The Neumann NDH 30 is a circumaural open-back studio headphone designed as a portable reference for mixing, mastering and precise editing. Its 38 mm dynamic transducers with neodymium magnets work as acoustic dipoles, giving very fast transient response, dry bass, uncoloured mids and transparent highs, while frequency-selective absorbers avoid the exaggerated treble that misleads mix decisions on many headphones. Stereo imaging is precise, and the sound is tuned to match Neumann KH-line studio monitors, so work started at home or on the road carries over to the studio. Build is spring steel and aluminium, the headphone folds for transport and the earpads are replaceable. Frequency range is 12 Hz to 34 kHz, impedance 120 ohms and sensitivity 104 dB SPL, and it weighs 352 g without cable. This silver/anthracite version (catalogue 509111) ships with a detachable 3 m internally balanced straight cable with 3.5 mm plug, a 6.3 mm adapter, cloth pouch and guides. Being open-back, it leaks sound and is not intended for tracking in the same room as a microphone.