Overview

This listing is for a FiiO FA7S six-driver balanced armature in-ear monitor in used, pre-owned condition. Each earpiece uses six balanced armature drivers in a three-way, "2+2+2" crossover: two Knowles drivers handle bass, two Knowles drivers handle treble, and two custom FiiO-tuned drivers cover the midrange, keeping vocals natural while bass stays controlled and highs stay resolved. The housings are machined from medical-grade 316L stainless steel through a powder-metallurgy process, then finished with a five-axis CNC faceplate and PVD coating for a durable, mirror-like look. Because this pair is used, expect normal signs of previous handling, and note that it does not ship with full original retail packaging — see the listing photos for actual condition.

Simcoe Audio Video Insight

The FA7S's "2+2+2" crossover is worth understanding before you buy: it's not just six drivers stacked together, it's two dedicated to bass, two to treble, and two custom FiiO-tuned drivers specifically handling the midrange where vocals live. That's part of why the tuning stays natural on vocals even with six balanced armatures working at once. Buying this one in pre-owned condition still gets you that same driver layout and the stainless steel, PVD-finished shell — just expect it to show some signs of prior use, so check the listing photos closely before deciding.

Best for the FiiO FA7S (Used): Take advantage of the twist-lock swappable plug system — 2.5mm, 3.5mm, and 4.4mm — to match whatever source you already own rather than needing an adapter.

More Details

Why It Wins

• 6-driver, "2+2+2" crossover: two Knowles drivers for bass, two Knowles drivers for treble, and two FiiO custom-tuned drivers for the midrange, keeping vocals natural while bass and highs stay controlled.
• Medical-grade 316L stainless steel housing: five-axis CNC finished with a PVD coating, giving the FA7S a durable, mirror-like shell that holds up better to daily handling than resin shells common at this driver count.
• Twist-lock swappable plugs: 2.5mm balanced, 3.5mm single-ended, and 4.4mm balanced, so the same earphone matches whatever source you're using without needing a separate cable.

What Makes It Different

Many six-driver IEMs use a simpler two-way or generic crossover between bass and treble drivers. The FA7S's three-way "2+2+2" layout gives the midrange its own dedicated pair of custom FiiO-tuned drivers rather than splitting that range across the bass or treble clusters, which is part of why vocals stay clear even with six drivers working together.

Technical Highlights

• Angled, colour-coded MMCX connectors: detachable connectors designed for a secure fit and to make left/right identification straightforward.
• High-purity silver-plated monocrystalline copper cable: 8 strands and 152 wires total, paired with the swappable plug system.
• Hi-Res Audio certified: certified for high-resolution playback, a standard the FA7S carries over from its original retail release.

Buyers Guide

Who This Is For

• The Value-Focused Six-Driver Buyer: Someone who wants FiiO's FA7S sound signature in pre-owned form, and who is comfortable with a unit that's been used but is fully functional and ready to listen.
• The Multi-Source Listener: A listener who owns sources with different plug standards (2.5mm, 3.5mm, or 4.4mm) and wants one earphone that matches all of them via the twist-lock system.
• The Build-Quality-First Buyer: Someone prioritizing a durable stainless steel shell over having sealed retail packaging.

Ideal Use Case

• Practical Step-Up: A practical way to move into a six-driver balanced armature IEM in pre-owned condition.
• Multi-Device Households: Useful for anyone switching between a phone, DAP, and desktop amp with different plug standards, thanks to the swappable connectors.
• Vocal-Focused Listening: The dedicated midrange drivers in the "2+2+2" crossover suit vocal-forward genres well.

What To Pair It With

• A source matching your preferred plug: Since the FA7S ships with 2.5mm, 3.5mm, and 4.4mm options, pair it with whichever source you already use most rather than buying an adapter.
• A portable DAP with a balanced output: Takes advantage of the 4.4mm or 2.5mm balanced plug options for a cleaner signal path.
• A case for the swappable plugs: Keeping the alternate plugs on hand makes it easy to switch sources without hunting for the right one.

Alternative Options

For a new-condition alternative with a similar driver count, FiiO's FH19 hybrid or FA19 all-balanced-armature model are both part of Simcoe's current FiiO lineup, with a different sound signature and driver arrangement than the FA7S. Listeners specifically looking for another pre-owned or open-box option might also consider the FH3 Open Box, which offers a hybrid driver design at an accessible entry point.