Наушники — Koss ED1TC

The ED1TC is an institutional on-ear headphone from Koss, built for schools, libraries and training departments where one pair passes between many users in a day. Koss, based in Milwaukee since John C. Koss and engineer Martin Lange Jr. created the SP/3 stereophone in 1958, says it has supplied education headphones for more than six decades, and the ED1TC is one of the simplest models in that range at a list price of USD 9.99. It comes in a grey and silver finish and carries a lifetime limited warranty from Koss.

Key specs that matter

A dynamic element in each cup covers 100 Hz to 20,000 Hz according to Koss. Impedance is 32 ohms and sensitivity is 98 dB SPL, with distortion given as below 0.5 percent. The cable is a straight, single-entry cord 1.2 m long that ends in a 3.5 mm plug. There is no microphone, no volume control and no battery, so the headphone does one job and has few parts that can fail.

Engineering and use context

Koss moulds the ear cups and housing from ABS plastic instead of fitting foam cushions, and it points out that this avoids the crumbling and flaking foam that shared headphones tend to suffer after months of use. The plastic cushion forms a seal against the ear that cuts ambient noise getting in and sound leaking out, which matters in a classroom where several students listen at once. Every part can be wiped down using alcohol-based cleaner on a soft cloth between users, keeping hygiene simple for staff. The adjustable headband and cup shape are sized to fit heads from young children to adults, so one model can serve a whole school. With single-entry wiring the cable reaches the headphone from one side only, leaving one lead to route and less to snag on desks or chair legs. Koss sells the ED1TC in the same education range as the UR5, KPH7, KPH8, UR10 and ED1TCi, giving buyers several price points for bulk orders.

Pairing

With its low impedance and good sensitivity the ED1TC runs directly from the headphone output of a classroom computer, laptop, tablet or media player without any amplifier. The plug fits the standard stereo socket on these devices, and the cord gives enough reach from a desk to a seated listener. The limited bass extension points to spoken word, lessons and audio books as the main material, rather than music listening at home. Schools that need students to talk during lessons or tests should choose a version with a microphone.

Alternatives

The Koss ED1TCi uses the same wipe-clean plastic cups but adds a push-to-talk mic in the cable, on a dual-entry cord, for USD 14.99.