Overview

The Audio-Technica ATH-CK5 is a wired in-ear earphone released around 2005. It was positioned as an affordable product in its price range at the time. It features basic specifications including 14-24,000Hz frequency response, 20-ohm impedance, and 104dB/mW output sound pressure level, with accessories including three sizes of rubber sleeves, a cloth carrying bag, and an extension cable. Currently discontinued, it is only available in some used markets.

Scientific Validity

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According to catalog specifications, the frequency response is 14-24,000Hz, output sound pressure level 104dB/mW, and impedance 20 ohms. Although measurement data is limited, insufficient low-frequency reproduction has been confirmed from user reports of the time. This significantly deviates from the transparent level standard of 20Hz-20kHz (±0.5dB). THD and detailed S/N ratio data are not available, but considering the 2005 technical standards, it would be difficult to meet modern transparent level criteria (THD<0.01%, S/N ratio>105dB). The catalog specification upper limit of 24kHz also exceeds the modern standard of 20kHz, suggesting high-frequency-biased characteristics.

Technology Level

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As a budget product of its time, the ATH-CK5 was constructed using a combination of generic off-the-shelf drivers and basic circuit design. No unique technological development or advanced design elements are evident, and it cannot be said to reflect Audio-Technica’s technical capabilities. Compared to 2025 technical standards, it is significantly outdated in all aspects of driver technology, acoustic design, and materials engineering. The technical level is below industry average standards and inferior to modern entry-level products.

Cost-Performance

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As a modern product with equivalent or superior functionality and performance to the ATH-CK5, the 7Hz Salnotes Zero (20 USD) can be cited. The 7Hz Salnotes Zero has 10-20,000Hz frequency response, THD<1%@1kHz, and 108dB/V@1kHz output sound pressure level, achieving measurement performance superior to the ATH-CK5. The ATH-CK5’s 2005 retail price was approximately 26.96 USD (equivalent to about 20 USD at the time). The cost-performance calculation is 20 USD ÷ 20 USD = 0.98. Rounded to 1.0, the ATH-CK5 had world-class lowest pricing for its time. However, since it is currently discontinued and unavailable for purchase, practical cost-performance evaluation is meaningless.

Reliability & Support

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Audio-Technica has certain reliability as an established audio manufacturer, but since the ATH-CK5 is already discontinued, official support cannot be expected. The product warranty period has also ended, making repairs or parts replacement impossible. While it had average durability as a product of its time, aging deterioration is now unavoidable, and stable operation cannot be guaranteed.

Rationality of Design Philosophy

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The design philosophy of the ATH-CK5 was a product of compromise within the technical and price constraints of 2005. The clear lack of low-frequency response as an acoustic characteristic was the result of prioritizing cost reduction and cannot be said to be design based on scientific evidence for sound quality improvement. However, considering the technical standards and price range of the time, it cannot be said to be completely irrational. From a modern perspective, this design approach is outdated as cheaper, higher-performance products are achievable.

Advice

While the ATH-CK5 has certain significance as a historical product, we cannot recommend purchasing it as of 2025. With an equivalent budget, choosing modern products such as the 7Hz Salnotes Zero, Moondrop Chu II, or Truthear x Crinacle ZERO: RED can provide significantly superior acoustic performance. These products achieve frequency characteristics, low distortion rates, and high S/N ratios far exceeding the ATH-CK5 in the approximately 20 USD price range. For the purpose of improving music listening quality, selecting products designed based on modern technical standards is rational. This is not a product that can be actively recommended except for collectors who find value in the rarity of discontinued products.

(2025.7.24)