The FiiO development team created the FD11 and FH11 as a part of a new “Bionic Conch” series of products that aims to punch above its price class in both aesthetics and sound. High-end techniques were used to create the unique sense of flow that the FD11 and FH11 radiate from their appearance, and innovative features such as the C-shaped acoustic flute elevate the sound quality to the next level by giving a truly “cohesive unified” sound.
For the FD11’s 10mm carbon-based dynamic driver, the development team chose to use the same materials as found in the high-end FH15 and FF5 IEMs, giving the FD11 a serious boost to its sound capabilities.
The carbon-based material is ideal for the diaphragm – being lighter than aluminum, beryllium, and other materials while having a tensile strength nine times that of steel. The carbon-based diaphragm results in a highly-responsive and detailed driver that can easily handle quick transients with minimal distortion thanks to minimal breakup during driver movement.
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 111dB/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 feature 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.
In addition to the new conch-like shape of the FH11, the C-shaped acoustic flute within the FD11 also serves to notably enhance sound quality – this feature specifically focuses on the bass. When air moves through the internals of the FD11, the C-shaped acoustic flute helps to increase the viscosity of that air and reduces the resonance frequency, which helps to improve both mid-bass and sub-bass quality. What this means is now you can clearly feel the cohesiveness and power behind the sound of drums beating.