Overview

The Kiwi Ears Cadenza II is a passive wired in-ear monitor released in Japan on February 20, 2026 [7]. This review covers the 3.5mm version without a microphone; a separate USB-C version includes a microphone. Its published design combines a 10mm titanium-coated PET diaphragm with the manufacturer-branded KARS 2.0 acoustic system, intended to produce an 8dB sub-bass lift that ends around 200Hz. A detachable 0.78mm 2-pin cable and six pairs of ear tips are included [1].

Scientific Validity

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Independent B&K 5128 measurements from Hangout.Audio and Earphones Archive show closely matched channels, an approximately 8dB rise from 500Hz to 20Hz, and a broad maximum near 3kHz [2][3]. Our approximate calculations from their public graphs give a Harman IE 2019 error standard deviation of 1.6dB and 2.0dB respectively, using each site’s 5128-adapted target, logarithmically spaced samples over 20Hz–10kHz, and removal of the mean error. These are graph-derived estimates, not statistics published by the measurers. Sample, ear-tip and measurement differences limit the precision of the comparison. The response is reasonably close overall, but the 4–8kHz region is subdued and a deeper dip occurs near 10kHz; the peak above 10kHz also varies between measurements.

Kiwi Ears specifies THD below 1% at 1kHz without a sound-pressure or input-level condition [1]. No independent distortion or passive-isolation measurements were found. The response and channel matching support a moderately positive assessment, but do not establish low distortion or strong isolation. The reviewed version has no ANC or internal signal processing.

Technology Level

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Kiwi Ears combines its own KARS 2.0 acoustic-path design with a newly developed titanium-coated PET diaphragm [1]. The internal labyrinth controls rear pressure and airflow [7], giving the product a specific acoustic implementation. Nevertheless, passive acoustic chambers and diaphragm coatings are established techniques, and this version has no electronic or software integration. It represents a refinement of a mature acoustic platform rather than a substantial advance in overall technology.

Cost-Performance

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This site evaluates based solely on functionality and measured performance values, without considering driver types or configurations. The Cadenza II’s current regular price is 49.99 USD for the 3.5mm version [1]. The lowest-priced identified candidate retained for a provisional comparison is the 7Hz x Crinacle Zero:2, 3.5mm without a microphone, at 24.99 USD [4]. Both provide passive 3.5mm playback, replaceable 0.78mm 2-pin cables and supplied ear tips, without DSP/EQ, wireless connectivity or ANC. No additional accessory is needed with the same 3.5mm source.

CP = 24.99 USD ÷ 49.99 USD = 0.4999 → 0.5

These are direct-import USD listings, not confirmed US warehouse offers. Linsoul advertises standard shipping free to most countries; destination taxes and address-dependent charges may be additional [4]. The Japanese market ratio rounds differently, so the same USD comparison is used for both language editions; the Japanese listing retains the actual domestic Cadenza II price [6][7][8].

Using the calculation above, three Hangout.Audio Zero:2 samples have Harman-error STDs of approximately 1.7, 2.0 and 1.7dB, compared with Cadenza II’s 1.6dB there and 2.0dB at Earphones Archive [2][3]. Their central values and observed ranges are close, supporting provisional equivalence rather than a claim that every Zero:2 sample is better. In particular, its second sample deviates more than Cadenza II on the same rig. Zero:2 has approximately 2–3dB more bass, a shallower dip near 10kHz, and a similar upper-treble peak. Its channels generally track closely, though the third sample has a local difference of approximately 2dB near 150Hz. Cheaper GATE has a lower average Harman error but larger channel differences in the Hangout sample; Salnotes Zero and CHU II have larger peaks near 12kHz. These differences prevent using their lower prices as clear equivalents [2].

ASR’s Zero:2 measurements on a GRAS 45CA show THD below approximately 0.1% over 20Hz–10kHz at 94 and 104dBSPL and below 0.3% at 114dBSPL [5]. The 94dB trace is partly limited by measurement noise. This supports the candidate’s low distortion, but cannot establish a measured advantage over Cadenza II’s unspecified-level manufacturer limit. Isolation equivalence also remains unverified. The provisional comparison therefore depends on the observed frequency-response range and available distortion evidence; a controlled same-condition comparison of further units, distortion and isolation could change it.

