. In addition, there are other products that introduce further confusion – DACs, for instance, are sometimes mistaken in their function by new audiophiles. And one such product – and there is no shortage of confusion here – that we will be testing today is the cable.
For a theoretical discussion regarding cables, please refer to ”Cables & Sound Quality” – for those of you who are in a hurry, the conclusion is that ‘unless the manufacturer has purposefully designed the cable to introduce distortion, the cables have little effect on the sound’.
For today, we’ll look at how the sound of earphones change with different cables.


The candidates

The candidates for today’s testing are:
1. Ultimate Ears Default Cable
2. Ultimate Ears Custom Cable
3. Furetech Cable
I personally wanted to test the Lune cable as well, but unfortunately none were available for testing.


From the left, Ultimate Ears Default Cable, Ultimate Ears Custom Cable, Furetech Cable


 From the left, Ultimate Ears Default Cable, Ultimate Ears Custom Cable, Furetech Cable


From the left, Ultimate Ears Default Cable, Ultimate Ears Custom Cable, Furetech Cable


From the left, Ultimate Ears Default Cable, Ultimate Ears Custom Cable, Furetech Cable



Testing methodology

The testing methodology is simple: the cables will be swapped on Ultimate Ears triple.fi (M-Audio IE40) earphones, and the frequency response will be compared. If the sound does change, then the frequency response should reflect this, and if it does not, then the frequency response graphs will be identical.






The result for the Furetech cable was almost identical to the stock cable within error, but the Ultimate Ears Custom Cable shows some discrepancy in the treble range (less treble compared to stock).
Due to its characteristic impedance curve, the Ultimate Ears triple.fi 10 pro has a treble presence that weakens with additional impedance. With this in mind, I thought that the cable might have a different impedance value, and voila:
(for a more in-depth discussion of how the sound changes as impedance is added, consult the article on output impedance and the impedance graph)




Measuring the impedance on various cables, it is clear that while the stock and the Furutech cables share a nearly identical impedance curve, the U.E. Custom Cable has a higher impedance (by about 5 ohms) compared to either. The likely explanation is that the manufacturer added some impedance to make the Custom Cable sound different, and this is the cause for the weaker treble.




We see that there is little difference in sound between cables that have not been specifically treated. In case of the U.E. Custom Cable, the slight change in sound is due to the cable’s resistance, and the same effect could be achieved by adding a 5Ω resistor to the stock cables (or any other normal cable for that matter).
5Ω of resistance is a huge value for a cable, and this is what causes me to believe that the manufacturer added it purposefully.
(Default, Furetech Cable : 0.07Ω / UE Custom Cable : 4.8Ω)
‘High-end cables’ might still have some advantages in other areas such as cable texture, finish and durability, but not in sound.