Наушники — Koss KPH30i

The KPH30i is a lightweight open-air on-ear headphone from Koss, introduced in 2021 as a modern, smartphone-ready relative of the company's classic portable headphones. It combines a minimalist headband frame with the same driver specification used in Koss' well-known Porta Pro and KSC75 family, and includes a cable-mounted mic with single-button control so it can double as a headset for calls.

Key specs that matter

The KPH30i uses 35mm dynamic drivers in an open-back on-ear design. Frequency response is 15Hz to 25kHz, impedance is 60 ohms and sensitivity is 101dB SPL at 1mW. The fixed 1.2m cable ends in a 3.5mm TRRS plug with an in-line single-button remote and microphone. Weight is roughly 75 to 80g, and it is offered in several colours such as black, grey, blue and white, including a KPH30i Clear version with a transparent body.

Engineering and use context

The headband uses a newly designed suspension patented by Koss, which positions the earpieces on the ears and spreads contact pressure instead of relying on a tightly clamping headband. Together with the very low weight, this is aimed at comfort over long periods of wear. The cable system was also redesigned, with spring-reinforced strain relief at the points where the cable meets the plug and the earpieces, the areas where lightweight headphone cables usually fail first. The open-air construction lets sound pass through the earpieces in both directions, so the user stays aware of surroundings, which suits office work and walking, but it also means sound leaks out and outside noise gets in, so it is not intended for quiet shared spaces or noisy transport. The TRRS plug carries both stereo audio and the microphone signal, and the single button handles play, pause and answering or ending calls on most phones.

Pairing

The KPH30i reaches full listening levels from phones, laptops, tablets and portable players without an extra amplifier, and its impedance keeps it relatively insensitive to the output impedance of basic sources. On jackless phones, an adapter that passes the TRRS microphone signal is needed to keep calls working through the remote. A small desktop headphone amplifier or dongle DAC adds volume headroom where needed.

Alternatives

Koss' own Porta Pro shares the same electrical specification in a folding form factor with an adjustable comfort-zone setting.