The Hi-X55 is a studio monitoring headphone with sealed earcups and an over-ear fit from Austrian Audio, a Vienna company whose design team consists mainly of former AKG staff. It is built in Austria, and the company calls the model 100 percent serviceable, so parts such as pads, headband padding and cables are replaceable, which extends its working life in busy studios.
Key specs that matter
The Hi-X55 uses a 44 mm High Excursion driver of Austrian Audio's own design, in each earcup, combining an advanced ring magnet system with a copper-clad aluminium coil. Its stated bandwidth is 5 Hz to 28 kHz. Sensitivity is given as 118 dB SPL per volt. Nominal impedance is 25 ohm, harmonic distortion at 1 kHz is below 0.1 percent and rated input power is 150 mW. The maker lists 305 g of weight excluding the lead, and its dimensions are 200 x 170 x 85 mm.
Engineering and use context
The ring magnet layout is intended to improve airflow around the diaphragm while giving a strong magnetic field, and the lighter voice coil lowers the moving mass of the membrane for a faster impulse response. The earcups are double-walled for isolation and can both rotate and tilt, while the headband adjusts in ratcheted steps. Hinges and bow are made of metal, and the frame folds for transport. Comfort relies on slow-retention memory foam under a soft leather-type covering in the ear pads and head bow, and the bow is shaped to ease load on the crown, with a lengthwise slit for ventilation. The removable 3 m lead terminates in a gold-plated 3.5 mm plug, and a screw-on adapter to 6.3 mm and a velvet storage pouch are packed in the box. Replacement ear cushion kits are sold separately, as are spare cables in 1.2 m and 3 m lengths.
Pairing
With a low impedance and a volt-based sensitivity this high, the Hi-X55 reaches working levels from phones, laptops, audio interfaces and mixing desk outputs with no separate amplifier in the chain. Its sealed back keeps leakage low, which makes it practical for tracking with microphones open in the same space.
Alternatives
The Austrian Audio Hi-X65 uses the same driver family in an open-back housing aimed at mixing and mastering.