Наушники — Binary Acoustics EP321

Binary Acoustics built the EP321 as a universal-fit in-ear model. The Chinese company also trades as Binary Audio and first built its name with the Chopin hybrid made together with Gizaudio. Binary presents the EP321 as the first in-ear monitor in the industry to carry a Direct Drive MEMS driver, a silicon micro-electro-mechanical unit credited to AAC Technologies. The launch price was USD 309.99.

Key specs that matter

Each earpiece holds six drivers in a tribrid layout - a 10 mm dynamic driver, a 6 mm passive diaphragm, three balanced armatures and one MEMS unit. Binary quotes a frequency range of 8 Hz to 40 kHz, an impedance of 13 ohm at 1 kHz and a sensitivity of 122 dB per Vrms, with total harmonic distortion plus noise below 1 %. One earpiece weighs 7.5 g. The cable plugs into standard 0.78 mm 2-pin sockets and is sold with a fixed termination, so the buyer picks either a 3.5 mm single-ended plug or a 4.4 mm balanced plug at the time of purchase.

Engineering and use context

MEMS drivers normally need a dedicated bias supply or amplifier, which has kept them out of passive earphones. Binary gets around this by placing a built-in energizer inside the shell, so the MEMS unit runs from an ordinary headphone output with no special hardware. The signal is split between the driver groups by a physical acoustic crossover working together with an electronic crossover network. The passive diaphragm is not wired to the signal at all and moves with air pressure from the dynamic driver, which lets the low-frequency section work without a second powered woofer. Inner shells are 3D printed from resin with high precision in an ergonomic form, while the faceplates are machined by CNC from stainless steel and carry an irregular geometric pattern that changes colour as the viewing angle shifts. The kit ships with the detachable stock cable and a set of ear tips.

Pairing

With a low impedance and high sensitivity, the EP321 can be run straight from a phone adapter, a compact dongle DAC or a portable player without extra gain. Owners of balanced sources can order the balanced version, and because the 2-pin socket is a common standard, aftermarket cables with other plugs fit directly. Players with a very high noise floor are worth avoiding, since a sensitive load makes any hiss in the output stage easy to notice.

Alternatives

The Binary Chopin is a cheaper hybrid in-ear from the same company, pairing an 8 mm ceramic dynamic driver with three balanced armatures in a three-way crossover.