Sennheiser IE400PRO sound-isolating, in-ear monitoring headphones offer “distortion-free, natural sound with a punch, transparent mid-range and clear high frequencies”

Announced at the start of 2019, these IE400PRO in-ear headphones (also available in clear finish) are a noticeable step up from the 2018 debut of IE40PRO – yet retain all the simple ‘ticks of the boxes’:

Stereo minijack, with a right-angle plug, all attached to a rugged, 1.3m cable – which is removable from the earbuds.

IE400PRO uses a ‘TrueResponse’ 7mm dynamic single-driver for tremendous resolution, while preventing acoustic stress, even during long periods of use. Distortion, overlapping frequencies and resonance peaks which otherwise usually occur in ‘multi-driver’ earphones are no longer a problem. The distortion factor has been optimised to a previously unimaginable 0.08%. Its miniature design also permits an ultra-compact construction.

The vitals:
Impedance: 16 ohms
Frequency response: 6 – 19,000 Hz
Sound pressure level: 123 dB
THD: < 0.08 % (1kHz, 94dB)
Cable length: 1.3m
Transducer principle: Dynamic
Weight: 18g
Attenuation: < 26 dB