Linsoul Kiwi Ears Quartet IEM for HiFi

If you want a hybrid in-ear monitor that focuses on clean low end without losing clarity up the frequency range, the Kiwi Ears Quartet is built for you. The tuning approach is designed to deliver strong, well controlled bass alongside mids that stay natural and detailed, making it useful for studio listening, live practice, and gaming audio. With its purple hand crafted resin shell and a detachable cable setup, it is also practical for musicians who need a dependable, removable connection.

The Quartet name points to its four-driver arrangement, where the drivers are tuned to work together rather than simply adding together. According to the manufacturer, the blend of dynamic drivers and balanced armatures is intended to keep vocal presence and instrument detail crisp while still delivering impact in the sub-bass and bass region. 🎧

Key features

The most distinctive aspect is the hybrid driver design. The Quartet uses an isobaric double dynamic driver subwoofer concept, built around two 10 mm titanium diaphragm drivers with dual magnetic circuits. The goal, as described by Kiwi Ears, is to achieve sub-bass that reaches deep while staying tighter and faster, with less risk of cancellation through passive phase alignment.

Alongside that low end emphasis, the tuning is designed to be balanced rather than just boosted. The manufacturer states that the bass and sub-bass emphasis begins at 350 Hz, while the mids from 350 Hz to 1 kHz are tuned to be completely flat. That matters if you rely on accurate midrange tonality for vocals, guitars, and rhythm parts rather than only enjoying a heavy, bass-first sound.

There is also an attention to treble detail through a dedicated balanced armature setup. The Quartet includes a custom mid high frequency balanced armature driver and a custom ultra high tweeter balanced armature driver. The manufacturer describes these as being tuned with a venting system to provide airflow, and with a passively tuned target curvature intended to keep the mid treble clean without sounding dulled or overly sharp.

For day to day use, the Quartet is positioned as something like neutral studio monitors, but with sub-bass and bass emphasis that adds body and texture. If you are a performance drummer or bass guitarist, that extra weight from the lower frequencies can help your kit or bass line feel present, without muddying the mid band. If you are mainly a music listener, the appeal is the combination of quality bass and natural tonality.

Another practical highlight is the detachable cable. The IEM includes a removable 2 pin connector system, so you can swap to other 2 pin cables when your setup needs it. That can be handy if you want one cable for desk use and another for travel or practice.

Tech specs

• Type: Hybrid in-ear monitor with 2DD and 2BA drivers
• Driver configuration: Isobaric double dynamic driver subwoofer design
• Dynamic driver size: 10 mm titanium diaphragm drivers
• Crossover reference: 350 Hz passive low-pass network
• Midrange tuning range: 350 Hz to 1 kHz tuned to flat
• Connector: Detachable removable 2 pin connector system
• Shell: Hand crafted medical-grade resin, cured and polished

What stands out

One of the key reasons people choose a hybrid monitor is the balance between impactful lows and detailed mid and treble presentation. In the Quartet, Kiwi Ears focuses on sub-bass extension and control through the isobaric double dynamic approach, with passively aligned drivers intended to reduce soundwave cancellation. The result, according to the manufacturer, is sub-bass that is deeper while also feeling tighter and quicker.

At the same time, the tuning intent is not to push everything into the bass. The mids are treated carefully, with the manufacturer stating that the 350 Hz to 1 kHz region is tuned to be completely flat. That is a useful reference point for anyone who wants voices and key harmonics to remain accurate, and for players who need their phrasing to translate cleanly.

The balanced armature drivers are tuned to support crisp mid treble character. Kiwi Ears describes the goal as clean tone for vocals and instruments without dullness or a nasally edge. It is a subtle but important kind of engineering, especially if you listen for articulation, cymbal texture, or the bite of plucked strings.

Finally, the physical build is designed to be wearable. The shells are hand crafted using medical-grade resin, cured and polished, with the aim of a durable finish that is safe against skin. With its detachable 2 pin connector system, the Quartet is also easier to manage in a musician or DJ style workflow where cables can get swapped quickly. Purple is included as part of the supplied finish, giving you a distinct look without affecting performance. 🎶

It’s not only for one audience. It makes sense if you prioritise strong and impactful lows, but you still want neutral mids and upper mids for natural tonality. It may not suit you if you prefer a purely bass free, strictly flat sound across the whole range, because the manufacturer describes bass emphasis beginning at 350 Hz.