Overview

The Sony WF-1000XM4, released in 2021, is a flagship true wireless earphone from Sony. It features industry-leading noise cancellation powered by the proprietary V1 processor, high-quality audio transmission with LDAC support, and IPX4 water resistance. Initially priced around 207 USD (approx. 280 USD), its price has now dropped to around 180 USD, partly due to the release of its successor. Although it has been on the market for some time, its powerful noise-canceling performance continues to be highly regarded and supported by many users.

Scientific Validity

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While its nominal frequency response range is 20Hz-40kHz, independent measurements confirm intentional sound tuning, particularly a significant boost of over +6dB in the low frequencies. This is a major deviation from the standard for high-fidelity reproduction (20Hz-20kHz ±3.0dB) and is considered problematic from a scientific fidelity perspective. Total Harmonic Distortion (THD) is good at normal listening volumes (90dBA), but it increases at higher volumes (100dBA and above), especially in the low-frequency range, leading to sound quality degradation. On the other hand, the noise-canceling performance is extremely effective, significantly reducing ambient noise, particularly in the mid-to-low frequencies. This sound isolation is scientifically beneficial for improving the clarity of the sound reaching the eardrum, but the evaluation is limited due to issues in the fundamental playback fidelity of the drivers.

Technology Level

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The design, which integrates the V1 processor for digital signal processing and an analog amplifier onto a single chip, is technically excellent, achieving a high signal-to-noise ratio in a compact body. Support for the LDAC codec enables the transmission of Hi-Res Audio equivalent data when connected to a compatible Android device. The use of a liquid crystal polymer diaphragm in its small 6mm drivers to claim high-frequency reproduction up to 40kHz is also commendable. However, these technologies are no longer particularly novel, given the time since release, and cannot be described as revolutionary by today’s highest industry standards. The refined implementation that brings existing technologies together at a high level is praiseworthy, but it represents the state of the art as of 2021.

Cost-Performance

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Compared to its current market price of around 180 USD, there are more affordable products with equivalent or superior functionality. For example, the Anker Soundcore Liberty 4 NC offers LDAC codec support, powerful active noise cancellation comparable to this product, IPX4 water resistance, and longer battery life, all while being available for about 100 USD. The calculation is: 100 USD ÷ 180 USD = 0.55, resulting in a score of 0.5. The Soundcore Liberty 4 NC has no inferior elements in terms of core user experience or measurable performance metrics, offering similar value at nearly half the price. This product does not demonstrate a significant advantage to justify the price difference.

Reliability & Support

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As a major manufacturer, Sony offers high reliability, providing a one-year product warranty and an established repair support system both domestically and internationally. While specific product failure rates are not public, the earphones are considered to have standard durability for the true wireless category. The IPX4 water resistance rating ensures they can withstand daily sweat and light rain, but they are not fully waterproof. Firmware updates are also provided, offering bug fixes and feature enhancements. While it may not be the best warranty in the industry, the expectation of stable support is a reassuring factor.

Rationality of Design Philosophy

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The integration of multiple functions—such as noise cancellation, ambient sound mode, and high-quality codec support—into a compact, low-power design centered around the V1 processor is rational. However, this design prioritizes a “consumer-friendly” sound signature with an intentional bass boost over the scientific principle of “faithful reproduction of the master recording.” This direction deviates from the pursuit of pure audio performance. Furthermore, with more affordable alternatives like the Anker Soundcore Liberty 4 NC now offering equivalent functionality, the necessity of this product as a dedicated audio device has diminished. While the advanced functional integration is commendable, its rationality is questionable in terms of sound signature and cost structure.

Advice

While the noise-canceling performance of the Sony WF-1000XM4 remains top-tier, better value alternatives exist when considering the overall package. Unless you have a specific preference for the brand, the Anker Soundcore Liberty 4 NC is strongly recommended at about half the price. It offers comparable LDAC support and ANC performance, making it a far superior choice in terms of cost-performance. Even for those who prioritize the Sony brand, there are few compelling reasons to choose this particular model today. If you have already purchased it, it is crucial to use it with an LDAC-compatible Android device to maximize its performance. When considering a future upgrade, it is advisable to calmly assess the balance between objective performance and price, rather than relying on brand image alone.

(2025.7.22)