Reliability & Support

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Kiwi Ears provides a one-year warranty on the earphones and three months on the cable [1]. The passive construction avoids battery ageing, and the detachable 0.78mm 2-pin cable lets users replace a commonly stressed part without manufacturer service. Warranty requests are accepted by email or the manufacturer’s website. A worldwide authorized repair network, statistical failure rates and long-term repair availability could not be established. The simple construction is a practical strength, balanced by the short warranty; the unknown support and failure-rate information does not establish poor reliability.

Rationality of Design Philosophy

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The design uses the acoustic pathway to shape the bass response without requiring external equalization. Matching that pathway to the diaphragm is a functional use of a proprietary mechanism, and the replaceable cable serves everyday maintenance [1][7]. This is a rational purpose for a dedicated earphone. The manufacturer also emphasizes material purity and subjective detail or tonal descriptions; these do not establish a wholly measurement-led design philosophy. No additional audible benefit is assigned to the cable’s copper purity or the faceplate’s material grade. The overall approach is moderately positive for its purposeful acoustic design, without assuming that elaborate materials or a newer model automatically improve fidelity.

Advice

The Cadenza II suits buyers seeking a passive wired IEM with elevated sub-bass, closely matched channels and a detachable cable. Its subdued 4–8kHz response is worth considering alongside fit and sealing. Independent distortion and isolation evidence remains limited. Zero:2 offers a lower-cost option with similar overall response and additional distortion measurements, subject to the sample and isolation limitations discussed above [2][4][5]. Choose the USB-C version separately if a microphone or direct digital connection is required; its electronics are outside this review.

References

[1] Kiwi Ears - Cadenza II Official Product Page - https://kiwiears.com/products/kiwi-ears-cadenza-ii - accessed 2026-09-26; 3.5mm no-microphone variant, regular price, specifications and warranty

[2] Hangout.Audio / In-Ear Fidelity - IEM Comparison Graphs - https://graph.hangout.audio/iem/5128/?share=Harman_IE_2019_(B%2526K_5128)_Target,Zero_Salnotes,Cadenza_2,Gate,Chu_2,EDX_Pro,Zero2_S1,Zero2_S2,Zero2_S3 - accessed 2026-09-26; B&K 5128, rig-adapted Harman IE 2019, channel and sample comparisons

[3] Earphones Archive - Cadenza II Frequency Response - https://earphonesarchive.squig.link/?share=Harman_IE_2019for_5128_Target,Kiwi_Ears_Cadenza_II(short_tip) - accessed 2026-09-26; B&K 5128, short tips, left/right curves and rig-adapted Harman target

[4] Linsoul - 7Hz x Crinacle Zero:2 - https://www.linsoul.com/products/7hz-x-crinacle-zero-2 - accessed 2026-09-26; authorized distributor, 3.5mm without microphone, regular 24.99 USD, specifications and shipping conditions

[5] Audio Science Review - 7Hz x Crinacle Zero:2 IEM Review (amirm) - https://www.audiosciencereview.com/forum/index.php?threads/7hz-x-crinacle-zero-2-iem-review.50534/ - December 18, 2023, accessed 2026-09-26; GRAS 45CA, supplied red tips, THD graphs at 94/104/114dBSPL

[6] Linsoul Japan [JA] - 7Hz x Crinacle Zero:2 - https://linsoul.jp/products/7hz-x-crinacle-zero-2 - accessed 2026-09-26; 3.5mm without microphone, current Japanese-market price, direct import

[7] Yodobashi Camera [JA] - Cadenza II Grey KWI050 - https://www.yodobashi.com/product/100000001009702015/ - accessed 2026-09-26; Japanese release date, specifications and current tax-inclusive domestic price, limited stock and free delivery

[8] Linsoul Japan - Shipping Policy - https://linsoul.jp/pages/shipping - accessed 2026-09-26; Japanese standard-shipping conditions and possible import fees

(2026.9.26)