The FiiO FD3 Pro is a single dynamic driver in-ear monitor that brings flagship-grade technology from the FD line down to a more accessible price point. At its heart lies a newly designed 12mm driver with a Diamond-Like Carbon (DLC) diaphragm — a material prized for its exceptional rigidity and light weight, which together deliver excellent transient response and vanishingly low distortion.
The driver is paired with a powerful 1.5 Tesla magnetic circuit and an ultra-fine copper-clad aluminium Daikoku voice coil, providing the authority and control needed for dynamic, engaging sound. FiiO's acoustic prism technology — previously exclusive to the flagship FD5 — eliminates high-frequency standing waves, improves sound wave diffusion, and resolves time-delay issues within the cavity, contributing to the FD3 Pro's remarkably open and spacious presentation.
A semi-open acoustic design further enhances naturalness and protects hearing by balancing air pressure within the earphone, reducing fatigue during extended listening sessions. The earphones feature interchangeable sound tubes: the black tube (larger bore) emphasises treble detail, while the red tube (smaller bore) brings more weight to the bass — allowing listeners to tailor the sound signature to their preference.
The shells are crafted from aluminium-magnesium alloy using five-axis CNC machining and hand polishing, finished with a 2.5D film-coated glass faceplate for a premium, transparent look. MMCX connectors with an expanded design make cable swapping straightforward.
The FD3 Pro comes supplied with an exclusive cable made from high-purity monocrystalline silver-plated copper, featuring 8 strands of 19 wires braided in Litz Type 2 configuration for a total of 152 individual conductors. Interchangeable audio plugs allow free switching between 2.5mm balanced, 3.5mm single-ended, and 4.4mm balanced connections, making the FD3 Pro at home with any portable source. The earphones are Hi-Res Audio certified.