Overview

The KSC75 combines an open-back ear-clip design with 2 µm titanium-coated diaphragms (spec: 15–25,000 Hz, 60 Ω, 101 dB, THD <0.2%). It favors situational awareness and comfort in casual listening scenarios.

Scientific Validity

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Independent data (RTings) show Low-Frequency Extension of 62.59 Hz and Low-Bass error of −9.76 dB, evidencing insufficient sub-100 Hz output. Weighted THD rises with level (0.219% @90 dB; 0.715% @100 dB). Being open-back, passive isolation is negligible. Scoring relies primarily on this third-party data; manufacturer bandwidth is contextual only.

Technology Level

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A conventional dynamic platform modestly enhanced by a 2 µm titanium coating. The minimalist build is cost-effective but omits modern conveniences like detachable cabling.

Cost-Performance

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Typical US street price example: 19.99 USD (Amazon). As the cheapest equal-or-better comparator, Moondrop Chu II (wired IEM with credible near-target FR assessments and isolation) is 18.99 USD in the US market; the resulting ratio supports a maximum CP score within our rubric.

Reliability & Support

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Koss provides a Limited Lifetime Warranty. For U.S. service, the stated handling/return shipping is 9 USD per stereophone. The fixed cable is a practical weak point, and the lightweight plastic build is not intended for abuse.

Rationality of Design Philosophy

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Prioritizing open staging and midrange clarity over deep bass is internally consistent for the price. Material and mechanical simplicity channel cost toward audible performance rather than cosmetic features.

Advice

Buy it for clear mids, airy presentation, and awareness of surroundings. Skip it if you need sub-bass heft, isolation, or a detachable cable. Fit and foam condition materially affect tonality—take a minute to dial in clip position.

References

• RTings — Koss KSC75 Review, https://www.rtings.com/headphones/reviews/koss/ksc75 (LFE 62.59 Hz; Low-Bass −9.76 dB; Weighted THD 0.219%/0.715%)
• Koss — KSC75 Ear Clip (official page), https://koss.com/products/ksc75
• Koss — Warranty Repair (policy & 9 USD U.S. handling/return shipping), https://koss.com/pages/warranty-repair
• Amazon.com — KSC75 price example, https://www.amazon.com/Koss-KSC75-Portable-Stereophone-Headphones/dp/B0006B486K
• SoundGuys — Moondrop Chu II review (price & FR assessment context), https://www.soundguys.com/moondrop-chu-ii-review-104977/

(2025.8.16)