Audiophiles Struggle to Hear Differences Between Copper, Banana, and Mud Cables

A recent blind listening experiment has challenged long-standing assumptions in high-fidelity audio. Conducted on the diyAudio forum, the test asked participants to identify subtle differences in sound transmitted through traditional copper wire, a banana, or even wet mud. Results showed that even confident listeners were unable to reliably distinguish between the conductors.

The test used lossless audio files and accessible consumer equipment, making it replicable for hobbyists. Despite the unusual setup, guesses largely fell near random, suggesting that conductor material has little perceivable effect on short, line-level signals under typical listening conditions.

More than 3,000 forum members viewed the experiment, reflecting widespread curiosity about the potential impact of nontraditional audio connectors on sound quality.

Methodology and Setup

Participants were presented with four 30-second audio excerpts across rock, jazz, and classical genres. Each track represented a different conductor: the original CD file, a 180 cm loop of copper wire, 120 cm of copper combined with 20 cm of wet mud, and 120 cm of copper with 13 cm of banana. Files were provided in FLAC and WAV formats, and the test was fully blind, with guesses submitted privately.

The organizer noted the surprising similarity of the recordings. “The mud should sound perfectly awful, but it doesn’t,” they wrote. Importantly, the test did not rely on high-end audio equipment. It used standard consumer tools such as a laptop, USB audio interface, and basic recording software, making the experiment reproducible by anyone with an interest in audio testing.

Results Show No Clear Pattern

Across multiple participants, listener accuracy was effectively random. Only one beta tester—using a finely tuned, high-resolution system—showed a modest ability to identify the original tracks. Even in that case, the margin of success was minimal.

Slight preferences for the banana recordings appeared among some listeners, but these did not correlate with correctness. A summary table of guesses shared by the organizer confirmed that correct identifications were sporadic, underscoring the limited perceptual impact of conductor material in this context.

Why Unusual Conductors Often Sound Similar

At line-level audio, nontraditional conductors such as bananas or mud primarily introduce small amounts of resistance and minor capacitance. These changes may slightly reduce signal level or alter treble response, but do not create a distinct “signature” detectable in blind listening tests.

Previous forum experiments with materials including potatoes and carrots produced similar outcomes. Audio engineer Julian Krause tested a baby carrot as an RCA adapter in late 2024, observing only minor measurable effects—a 4–6 dB signal drop and slight treble boost—without audible differences under normal listening conditions.

When Conductor Material Can Matter

The experiment does not suggest that conductor material is universally irrelevant. It remains significant in certain scenarios:

• High-power signals: Long speaker runs carrying amplified signals can show tonal shifts due to resistance or capacitance.

• Extended cable lengths: Even line-level signals can experience high-frequency loss over very long runs.

• Ultra-sensitive systems: Low-noise, high-resolution equipment may reveal subtle differences.

• Interference-prone environments: Poorly shielded cables can pick up noise, affecting signal integrity.

For most typical listening situations, however, detecting differences without visual cues or preconceptions proves challenging. The experiment reinforces a broader point: many marketed claims about expensive or exotic cables may exaggerate perceptible benefits.

The diyAudio blind test highlights the resilience of line-level audio signals and emphasizes that, in the absence of labels and expectation, even unconventional conductors like mud and bananas are unlikely to produce reliably audible differences.