Sennheiser IE 900 Wired In-Ear Earphones – Aluminium

The Sennheiser IE 900 uses a single 7 mm TrueResponse dynamic transducer in each precision-milled aluminium earpiece. Its X3R acoustic system combines three resonator chambers with an acoustic vortex to control resonances without relying on multiple drivers. The earphones are wired and use Fidelity+ MMCX cable connections with adjustable ear hooks. Manufacturer-listed cable options include 3.5 mm single-ended and 2.5 mm and 4.4 mm balanced plugs, so the chosen cable must match the headphone output on your source. Balanced wiring is optional rather than a guaranteed upgrade for every system. The 18-ohm impedance is not a reason to claim a particular amplifier is mandatory. Appropriate ear tips provide passive isolation; these earphones do not offer Bluetooth or active noise cancellation. This listing is the Aluminium IE 900, not a complete music-player system.