Overview

The Audio-Technica ATH-CK100 was the brand’s flagship triple balanced-armature in-ear monitor with a 2-way 3-driver layout (two drivers for mids/highs, one for bass) in compact titanium shells. It launched at an MSRP of 649.99 USD with rated 20 Hz–18 kHz bandwidth, 113 dB/mW sensitivity, and 23 Ω impedance; at release it was advertised as the “world’s smallest” triple-driver IEM [1][2].

Scientific Validity

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Published specs top out at 18 kHz rather than 20 kHz [1]. Sensitivity (113 dB/mW) and impedance (23 Ω) are adequate for portable sources [1]. Because comprehensive third-party lab measurements for the CK100 itself (e.g., THD, channel balance, crosstalk) are not publicly available, we follow the rule to assign 0.5 when full measurement coverage is unknown [1][2].

Technology Level

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For its time, the CK100’s triple-BA execution, miniaturized packaging, and titanium housings were competent, though subsequent low-cost IEMs have matched or surpassed such engineering at far lower prices.

Cost-Performance

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Comparator: KZ EDC Pro — chosen strictly on measurement grounds and lowest price.

• Measured data (RAA): professional report lists average impedance ~27 Ω and the voltage for 90 dB SPL = −39.1 dBV; this corresponds to ≈113.4 dB SPL/mW, i.e., not inferior to the CK100’s 113 dB/mW spec [4]. The RAA report includes full-band FR plots.
• Official price: 14.00 USD on the KZ official store [3].

Using USD for parity with the CK100 MSRP, the value ratio is ≈0.022, which maps to 0.0 on our scale. CK100’s cost-performance is therefore extremely poor relative to the cheapest measurement-non-inferior alternative.

Reliability & Support

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Audio-Technica U.S. warranty coverage is established; products must be delivered to service prepaid by the end user. Validated warranty repairs cover return shipping, parts, and labor [5]. As a discontinued model, parts availability is uncertain despite strong brand-level support.

Rationality of Design Philosophy

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The CK100 reflects rational, audio-specific engineering (multi-BA with rigid housings), but its premium pricing was not tied to measurement-verified advantages that remain competitive today.

Advice

Not recommended on value grounds. If you want baseline value with measurement backing, KZ EDC Pro is the lowest-price, non-inferior comparator used here [3][4]. Seek current IEMs with transparent, third-party measurements for better objective performance per dollar.

References

[1] AV Watch – CK100 launch article (JP; specs/price): https://av.watch.impress.co.jp/docs/20081016/autech1.htm
[2] The Headphone List – ATH-CK100 (MSRP 649.99 USD): https://theheadphonelist.com/audio-technica-ath-ck100/
[3] KZ Official Store – EDC Pro product page (price 14.00 USD): https://www.kzheadphones.com/products/kz-edc-pro-earbuds-dynamic-in-earphones
[4] Reference Audio Analyzer – KZ EDC Pro professional measurement report: https://reference-audio-analyzer.pro/report/hp/kz-edc-pro.php
[5] Audio-Technica US – Two-Year Limited End-User Warranty (deliver prepaid): https://www.audio-technica.com/en-us/support/us-two-year-limited-end-user-warranty

(2025.9.5)