The HIFIMAN HE400se Owner’s Guide provides product overview, specifications, setup, operation, and warranty information for the headphones.
The HE400se is an open‑back headphone with planar magnetic drivers, offering a wide frequency response, high efficiency (91 dB), and a lightweight design (390 g). It includes a detachable cable with 3.5 mm plugs and a ¼" adapter, as well as beveled hybrid earpads for comfort and sound quality.
The guide explains headband adjustment, earpad replacement, break‑in procedure, cleaning instructions, and warranty terms. It also details how to connect the headphones to various audio sources and provides contact information for support and warranty service.
| Frequency Response | 20 Hz – 20 kHz |
|---|---|
| Impedance | 25 Ω |
| Efficiency | 91 dB |
| Weight | 390 g |
| Cable Length | 1.5 m (4.9 ft) |
Move the sliding black block on each side of the headband until the headband rests comfortably on top of your head.
Use a soft, slightly damp cloth; do not use detergents or let any fluid enter the open sides of the headphone.
The HE400se is warranted for one year from the original date of purchase.
Allow at least 150 hours of constant use for break‑in; it does not need to be at high volume.