COZOY HERA C103 Review













COZOY HERA C103 Review


The Goddess Made of Metal



Cozoy Audio was established in 2014 and is specialized in crafting and designing of Portable Audio Equipments such like Digital to Analogue Converter’s (DAC) and In-Ear Monitors (IEM).

Cozoy Audio’s product design philosophy is to “create fine metallic builds, with leading innovations on circuitry and implementations of cutting-edge metal processing techniques”.

COZOY Website:




The Cozoy Hera C103 IEM was provided to me by Cozoy via Penon Audio for review purposes. I am not affiliated with Cozoy or Penon Audio beyond this review and these words reflect my true and unaltered opinions about the product.




The Cozoy Hera C103 is available for 160 USD on Penon Audio under the following purchase link;

Purchase Link:



Package and Accessories:

The Cozoy Hera C103 came in a stylish black box, which is warped with a glossy cardboard that features the illustration of the In-Ear Monitor and the product branding on the top of it.

This stylish box is containing the following items;

  • 1 pcs x Cozoy Hera C103 In-Ear Monitors
  • 3 pairs x soft silicone ear tips (1 pair in M size came pre-installed)
  • 1 pcs x Cozoy LX Carrying Pouch

The Cozoy Hera C103 is coming with a beautiful Leather Storage Box with premium workmanship that you can purchase it separately under the following link: Cozoy LX Carry Pouch




Design and Build Quality:

The Cozoy Hera C103 is a very robust In-Ear Monitor that features a 9mm diameter single dynamic driver with composite diaphragm technology.

The monitor housing of the Hera is made of two CNC engraved metal parts with a nice polished finish.

On the front part of the monitor are a small vent and the sound nozzle with a fine woven metal mesh on the top to prevent the insertion of unwanted earwax and dust in to the monitor.

The polished metal body is coming with a metallic red finish with artistic patterns on the rear.

At bottom near the cable that is fixed to the monitor shell is a second vent.

The Cozoy Hera C103 has a fixed cable that is adapting a high quality oxygen-free silver plated copper cable, which is to enhance the signal quality and to lower the distortion. The cable is strengthened by Kevlar fiber, which greatly improves reliability while being tangle-free and wear-resistant.

The Hear C103 has left/right indicators on both strain reliefs.

The cable sports a metal Y splitter and chin slider which has a nice polished surface.

The 3.5mm TRS (3 pole) headphone jack has a straight profile and features the same polished metal housing.



Fit and Isolation:

The monitor housing has a medium size and is comfortable wear. The isolation is on an average and is enough to use it in fairly noise public environments such as metro, bus or train.





  • Driver Type                 : 9.2mm diameter Dynamic Driver with Composite Diaphragm
  • Sensitivity                   : 103±3dB @ 1 kHz 0.126v
  • Frequency response   : 10 Hz to 20 kHz
  • Impedance                 : 32Ω±15%
  • Rated Power              : 2 mW
  • Cord                           : L=1.2m
  • Plug                            : 3.5mm Gold-plated




The Hera is an IEM with an impedance of 32ohm and sensitivity of 103dB @1kHz. It can be driven with relative weak sources like smartphones, tablets and smaller sized DAP’s, but shows its true potential if you pair it with more powerful sources like a Portable Amplifier or powerful Players like the QA361.



Equipment’s used for this review:

  • IEM’s                          : Cozoy Hera C103, Shozy Neo CP, TFZ King Ltd
  • DAP/DAC/AMP         : QLS QA361, Cayin N5II, Astell&Kern SR15, xDuoo Poke



Albums & tracks used for this review:

  • Elton John – Your Song (Flac 24bit/192kHz)
  • David Bowie – Black Star (Flac 24bit/96kHz)
  • Dave Gahan – Kingdom (Flac 16bit/44.1kHz)
  • Eric Clapton – Unplugged Album (Flac 24bit/96kHz)
  • First Aid Kit – My Silver Lining (Flac 16bit/44.1kHz)
  • London Grammar – Interlude (Live) (Flac 24bit/88kHz)
  • Laura Pergolizzi – Lost On You “Live at Harvard and Stone” (Wav 16bit/44.1kHz)
  • Rush’s – Leave That Thing Alone (Flac 16bit/44.1kHz)
  • Liquid Tension Experiment 2 – Acid Rain (Flac 16bit/44.1kHz)
  • Opeth – Damnation (Wav 16bit/44kHz)
  • Metallica – Sad but True (Flac 24bit/96kHz)
  • Megadeth – Sweating Bullets (Flac 24bit/96kHz)
  • Slayer – Angel of Death (Flac 24bit/96kHz)
  • Gogo Penguin – Raven (Flac 24bit/192kHz)
  • Otto Liebert& Luna Negra – The River (DSF) – Binaural Recording
  • Vivaldi – Le QuarttroStagioni “The Four Season” (Wav 24bit/88kHz)
  • Lorde – Royal (Flac 24bit/48kHz)
  • Tom Player – Resonace Theory (16bit/44.1kHz)
  • Massive Attack – Angel (Flac 24bit/192kHz)
  • Portishead – The Hidden Camera (MP3 320kHz)



The Sound:

The COZOY Hera is an IEM with a V shaped sound signature. The tonality is warmer than neutral; the bass is deep and strong, while the midrange is musical and the treble fairly soft in its presentation.

PS: This review is written after a burn-in process of approx. 100 Hours. I have used the stock silicone ear tips which are coming with the COZOY Hera.


