Overview

The KZ ASX represents KZ’s flagship attempt at a premium in-ear monitor, featuring an impressive-sounding 20 balanced armature drivers (10 per side) in a CNC-machined aluminum housing. Priced at approximately 179 USD, the ASX positions itself as a high-end offering with complex driver arrays including dedicated BA22955s drivers for low frequencies, 29689s for midrange, and multiple 30017 and 31736 drivers handling high frequencies. The earphones feature 3D-printed acoustic chambers, silver-plated cables, and detachable QDC 2-pin connectors. However, beneath the impressive specifications lies a product that prioritizes marketing appeal over measured performance improvements.

Scientific Validity

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Third-party frequency response measurements from Crinacle’s database [2] show significant deviations from target curves, with problematic bass response and treble presentation. Independent measurements indicate frequency response deviations exceeding ±3dB across critical midrange frequencies, placing performance at problematic levels according to established criteria. Reviews consistently report measurable issues including excessive bass boost causing “wobbly and boomy” response and treble that appears “rolled off” despite forward positioning [3]. The manufacturer specifications claim 20Hz-40kHz response with 106dB/mW sensitivity and 20Ω impedance [1]. Manufacturer specifications indicate low distortion claims for the balanced armature drivers, though comprehensive THD, IMD, and distortion measurements remain unavailable from independent third-party sources for verification. Third-party verification shows actual performance falls short of transparent-level targets, requiring conservative scoring adjustment due to reliance on non-manufacturer measurement sources. The 20-driver configuration demonstrates no measurable performance advantages over properly tuned alternatives with fewer drivers.

Technology Level

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The ASX employs conventional multi-balanced armature technology with 4-way crossover implementation and 3D-printed acoustic chambers for driver isolation. The CNC-machined aluminum construction and silver-plated cabling represent established manufacturing approaches with competent execution of multi-driver principles. The underlying technology lacks meaningful innovation beyond mature BA driver technology, relying on driver count multiplication without corresponding measurable performance improvements. The approach reflects conventional engineering without proprietary patents or unique technical contributions. Technology integration remains analog/mechanical without modern digital signal processing or software features. The manufacturing quality demonstrates technical competence, though the approach offers limited differentiation from competing multi-driver implementations available at lower price points.

Cost-Performance

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CP = 40 USD ÷ 179 USD = 0.2

The KZ ZS10 Pro at approximately 40 USD provides equivalent-or-better functionality. Equipped with detachable cables, and frequency response measurements show superior tuning execution with more neutral response characteristics and lower frequency response deviation compared to the ASX’s problematic bass boost and treble issues documented in third-party measurements [4]. The ZS10 Pro demonstrates equivalent-or-better measured performance in frequency response accuracy, driver coherence, and overall tuning. The ZS10 Pro achieves equivalent audio reproduction functions while maintaining measurably better frequency response linearity. Despite costing over four times as much, the ASX fails to demonstrate measurable performance advantages that justify the significant price premium over this established comparison target.

Reliability & Support

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KZ provides a standard 1-year warranty period, which falls below the industry average of 2 years. The complex 20-driver configuration inherently increases potential failure points compared to simpler designs, presenting reliability concerns. The warranty system requires customers to bear shipping costs for warranty claims, with repair services available at 75 EUR per hour for out-of-warranty units. Support infrastructure operates primarily through dealer networks rather than direct manufacturer support. While KZ has established global distribution, the company lacks the extensive support infrastructure of larger manufacturers. The multi-driver design complexity, combined with shorter warranty periods and customer-paid shipping for claims, places this product below average in the reliability and support category.

Rationality of Design Philosophy

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The design philosophy demonstrates mixed approaches to scientific rationality and market positioning. While the 20-driver configuration lacks clear measurable justification for improved performance, the use of CNC-machined aluminum construction, 3D-printed acoustic chambers, and dedicated frequency-specific BA drivers shows some engineering effort toward performance optimization [1]. The approach prioritizes driver count multiplication without corresponding advances in measured performance parameters, representing questionable cost allocation toward marketing appeal rather than functional improvements. However, the adoption of detachable cables, quality construction materials, and structured driver arrays indicates some consideration for user functionality and long-term usability. The design philosophy conflicts with evidence-based approaches that achieve superior results through optimized tuning, though the technical implementation shows competent application of established multi-driver principles without meaningful innovation.

Advice

The KZ ASX serves as an example of ambitious multi-driver implementation with mixed results in execution. At 179 USD, significantly better-performing alternatives exist at approximately one-quarter the cost, making this product poorly competitive for consumers seeking value-oriented audio solutions. The KZ ZS10 Pro at 40 USD provides superior measured frequency response accuracy with more coherent driver integration, demonstrating that driver count multiplication does not guarantee performance improvements. Potential purchasers should prioritize products with verified third-party measurements showing transparent-level performance rather than impressive driver counts. For those specifically interested in KZ products, consider their simpler, better-tuned models that focus on optimization rather than complexity. The ASX may appeal to consumers valuing premium aluminum construction, detachable cables, and multi-driver engineering, though the measured performance does not fully justify the price premium over more affordable alternatives.

References

[1] KZ ASX Official Product Page - https://kz-audio.com/kz-asx.html - Accessed 2025-09-23 - Manufacturer specifications: 20Ω impedance, 106dB/mW sensitivity, 20-40kHz frequency range

[2] Crinacle In-Ear Fidelity - KZ ASX Measurements - https://crinacle.com/graphs/iems/kz-asx/ - Updated May 18, 2021 - Third-party frequency response measurements

[3] AudioFool Reviews - KZ ASX Review - https://audiofool.reviews/2020/10/28/kz-asx/ - Accessed 2025-09-23 - Independent assessment of sound signature and performance characteristics

[4] KZ ZS10 Pro Crinacle Measurements - https://crinacle.com/graphs/iems/kz-zs10-pro/ - Accessed 2025-09-23 - Third-party frequency response measurements showing superior tuning execution; KZ ZS10 Pro specifications - https://kz-audio.com/kz-zs10-pro.html - Hybrid driver configuration specifications

[5] KZ Warranty and Repair - https://kzaudio.nl/pages/warranty-and-repair - Accessed 2025-09-23 - Official warranty terms: 1-year period, customer bears shipping for warranty claims, 75 EUR/hour repair tariff

(2025.9.23)