Flagship sound Three years ago, the FH9 was launched, as FIIO’s first high-end flagship hybrid earphone. With its energetic dynamics, wide soundstage, and pleasant sound quality, it was enthusiastically received by HiFi users worldwide upon release. It gradually became known among audiophiles as a great example of “balanced earphones,” far exceeding our expectations in popularity. It is still a competitive set of earphones even in today’s market. The new FIIO FH19 from FIIO is a significant upgrade, incorporating much user feedback. It retains the signature sound and flagship-grade craftsmanship of the FH9, and is also co-developed with Tokyo Onkyo Ltd. in Japan and Knowles in the USA. It features a truly high-end acoustic design, with richer and fuller midrange and more robust yet flexible bass. Additionally, the fit has been redesigned and optimized based on the characteristics of the human ear, allowing you to experience truly flagship-level comfort. Two dynamic six BA driver configuration The new FIIO FH19 features a flagship-worthy dual dynamic and six-balanced armature driver configuration. Handling the bass is an all-new push-pull dual dynamic driver unit co-developed with Tokyo Onkyo Ltd. in Japan. This driver features greatly enhanced low-frequency extension, cohesion, and speed. The mid-to-high frequencies are handled by specially customized Knowles-enhanced midrange balanced armature drivers, which achieve greater sound energy density for rich and delicate vocals that are wonderfully musical without sacrificing detail. Push-pull dual dynamic driver unit FIIO, in collaboration with Tokyo Onkyo Co. Ltd., has developed a push-pull dual dynamic driver unit for the FH19, based on push-pull technology used in high-end audio. This technology employs two 13.7mm high-magnetic dynamic drivers with PU+DLC composite diaphragms, arranged in an opposing configuration. When the diaphragms move back and forth, the overall movement direction of the two dynamic drivers remains consistent, ensuring phase consistency. This effectively doubles the driving force, and the diaphragms can provide air damping to each other. This makes the dynamic drivers exhibit more stable movement and fully suppress any residual sound after the audio signal stops. Compared to typical dynamic drivers, push-pull dual dynamic drivers require only half the amplitude to achieve the target sound pressure level. This results in smaller diaphragm displacement, significantly improving linear driving performance and further reducing intermodulation distortion, allowing the driver unit to deliver cleaner sound. Custom Knowles - Enhanced mids BAs The FIIO FH19 uses six Knowles balanced armature drivers as its mid and high-frequency sound units. In order to achieve even higher levels of vocal sound quality, FIIO collaborated with Knowles to create a custom mid-frequency-enhanced balanced armature driver. By adding acoustic vents to the rear cavity of the driver, the mid-frequency driver gains more sound energy compared to typical mid-frequency drivers. This further unlocks the inherent advantages of the mid-frequency driver, resulting in rich and mellow vocals that are hauntingly realistic, as if the singer was right next to you. Semi-open design The semi-open design has been highly praised in the FIIO FH9, FH7S, FH5S, and FD5. In the FH19, this proven semi-open design is once again utilized and has been specially tuned to combine with FIIO’s front and rear cavity balanced pressure relief technology – resulting in a more natural and relaxed sound, with a wide soundstage. This design efficiently balances the internal air pressure, eliminating the feeling of pressure on the eardrum which also helps to protect your hearing. Enjoy listening for long periods without fatigue. Mid-frequency notch filter The FH19 features a variety of different drivers and acoustic design principles. Scientifically tuning each part so that they work in a harmonious whole is the essence of high-level tuning. To achieve this, the FIIO development team has specially designed a “mid-frequency notch filter” for the FH19 hybrid earphones. Further upgraded mids Testing shows that the mid-frequency notch filter device of the FH19 not only allows the BA drivers to retain their high resolution and clarity but also enhances the mid-frequency sound pressure level. This makes the vocals denser and fuller while also ensuring a smooth transition between the dynamic driver and the mid-frequency BA driver. Eliminating sibilance The FH19’s mid-frequency notch filter effectively filters out the high-frequency 8kHz peak produced by the mid-frequency drivers. This reduces the overlap between the sound produced by the mid-frequency and high-frequency drivers, thus eliminating sibilance while still ensuring high sound quality. Easily gained highs The mid-frequency notch filter can also advance the crossover point of the balanced armature ...