The subbass area of the Hera shows great quantity with average extension. The subbass has good depth and is pronounced. From the electronic music to faster genres like metal music, the existing subbass quantity and quality is quite satisfying and enjoyable to listen to.

In short subbass of the COZOY Hera is distinctive and pretty dominant in the overall presentation.

The midbass tonality of the COZOY Hera is soft and musical, while the slam effect is quite impressive thanks to the extra subbass emphasis. Instruments like cross drums are pronounced, trumpets are fast and bassy, while bass guitars are a bit warm and thick in its tonality.

The general bass presentation of the Hera shows average speed and control and is pretty tight without to show unwanted situations like muddiness.

From the tracks of Armin Van Buuren to Megadeth, the bass speed is sufficient and satisfactory.


The midrange presentation of the COZOY Hera C103 is clean and musical with average transparency. The area is a bit recessed due to the V shaped sound signature.



The lower midrange of the Hera C103 shows good depth, intensity and warmness, which is the main reason why male vocals are showing a musical and natural tonality. Male vocals don’t sounding muddy and the transparency and clarity are on a fairly good level.

The upper midrange on the other hand is mildly pronounced and is quite controlled. Therefore female vocals are playing in a musical and transparent way without harshness and sibilance, while they are showing a slightly warm and soulful tonality, which is my favorite vocal presentation.



COZOY Hera C103 has a slight warm and musical instrument tonality and everything from the guitar to the violins sounds very natural. Instruments like guitars are a bit warm and pretty clean, while violins are slightly brighter and warmish in it tonality without to show any remarkable sibilance or sharpness. Other instruments such like violas have a thick and quite emotional presentation.


Upper Midrange and Treble:

The COZOY Hera C103 has a soft and controlled upper midrange presentation and is not very upfront or too recessed. The upper midrange transitions are quite soft and controlled without to show any remarkable harshness.

From the female vocals to the instruments such as the violins, pianos or flutes, the upper midrange extension and intensity are moderate. The extension and emphasis of the upper midrange is a bit short for musicality and control, while the existing emphasis and extension is quite sufficient.

The treble range of the COZOY Hera C103 is showing a warmish and thick tonality; it’s not too hot or too bright in its presentation and is highly controlled and musical.

The airiness level in the treble range is moderate, which is enough for a detailed and clean presentation.

The COZOY Hera C103 has a pronounced lower treble range that shows good quantity and extension. In the upper treble range, the emphasis is getting less and the extension is shorter. There is a slight roll-off in this area.

The Hera C103 is representing instruments like cymbals in a warmish and slightly thick way. Other instruments such like Hi-Hats are coming a bit from the background but the hits of this instrument are vivid and pronounced. Crash cymbals have moderate treble intensity and sharpness, while the hits are controlled and are shoeing good extension.


The COZOY Hera 103 has a stage that is sufficient for the separation of vocals and instruments. The soundstage is airy and fairly wide for an IEM at this price range, while the depth of the stage is on an average level compared to the width.



Some Comparisons with other IEM’s:

COZOY Hera C103 versus SHOZY Neo CP

The Shozy Neo CP is a slightly warmer than neutral sounding In-Ear Monitor with an upfront midrange presentation, which is musical and detailed. The bass of this IEM is fast and fairly solid, the upper midrange is lightly pronounced, while the treble is slightly recessed and forgiving.

The COZOY Hera C103 on the other hand is more successful in terms of subbass depth, quantity and midbass intensity compared to the SHOZY Neo CP.

The midrange of the SHOZY Neo CP is more upfront compared to those of the COZOY Hera C103. The Hera IEM is more successful with male vocals, while the Neo CP has the upper hand for female vocals.

The upper midrange of the SHOZY Neo CP is more pronounced and shows better extension. The Hera C103 on the other hand is superior in terms of lower treble (presence) detail and extension, while the upper treble range (brilliance) is slightly recessed on both IEM’s.

The Soundstage of the Neo CP is wider while the Hera C103 is showing more depth.



COZOY Hera C103 versus TFZ King LTD

The sound signature of the TFZ Ling LTD can be described as W shaped, in contrast to the most widely used V shape tuning. The subbass and upper midrange are emphasized, while male vocals are slightly in the background compared to female vocals due to the W-shaped sound signature.

Both of those IEM’s are sharing a pretty similar subbass depth and quantity. The bass of both IEM’s has moderate speed and tightness. The main difference is that the COZOY Hera C103 has more midbass quantity and intensity compared to those of the TFZ King Ltd.

The male vocals of the Hera are more upfront showing more depth and a slightly better detail retrieval, while the TFZ King ltd sounds more pronounced and transparent with female vocals.

The upper midrange of the TFZ King Ltd is more pronounced and detailed than its treble range, while the treble range of the COZOY Hera C103 is more quantity, emphasis and better extension

The soundstage of the COZOY Hera C103 is slightly wider than those of the TFZ King Ltd, while the depth is average on both IEM’s.



The COZOY Hera C103 is an in-ear monitor with a solid metal housing that comes with a nice carrying case. It offers a solid bass performance, a smooth and musical midrange and a fatigue-free treble area that provides enough detail for the price.



Pros and Cons:

  • + Solid Bass Performance
  • + Clean and Musical Presentation
  • + Robust Metal Housing
  • + Beautiful Carrying Pouch


  • – Cables are not detachable
  • – Soundstage has average depth
  • – Needs a bit more power than regular IEM’s



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