Headphones — Azla TRINITY

The TRINITY is a wired in-ear earphone from AZLA, the South Korean earphone brand, developed jointly with Ayuto. It is described as a super-entry concept model, built around three priorities that give it its name, fit, sound quality and cost performance. It was released in July 2025 in Japan at around 1,980 to 2,200 yen.

Key specs that matter

Each earpiece uses an 8 mm Advanced ARD dynamic driver. The diaphragm is a three-layer structure, a very thin PU and PEEK composite film sandwiched between two resin layers, 46 microns thick. Frequency range is 10 Hz to 40 kHz, sensitivity 104 dB SPL/mW and impedance 16 ohms. The housing is aluminium. It carries Hi-Res Audio certification for analogue playback. Two versions are sold at the same price, a standard version with a 1.2 m cable and L-shaped 3.5 mm plug, and a USB-C version with a built-in DAC limited to 48 kHz/16-bit. SednaEarfit T eartips are supplied in four sizes, with a carrying pouch.

Engineering and use context

A dynamic driver's diaphragm should move as a rigid piston, but at higher frequencies it begins to flex in sections, known as split vibration or break-up, which colours the output. Layering a stiff composite film between damping resin layers raises stiffness while absorbing these resonances, which is the purpose of the Advanced ARD three-layer diaphragm. The low impedance and high sensitivity mean the earphones reach a high level from a phone or any portable source. AZLA developed the model over more than a year of trial and error, with the goal of offering a first experience of the wired earphone world at a very low price. The SednaEarfit T eartips use a tapered structure in which the umbrella part curves and thins towards the tip, sealing the ear canal more accurately with less pressure and guiding the sound from the nozzle like a small horn, since the seal determines both isolation and bass response. The USB-C version works with phones that lack a headphone socket, with its DAC using the UAC1.0 standard. Colours include black, blue and champagne gold.

Pairing

The standard TRINITY connects to any headphone output, including DAPs and dongle DACs. The USB-C version suits phones without a headphone socket.

Alternatives

AZLA's ASE-500 is another wired in-ear earphone from the brand, with a housing made of medical-grade silicone.