https://www.fiio.com/fa7
https://penonaudio.com/fiio-fa7.html

Fiio FA7 Quad Balanced Armature Driver MMCX HiFi Audiophile in-Ear Earphones
Description
The industry's leading 3D printing technology breaks through the traditional process geometry
FA7 is the first earphone that USES 3D printing technology to realize mass production in the four-unit dynamic earphone. FiiO has deep cooperation with HIM3D, and adopts advanced industry-level cabinet 3D printing equipment and DLP printing technology, with printing accuracy up to 25µm. Each pair of ear shells are made by 60 minutes, thousands of DLP projections, and thousands of repeated lifting and printing movements. Through precise digital modeling, each pair of earphones can achieve accurate consistency. The integrated seamless cavity reduces the resonance effect of the cavity escort for good sound
European Union IIA skin-friendly resin, build a golden god
Using the European Union IIA medical certification of ear medical materials - Germany imported high transparency resin, feel comfortable when skin friendly resin is in contact with skin, no bacteria breeding; the earphone body is durable and does not change color, with high stability, so that the body presents a crystal clear effect.
The structural design is highly restored and the imagination will be carried out to the end
Compared with the traditional process, the advantage of 3D printing technology is that you can build what you want, without the constraints of the process, which is not limited by the manufacturing process, and fully presents a more ear-touching comfortable wearing model and fine acoustic cavity structure.
Knowles 4 balanced armature unit, release 4 times power
Select Knowles 4 balanced armature unit combination scheme, the low frequency unit adopts CI-22922, which is far beyond the diaphragm area of other balanced armature units. It can provide low distortion, fast and abundant low frequency. The classical ED-29689 intermediate frequency unit makes the human voice more full and sweet, which can be heard for a long time. Specially designed for FA7, SWFK-31736 composite high frequency unit can greatly enhance the high frequency density and ultra-high frequency extension, and bring you the natural and clear sound.
The quarter frequency exquisite processing, appears the shock timbre
Combined with 3D printing technology, FA7 adopts the standard independent four-frequency design, accurately calculates the connection of playback frequency of each unit, and reasonably distributes low, medium, high and ultra-high frequency bands. Low frequency power surging, intermediate frequency human voice junction image clear, high frequency and ultra-high frequency resolution superior not harsh; partial popular tuning, take into account the sizes of the system, longitudinal sound field depth is appropriate, the effect of human voice in head is very small, wearing for a long time is not tired of hearing.
Four balanced armature VS four driver hybrid
Hybrid earphones and pure balanced armature earphones are just like Benz and BMW in cars. Four Hybrid units earphone FH5’s expressive force is as gentleman, honest, soft and comfortable as Benz; The FA7 of pure four unit balanced armature earphone tends to be young and bold, just like the sharp, firm, passionate and clear sense of love and hate of BMW, without any delay.
Distinctive visual aesthetic feeling, design inspiration comes from water ripple
Panel grain comes from the different configuration of water, there is the elegance of small bridge and flowing water, the tranquility of shimmering light, and the surge of stormy waves, so as to show the sound of earphones is both exquisite and beautiful and majestic. On the color collocation, there are red of burning sun, blue of sea and cloud sky, black of dark night, white of The Opening of Chaos, it brings the pleasing sounds of natural sound for you.
The body lines are beautiful
Good design comes from trial and error. After many day and night ideas, the design team sketched out three kinds of complex technology, visual rich texture cover plate. The panel pattern changes layer by layer, showing a vivid and colorful shape. The 3D printing cavity is matched to make the earphone model more eye-catching, which is both aesthetic and dynamic.
Good wear, is to forget to wear
Sampling the ear data model of thousands of celebrities around the world, combine the cognition and feeling of the collector to create a comfortable shape, and give you a customized wearing experience. In terms of ergonomics, the shape of the 3D printed headset is very consistent with the structure of human ears, reaching the comfort level comparable to that of a private model.
Unflagging high purity single crystal copper - plated silver cable
Standard high-purity single-crystal copper silver-plated cable can effectively reduce distortion and loss in signal transmission, high-definition sound transmission, more pure and transparent sound quality; MMCX detachable cable design (LC3.5B is the standard cable material) is adopted to meet the needs of a variety of listening sounds, so that the service life of earphones is longer.
Hi-Res high quality audio certification
FA7 has been certified by the Japanese AUDIO association "Hi-Res AUDIO", which brings you a listening experience beyond CD level.
Timbre eartips, 13 pairs of earphone eartips are included
FA7 provides 3 pairs of equalization sets, low-frequency sets, human voice sets and 3 pairs of memory sponge sets of different sizes for large, medium and small sizes. Even the smallest ear canal can adapt easily, truly achieve a variety of personality music scheme.
Specification
Driver: 4BA
Speaker impedance: 23 Ω
Frequency response range: 20 Hz-40k Hz
Sensitivity: 110dB/mW
Rated power: 100mW
Type of plug: 3.5mm gold-plated plug, MMCX detachable cable
Cable length: 120cm
Single weight: 5.3g