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Glossary

THD

Total Harmonic Distortion — the percentage of a reproduced audio signal that is unwanted harmonic content. Lower is better. Hi-Fi targets THD < 0.1%; cheap drivers run 1–5%.

When a driver receives a pure sine wave, an ideal speaker reproduces the same sine wave. A real speaker adds harmonics — distortion. THD quantifies that addition as a percentage of the signal.

What's audible

  • < 0.1% — inaudible on transient material.
  • 0.1–1% — audible only on tones, not music.
  • 1–3% — adds warmth, often perceived as pleasant on tube-amp setups.
  • > 5% — audible as harshness, especially at high SPL.

In the spec sheet

Manufacturers quote THD at 1 kHz at moderate SPL — the easy case. The honest number is across the frequency range and at near-max SPL. Quality reviews measure across the band.

Buyer context

How to use THD in a real comparison

Total Harmonic Distortion — the percentage of a reproduced audio signal that is unwanted harmonic content. Lower is better. Hi-Fi targets THD < 0.1%; cheap drivers run 1–5%. In practice, this is most useful as one part of a decision rather than a standalone quality badge. Compare it alongside the workload, room, ecosystem, budget, and ownership constraints that apply to you; the strongest published figure is not automatically the best outcome for every buyer.

What to check next

Open a product page and check the stated value, configuration, price, and related trade-offs before treating this term as decisive. It is especially relevant in .

Avoid the one-number trap

Manufacturers can describe the same capability under different conditions. Compare like-for-like variants, check the unit and test condition where available, and use a head-to-head page to see whether a measurable difference is material for your own use.

vsMars presents structured catalog values to make trade-offs legible. The linked product and spec pages are the right place to inspect the underlying values before buying.

Where this matters

Categories that use thd

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