Наушники — Koss Sparkplug

The Sparkplug is a corded earphone from Koss, the Wisconsin headphone pioneer. It is an inexpensive everyday earphone built around a dynamic driver and memory-foam ear cushions that expand to seal the ear canal, giving it strong passive isolation from surrounding noise. It is also offered as the Sparkplug VC with an in-line volume control.

Key specs that matter

A single moving-coil driver per side covers 10Hz to 20kHz, impedance is 16 ohms and sensitivity is 112dB SPL/1mW. The straight, dual-entry cable is 1.2m long and ends in a 3.5mm stereo plug. The ear cushions are slow-recovery memory foam made from hydrophilic formed urethane. It is available in black and white, and the VC version adds an in-line volume control and a carrying pouch.

Engineering and use context

Memory foam is compressed before insertion and then slowly expands inside the ear canal until it fills the space, forming a custom seal for each wearer every time the earphone is used. That seal is what the Sparkplug relies on for both isolation and bass - in a sealed in-ear design, the driver pressurises the small volume of the closed ear canal, so low frequencies are reproduced directly rather than being lost through gaps, which is how a small driver reaches such deep bass. The hydrophilic urethane absorbs moisture, which helps the foam stay comfortable during long wear. Because it blocks outside sound passively, the Sparkplug lets the wearer listen at lower volume in noisy places such as public transport, which is gentler on hearing than raising the level to mask the environment. The low impedance combined with high sensitivity means the earphones reach high levels from the weak headphone outputs of phones, laptops and portable players without an external amplifier. Its Y-shaped cable feeds both earpieces directly, a simple and durable layout. With no microphone or electronics, the Sparkplug connects to any device with a 3.5mm headphone socket, and it needs a USB-C or Lightning adaptor for phones that lack one. Foam cushions wear with use and are replaceable.

Pairing

The Sparkplug works directly with phones, tablets, laptops and portable players with a 3.5mm output, and its sensitivity means no headphone amplifier is required. Its strong isolation suits commuting, travel and noisy environments.

Alternatives

Koss's own BT115i offers a Bluetooth in-ear alternative with an in-line microphone and a cable-free connection to the phone.