High-Quality Sound With High-Quality Dynamic Driver FiiO has crafted the 10mm dynamic driver of the FD11 with the same materials as they have designed for the FH15 and FF5 IEMs. FD11 gets a serious boost in its sound capabilities with this premium dynamic driver unit. It features a dual-cavity design and a carbon-based diaphragm material. It grants the pair a highly-responsive sound that has a smooth timbre and minimal distortion. Asymmetric External & Internal Magnetic Circuits The new FD11 employs second-generation asymmetric internal and external magnetic circuit systems. Through the use of finite element simulation, the FD11’s dual magnetic circuit design has been optimized to generate a stronger magnetic field compared to a typical dynamic driver’s single internal or single external magnetic circuit system. This results in a higher magnetic field density, allowing the diaphragm to be more powerfully driven for a more “robust” sound with better transient response. The FD11 utilizes N52 neodymium magnets that give the earphone its 111 dB/mW@1kHz sensitivity. In simulation tests compared to the typical dynamic driver’s single external magnetic circuit, the FD11’s dual asymmetric internal and external magnetic circuits not only feature higher magnetic density but also features a wider magnetic field. This means that the FD11 handles highly dynamic audio with ease, and with lower distortion than what is typical in its class. The rear of the FD11’s dynamic driver features a unique dual-layer cavity, allowing the development team to install damping control systems in both the inner and outer chambers to precisely control air flow – resulting in reducing distortion and allowing the diaphragm to move more freely without breakup. This results in both more detailed treble and especially more robust and more resolving bass, with the driver faithfully reproducing low-frequency details with astonishing speed. Exquisite Design, Comfortable Fit FiiO FD11 is designed with the ultimate craftsmanship from the brand. They features high-quality zinc alloy material shells that are decanted into the shape and then polished and electroplated to treat the users with an exquisitely finished product. It has a Conch-like shape. The FD11 has an ergonomic shape that promises a comfortable wearing experience for the users. C-Shaped Acoustic Flute FiiO has also implemented a C-shaped acoustic flute within the ear shell of the FD11. It serves to notably enhance sound quality – this feature especially focusing on the bass. When air moves through the internals of the FD11, the C-shaped acoustic flute helps to increase the viscosity of the air and reduces the resonance frequency, which helps to improve both mid-bass and sub-bass quality. It means you can now clearly feel the cohesiveness and power behind the sound of drums being beat. High-Quality Stock Cable FiiO FD11 comes with a high-quality stock cable. It’s a high-purity 4-strand oxygen-free copper wire with 120 wire cores on each strand. The high-quality oxygen-free copper material greatly enhances the performance of the pair by providing smooth signal transmission and low internal resistance.