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Sony IER-M9 Review

Like most Sony headphones, the emergence of the IER-M9 in 2018 took the global audio market by storm.

These in-ear headphones are incredibly solid, making it almost difficult to pinpoint a single flaw. No doubt, audiophiles would appreciate what the Sony IER-M9 brings to the table.

The Sony IER-M9 undoubtedly oozes excellence in many ways ranging from its impressive build quality to its outstanding features.

In this enlightening review, we will shed light on the Sony IER-M9 and let you in on the different shades of awesomeness they have to offer.

As you keep reading, you will discover why these headphones are widely recognized as one of the best headphones in today’s market.

Read on!

Specifications of the Sony IER-M9

Here are the specifications of the Sony IER-M9:

  • Weight: 11.0 g
  • Headphone type: Closed, Penta Balanced Armature
  • Headphone design: In-ear (Intra-aural), Closed back
  • Wearing style: Ear clip
  • Connectivity technology: Wired
  • Connector plating: Gold
  • Number of Drivers: 5
  • Driver Unit: Penta Balanced Armature
  • Active noise cancellation: No
  • Maximum power handling: 100 mW
  • Audio connector to headphones: 2 × MMCX
  • Audio connector to source: 1 x 1/8″ / 3.5 mm TRS Male Right-Angled, 1 x 4.4 mm TRRRS Male Right-Angled
  • Impedance: 20 ohms (at 1kHz)
  • Frequency response: 5Hz – 4000 Hz
  • Sensitivity: 103 dB/mW
  • Cord type: Y-type, detachable
  • Cord length: Approx. 1.2m
  • Cord conductor material: Oxygen-Free Copper, Silver material
  • Plug: L-shaped non-magnetic gold-plated stereo mini-plug, L- shaped non-magnetic gold-plated balanced standard plug
  • Water resistance: None
  • IP rating: None
  • Weight: 0.4 oz/11 g

What is in the Box

  • Shirt Clip
  • Cable holder
  • Clean cloth
  • Carrying case
  • Documentation
  • Unbalanced OFC MMCX cable with 3.5 mm connector
  • Balanced OFC MMCX cable with 4.4 mm connector
  • Sony IER-M9 Headphones
  • Triple comfort earbuds (SS, S, MS, M, ML, and L)
  • Hybrid silicone earbuds (SS, S, MS, M, ML, L, and LL)


These headphones have a comfortable and lightweight design that feels magical. At times, you might even forget you are wearing them, and they fit so well that you enjoy every second you spend lost in the music. With the Sony IER-M9, your comfort is assured.

There are different earbuds and sizes available for you to choose from, namely the triple comfort earbuds and hybrid silicone earbuds. You certainly find a snug fit for your ear shape.

Research shows that most Sony IER-M9 users prefer the triple comfort earbuds because they feel like a good mix of silicone and foam tips, which makes them ultra-soft when inserted into the ears.

However, what matters is what works best for you and that could be the hybrid silicone earbuds. So, it’s up to you to find the best fit, rock them, and create memorable music listening memories.


The Sony IER-M9 is made of magnesium and features a simple but attractive matte black finish. Also, the driver housing of these headphones is quite light.

And what’s more, the shape of the driver housing comes with curves that allow these headphones to sit comfortably in your ears. The design of these headphones might be simple; nonetheless, it leaves a lasting impression on most users.


Without a doubt, the Sony IER-M9 produces a detailed and evenly balanced sound that is easy on the ears. These headphones are ideal for a wide variety of musical genres, including Jazz, Soul, Rock, Classical, Pop, and the like.

Hence,  if you are in need of an excellent sounding headphone, the Sony IER-M9 is an excellent option to consider.

Below is a detailed sound profile of the Sony IER-M9.

Low Ends

The low end of the Sony IER-M9 provides energy and detail to a high degree. It offers accurate and natural sound that is also engaging and fun.

If you are a basshead or bass enthusiast, you will appreciate the bass performance of these headphones, especially when you use them to listen to pop.

The bass has an energetic grip that adds tightness to lively or fast tracks. Similar to the Sony IER-M7, the low end is well-separated from the higher frequencies, providing a smooth feel while still throwing a bit of warmth into the mix.

Articulate and full, this sound gains from the emotive and powerful bass. Deep without sounding sloppy or overblown, the impact registers with a unique sharpness.


The mids of these headphones are ever-present, clean, rich, and well-balanced. It can be distinguished from the other parts of the frequency range without sounding too far away.

The mids do not show any distortion or compression. This contributes significantly to its sensation. In a nutshell, this midrange provides you with a memorable listening experience that blends impressively with the general sound of the Sony IER-M9.

High Ends

The balance of the high-end is pretty impressive. It provides excellent detail without sounding piercing or too bright.

Whether you are focusing on the vocals or instrumentation, you can be sure that the separation of the highs and level of clarity these headphones offer won’t disappoint you at all.


No doubt, the Sony IER-M9 delivers a good spacious sounding soundstage. The soundstage of these headphones is airy and deep.

Here, every note stands out in sharp contrast to the other. Additionally, there is a broad space between every instrument.

Having said that, the soundstage of these headphones may suffer a bit on extremely intricate classical tracks.

Pros and Cons


  • Comfortable fit
  • Lightweight
  • Impressive sound
  • Excellent build quality
  • Great all-rounder


  • Bass might be too strong for some individuals

Final Words

The Sony IER-M9 reproduces a lively, realistic headroom in the head of every listener. They provide users with a good mix of excellent sound and sound monitoring.

The Sony IER-M9 can do it all. Little wonder why they are referred to as “unique all-rounders” in today’s audio market. Although these headphones cost around $1000, you can rest assured that they would be worth the trouble.

These headphones give you the opportunity to enjoy music the way it ought to be — without restraint or exaggeration.

Now, all sound lovers and music professionals can enjoy music like never before with a big smile.

Do you desire to enjoy the ultimate music listening experience?

Don’t think twice.

Get yourself the Sony IER-M9 and bring your desire to life.

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