MMCX — Micro-Miniature Coaxial IEM Connector
Coaxial RF-style connector adapted for IEM cable use. Rotatable joint provides cable-strain relief but loosens over thousands of cycles.
Pinout
Pinout data not yet populated for this connector.
Specifications
| Diameter | 3.5mm |
|---|---|
| Pole count | 2-pole coax |
| Signal topology | single-channel signal + ground |
| Intended use | IEM detachable cable termination |
About this connector
Micro-Miniature Coaxial — an RF-industry connector that the audio industry adopted for IEM cable terminations in the early 2010s. Coaxial geometry: a center-pin signal contact, surrounded by an outer cylindrical ground contact, with a snap-fit retention bead.
Defining feature is the rotatable joint between cable and IEM: the connector spins freely around its axis after engagement, which gives cables natural strain relief and lets ear-hook-style cables sit comfortably on the ear without rotational tension. The same rotatability is the connector’s main wear failure mode — the retention bead progressively loosens over thousands of insertion cycles.
The dominant termination on the Multi-BA IEM and several first-generation hybrid designs. Cable pairing: SPC IEM cable. Compares with the 0.78 mm 2-pin for the same IEM-cable role.
Compatible parts (MPNs)
| MPN | Form | Termination | Plating | Price (USD) | |
|---|---|---|---|---|---|
| MMCX-AU-B | Cable plug, female | Solder | 24K gold over brass | $6 |