Audiophiles Fail to Hear Difference in Signal Passed Through Copper Cable, Banana, and Tray of Mud

Does the “quality” of audio interconnects—cables that conduct an unamplified analog audio signal between components of an audio system—affect the listening experience? You’ll probably be unsurprised to learn that the answer is the subject of much debate: science suggests that any effect on the signal is inaudible; audiophiles, meanwhile, insist that they can hear the difference.

The latest salvo in this endless war comes from the forums of audio enthusiast site diyAudio (via Tom’s Hardware), where a forum member by the name of Pano devised a blind test to look at how much difference (if any) the material of an interconnect makes to signal quality.

To this effect, he presented four versions of the same 30-second audio sample: the original CD recording, and then looped recordings made after running the sound through a) about 70″ of “pro audio copper wire”; b) about 48″ of copper wire and 8″ of wet mud; and c) 48″ of copper wire and a 5″ banana. Forum members were challenged to listen to the various versions and then pick which was which.

They could not. Only six of the 43 responses submitted correctly identified the original recording or the one routed via audio cable, and at least one member consistently preferred banana music. Some, uh, spirited debate ensued as to how significantly the results differed from random guesses; statistics was never our favorite corner of mathematics, but happily, Tom’s Hardware crunched the numbers and concluded that “the results are consistent with randomness.”

It’s easy to present this as a way to make fun of audiophiles—and, indeed, there is something amusing about people who spend loads of money on fancy cables not being able to tell such a cable apart from a banana. But equally, it’s kind of amazing that you can get vaguely decent results routing audio via a banana or a bunch of mud in the first place.

It’s not so much that the signal traverses these mediums—both contain water, and while pure water doesn’t conduct electricity, the salts and other impurities dissolved into most water allow it to act as a conductor. (This is why the battery experiments you carried out at school always use salty water.) Soil presumably contains all manner of molecules that dissolve into water, while bananas famously contain a bunch of potassium.

The surprising thing is that they don’t appear to degrade the signal. Instead, as Pano notes, they simply reduce its level, effectively acting as resistors. “Banana and mud (and in the older tests, potato) are simply like putting a resistor in series, meaning that other than changing the signal level, they don’t do much.” He concluded that while shielding cables from external interference can affect audio quality, “What doesn’t seem to make much (if any) difference in sonic quality is the material of the conductor.”

There are also some fascinating tidbits of information to be extracted from the very serious eight-page discussion that ensued: the banana’s ripeness doesn’t appear to make a difference, the bananas were grown 68 meters away from the soil that was used to make the mud, and the following sentence now exists in the world: “There are many known physical effects that could affect cable sound which are not tested for by bananas nor by mud.”

You can have a listen to the files yourself—they’re available in FLAC and WAV format, and there are a variety of genres to choose from. For what it’s worth, we listened to the samples of Pink Floyd’s “Comfortably Numb” and Nirvana’s “Come As You Are”—via laptop speakers, to be fair—and couldn’t hear any difference.