Наушники — Koss KEB90 Utility

The KEB90 Utility is the in-ear member of the Koss Utility Series, a group of wired headphones announced on 15 November 2021 alongside the KPH40 Utility and the Porta Pro Utility. What ties the series together is a detachable cord system, so the same earphones can move from a 3.5 mm jack to a USB-C or Lightning device by changing the lead instead of the headphone. Koss sells the KEB90 Utility in a Stealth Grey finish, with a regular price of USD 69.99 and a current price of USD 24.99 in its own store.

Key specs that matter

Koss rates the bandwidth at 10 to 25,000 Hz. The dynamic drivers have a nominal impedance of 16 ohms and a sensitivity of 105 dB SPL. The included Utility cord measures 1.2 m and plugs into each earpiece through a 2.5 mm connector, while the other end carries a standard 3.5 mm plug. Packed with the earphones are a carrying pouch, silicone cushions in small, medium and large sizes and foam cushions in small and medium. As a passive wired design the earphone needs no battery, and Koss backs it, like its other wired models, with a Limited Lifetime Warranty.

Engineering and use context

Each rear housing is machined from aluminium, then anodised and laser engraved. Koss angled the stems that carry the dynamic element so the nozzle points into the ear canal on ears of different shapes and sizes. Behind the driver, a rear port covered with stainless steel micro mesh vents the housing, an open-back approach that Koss says relieves pressure inside the enclosure. The cable is flat to resist tangling and has colour-coded strain reliefs that mark left and right. Optional leads extend the connection choices - a USB-C Utility cord with a built-in 24-bit and 96 kHz DAC, an MFi certified Lightning Utility cord, and a Utility Bluetooth adapter, all sold separately or in bundles. The USB-C and Lightning versions add an inline microphone and remote, which the basic analogue lead leaves out. If a cable is damaged, only the lead has to be replaced.

Pairing

The low impedance combined with the high sensitivity means very little voltage is needed, so the output of a phone, tablet or laptop is enough to drive the KEB90 Utility to normal levels. On phones without an analogue jack, the USB-C cord with its own converter takes over the digital-to-analogue stage.

Alternatives

The Koss KEB25i is a noise isolating in-ear model at USD 24.99 with a tubular port structure, a 16 ohm impedance and an inline microphone and remote.