FiiO FD3 and FD3 Pro in-ear headphones largely inherited the technologies of the flagship FD5 model – first of all, the new products include a 12-mm speaker with a diaphragm made of diamond-like carbon (DLC), large for its class. The weight-to-stiffness ratio of this material, according to FiiO, has reduced distortion.
A powerful magnet is responsible for the movement of the membrane, for which a flux of 1.5 T is indicated. In its field there is a Japanese Daikoku voice coil wound with an ultra-thin copper-plated aluminum wire – this made it possible to slightly reduce the mass of the moving system without losing its efficiency.
Acoustic prisms are located at the focal point of the FiiO FD3 and FD3 Pro diaphragms – just like in the flagship FD5 model. By separating the flow from the diffuser, this system is designed to improve the phase response of the headphones. For a balanced frequency response, especially in the low-frequency range, the new items received a semi-open case with a likeness of a perforated acoustic impedance panel.
In all this, the FD3 and FD3 Pro models are indistinguishable. The only difference is that the Pro prefix means complete with an exclusive cable made of high-purity monocrystalline silver-plated copper.
These are eight insulated conductors, 19 strands in each – a total of 152 strands of two types of litz wire. The cable received adapters that allow you to connect to 2.5, 3.5 or 4.4 mm connectors – depending on the source.
In the US, the FiiO FD3 headphone cost $ 100, and the FiiO FD3PRO headphone cost $ 140.