Overview

The KZ PRX is a 4th generation planar magnetic in-ear monitor released by KZ Audio in late 2024. It features a 13.2mm silver-plated planar driver with 14 N52 double-sided magnets, representing significant improvements over the previous PR series. At 40 USD, it delivers technical performance comparable to competing higher-priced products, establishing itself as a notable planar IEM. This product demonstrates KZ’s technical maturity with technological improvements applied to their planar product lineup.

Scientific Validity

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The KZ PRX achieves good measurement performance levels for a planar IEM. The nominal frequency response covers 20Hz-40kHz with 15Ω impedance and 94dB sensitivity, allowing proper amplification. Third-party measurements show frequency response within ±2dB across the 20Hz-20kHz range, confirming good responsiveness for a planar design. However, specific values for detailed harmonic distortion and S/N ratio are not publicly available, lacking clear measurement data like the competing Letshuoer S12’s THD+N<0.2%. Some planar-specific metallic resonance remains, preventing achievement of completely transparent levels, but measurable improvements are demonstrated, realizing scientific validity.

Technology Level

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As 4th generation planar technology, the 13.2mm silver-plated vacuum-deposited diaphragm with 14 N52 magnets in a double-sided drive configuration is technically competitive. Compared to competing products like the Letshuoer S12’s 14.8mm driver or TinHiFi P1 Max’s 14.2mm driver, the driver size is appropriate and magnet placement efficient. Silver-plated cables and 0.75mm 2-pin connectors show consideration for signal transmission. However, these technologies are combinations of established methods in the existing planar IEM field, with limited revolutionary proprietary technology. This can be evaluated as a rational design emphasizing the balance between manufacturing cost and performance, though it doesn’t reach industry-leading technical levels.

Cost-Performance

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The KZ PRX is available for 40 USD, making it an inexpensive option among planar driver IEMs. However, the evaluation must compare it against all IEMs with equivalent functionality and performance, regardless of driver type. For example, dynamic driver IEMs like the Truthear HOLA (approx. 20 USD) achieve an equally flat or flatter frequency response and low distortion at a lower price. The cost-performance is calculated as “20 USD ÷ 40 USD = 0.5”. Therefore, unless one specifically values the experience of planar technology at a low price, better alternatives exist in terms of pure performance-to-price ratio.

Reliability & Support

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KZ holds an established position as a Chinese audio brand with wide distribution through global sales networks. Multiple authorized sales channels including Amazon, Linsoul, and AliExpress ensure good availability. Standard product warranties are provided, but the comprehensiveness of after-sales support is limited compared to premium brands. Quality consistency across KZ’s product lineup has improved, and the PRX can be expected to have similar reliability. However, long-term support such as firmware updates is not applicable, covering only physical product warranties. This can be evaluated as industry-average reliability and support systems.

Rationality of Design Philosophy

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The KZ PRX’s design philosophy is scientifically extremely rational. By implementing planar magnetic technology at the 40 USD price point, it promotes the popularization of audio technology. The design that eliminates unnecessary decoration and expensive materials while concentrating resources on parts directly contributing to acoustic performance represents a scientific approach itself. The development stance of adopting only technologies that contribute to measurable performance improvements while emphasizing objective technical specifications over subjective elements deserves high evaluation. By providing planar technology’s characteristic high-speed response and distortion characteristics at lower prices than before, it simultaneously realizes technological innovation and price optimization in the audio industry, making it an extremely rational product.

Advice

The KZ PRX is an attractive option for users wanting to experience planar magnetic technology for the first time. At 40 USD, users can experience the high-speed transient response and resolution characteristic of planar IEMs. However, sufficient power is required for proper driving, and using DAC amplifiers or dongle DACs with 150mW or higher output is recommended. Direct smartphone connection may not reveal the product’s true performance potential. If pure cost-performance is the priority, one should also consider dynamic driver IEMs that offer superior measured performance at a lower price. The planar-specific metallic resonance noted in this model may be a concern for some listeners, so checking other reviews is advisable.

(2025.7.27)