Fiio FX15 Tribrid In-Ear Monitors

The FiiO FX15 marked FiiO's first step into electrostatic in-ears, and it arrived swinging. Each side combines a 10mm DLC dynamic driver, a Knowles balanced armature and four Sonion electrostatic drivers, with a clever physical switch that lets you hear exactly what the electrostatics bring to the table.

It sits near the top of our IEM collection and remains one of the most distinctive tribrids at its price. See more from FiiO.

Type and Technology

Six drivers per side in a true tribrid arrangement. The 10mm DLC (diamond-like carbon) dynamic driver anchors the low end, a custom Knowles balanced armature carries the midrange, and four Sonion electrostatic drivers handle the ultra highs with reach out to 40kHz. A dedicated EST level switch on each earpiece toggles the electrostatic drivers, so you can A/B their contribution in real time and set the top end to taste.

Sound Character

The FX15 pairs a warm, textured dynamic foundation with articulate mids and an unmistakably airy, feathery treble that only electrostatics deliver. With the switch engaged, cymbals, strings and room ambience gain shimmer and space; with it off, the presentation becomes smoother and more relaxed. At 24 ohms and 103dB/mW it appreciates a capable source, so consider pairing it with a player from our DAP collection.

Build and Comfort

The shells are compact and light at roughly 6 grams each, shaped for a secure over-ear fit. Expanded MMCX connectors make cable swaps easy, and the included cable is an 8 strand, 224 wire high purity silver design with twist lock interchangeable 3.5mm and 4.4mm plugs.

Best For

Detail oriented listeners who want electrostatic air without a flagship price, and anyone curious to hear what EST drivers actually do, thanks to the on/off switch.

What's in the Box

• FX15 in-ear monitors
• 8 strand high purity silver MMCX cable
• Twist lock 3.5mm and 4.4mm audio plugs
• Multiple sets of silicone ear tips (bass, balanced, vocal)
• Memory foam ear tips
• Leather storage case
• MMCX removal tool and cleaning brush
• Quick start guide and warranty card

Specifications

What Reviewers Say

in-Ear Fetish highlights the FX15's electrostatic treble air and switchable EST drivers in his hands-on review.