Overview

The Sony MDR-F1 is an open-back headphone released in 1997. Developed as part of Sony’s “Ear Speaker” concept at the time, it adopts a non-sealed driver structure that doesn’t enclose the ear. It features a 50mm neodymium driver and lightweight magnesium frame, with a 12-ohm low impedance design intended for driving with portable CD players. After 28 years since its release, it is now discontinued and only available on the used market.

Scientific Validity

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According to measurement data, the MDR-F1 shows significant frequency response degradation from 1-2kHz onwards. Major dips occur in the mid-high frequencies, confirming issues with lack of high-frequency brilliance. While the frequency range is specified as 10-30,000Hz, actual measurements fail to maintain flatness within ±3dB, greatly deviating from modern transparency standards (±0.5dB). The low frequencies also lack impact below 100Hz, with overall measurement performance reaching problematic levels. While detailed distortion characteristics data such as THD and S/N ratio are not publicly available, considering the 1997 technical standards, they are judged insufficient by modern criteria.

Technology Level

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For 1997, the adoption of a 50mm neodymium driver and lightweight magnesium frame was advanced. The inclusion of an impedance compensator to reduce the influence of output impedance can be evaluated as a technical consideration. However, by current standards, the 6mm thick diaphragm and basic open-back design remain standard approaches. The frequency response issues revealed by measurements indicate insufficient acoustic engineering verification during the design phase, and compared to modern high-precision simulation and measurement technologies, the technical level must be considered low.

Cost-Performance

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Current used market prices range from 100-233 USD (approximately 100-235 USD), varying greatly depending on condition and accessories. As a current product with equivalent or superior performance, the Philips SHP9500 (approximately 60 USD / 60 USD) can be cited. The SHP9500 features a superior frequency range of 12-35,000Hz, appropriate 32-ohm/101dB specifications, and a 50mm neodymium driver, surpassing the MDR-F1 in measurement performance. The cost-performance calculation yields 60 USD ÷ 147 USD (used average price) = 0.41, rounded to 0.4. Since current products exist that can achieve equivalent functionality at lower cost, the cost-performance evaluation is low.

Reliability & Support

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The MDR-F1 is a discontinued product from 28 years ago, and official support from Sony has already ended. Obtaining replacement parts is difficult, and repair support cannot be expected in case of failure. Quality variations due to individual differences in used products are also a concern. Being a product manufactured in 1997, driver performance degradation and pad material deterioration due to aging are inevitable. The situation of receiving no warranty or after-sales service compared to current products results in the lowest level evaluation for reliability and support.

Rationality of Design Philosophy

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The “Ear Speaker” concept itself was a rational approach aimed at natural sound field reproduction through open-back design. The low impedance design for ease of driving was also a practical consideration. However, actual measurement results show that the theoretical objectives were not realized, and particularly the mid-high frequency response issues indicate challenges in implementing the design philosophy. Currently, advances in acoustic simulation technology enable more precise design, and the design methods of that time had limitations due to temporal constraints. The rationality remains at an average level due to insufficient verification based on scientific measurements.

Advice

The Sony MDR-F1 cannot be recommended for purchase except for acoustic historical interest. Rather than purchasing at the current used price of approximately 147 USD, the Philips SHP9500 available for around 60 USD is significantly superior in measurement performance, durability, and support aspects. Unless you are a vintage audio enthusiast or Sony product collector, we strongly recommend choosing current open-back headphones for practical music listening purposes. Particularly for users who prioritize high-frequency sound quality, the frequency response issues are likely to prevent satisfactory results. If aiming for sound quality improvement, investing in modern products designed based on scientific measurements would be a rational decision.

(2025.8.4)