**Electro Audio World's take :**

I finally have the open back IEM I've been waiting for, and I want to share my first impressions with you.  
  
At the heart of the Septet lies an extremely sophisticated Quadbrid architecture:  
  
1x Dynamic Driver: Responsible for bass and sub bass reproduction with excellent physicality and extension.  
  
4x Balanced Armatures: Handle critical mid and lower treble regions through a carefully implemented crossover network.  
  
1x Micro Planar Transducer: Designed for ultra high frequency extension and air recovery.  
  
1x Piezoelectric Driver: Provides extra brightness, harmonic information, and high frequency energy.

\* \* \* [To read the full review, including source matching and comparisons with other IEMs, click here.](https://www.head-fi.org/showcase/kiwi-ears-septet.28165/reviews#review-43377)

On paper, this combination seems a bit extreme. But in practice, it creates something truly unique. And we're talking about an open back IEM.  
  
The Septet doesn't sound like a traditional hybrid. It doesn't sound like a planar IEM. It doesn't sound like a fully balanced armature focused monitor. Perfectly arranged and wonderfully tuned, it occupies a fascinating middle ground between them all.  
  
Unlike most closed shell headphones, the Septet creates an impression of air freely moving around the instruments. The notes seem less constrained by physical boundaries. The sound breathes naturally. The open back architecture plays a big role here.

  
Don't get me wrong, there's pretty good isolation here with a tip that fits you right out of the box. You don't hear distracting noises from the outside, but these headphones have an open back design, and you feel it while listening.  
  
Instead of the typical in ear presentation seen in many IEMs, the Septet projects music into a much wider acoustic environment.  
  
It's immediately noticeable with live recordings, orchestral works, acoustic jazz, and progressive rock. The listener is offered an unusually wide soundstage for an IEM in this price segment.  
  
Many wide sounding IEMs achieve their wide presentation by thinning out the note weight. The Septet completely avoids this mistake.  
  
The bass remains strong. The vocals remain stable. The treble remains extended. Everything feels connected. This consistency is perhaps the greatest success of Kiwi Ears' crossover implementation.  
  
The dynamic driver bass, the balanced armature midfrequencies, and the transition between planar air and piezoelectric glow are exceptionally seamless.  
  
At no point does the listener realize that the individual drivers are operating independently.  
  
The entire system acts like a single transducer. And this is a much more difficult task than most enthusiasts realize. However, I must say very clearly that this IEM demands more power than other ordinary IEMs. If possible, you should power the Septet with a good DAP or a powerful DAC amp. That's when the experience becomes completely different.

\* \* \* [To read the full review, including source matching and comparisons with other IEMs, click here.](https://www.head-fi.org/showcase/kiwi-ears-septet.28165/reviews#review-43377)

  
**Pros**: 

Open soundstage thanks to open back design  
High resolution quad driver system with excellent technical capabilities  
Deep, textured and layered bass performance  
Clear and prominent midfrequencies with strong vocal intelligibility  
Excellent treble extension with planar and piezoelectric synergy  
Strong scalability across different source qualities  
Maintained core tonal identity in all tested DAC and DAP pairings  
Lightweight, ergonomic and robust full metal body design  
Modular quality cable system with 3.5mm and 4.4mm support

**Cons**: 

Requires higher quality and more powerful sources to fully demonstrate its technical potential  
Open back design may cause some sound leakage, limiting portable use scenarios.  
May produce a slightly bright or energetic sound with very detailed sources

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**All photos were taken by ADR >>** [**Instagram:** **u/electroaudioworld**](https://www.instagram.com/electroaudioworld/)  
  
**Used photo Gear : Sony A7 III + Sigma 24–70mm F/2.8 DG DN II Art Lens**  
  
**.**

Open Back and Unique Driving Technology - Full Review of Kiwi Ears Septet ($269)