iBasso IT04 Review

iBasso IT04 Review

Title: A Black Swan



Many of us are familiar with iBasso products, especially with their portable audio players, such as the DX100, DX50, DX90 and DX200 etc. and in-ear monitors such as the IT03 and IT01. Following the success of IT03 and IT01, iBasso has released its flagship IT04, which I will now review for you.



I would like to thank iBasso for providing me the iBasso IT04 as free review sample. I am not affiliated with iBasso beyond this review and these words reflect my true, unaltered opinions about the product.


Price & Warranty:

The MSRP price for the iBasso IT04 Universal IEM is 499.99 USD.

Purchase Link: https://penonaudio.com/ibasso-it04.html


Package and Accessories:

The iBasso IT01 comes in a rectangular black box which is wrapped with a glossy white card box sleeve that sports the brand/model name and an image of the IT04.

This box includes the following contents;

  • 1 x pair of IT04 In-Ear Monitors
  • 15 x pairs of silicone ear tips (5 sorts x 3 pairs in s/m/l sizes)
  • 2 x pairs of foam ear tips
  • 1 x 2.5mm Balanced cable with MMCX connector
  • 1 x 2.5mm balanced female to 3.5mm male unbalanced jack converter
  • 1 x metal carrying case
  • 1 x Warranty Card
  • 1 x Quick Start Guide


The carrying case that comes with the iBasso IT04 is made of two metal parts. On the top of the top cover is the engraved iBasso Audio branding. The lower part has a velvet interior coating which can protect the IEM from scratches and damages.

There is also a round shaped pad that fits into this carrying case where you can put the monitor. This pad has a nice fabric surface that gives the iBasso IT04 a nice look.

The iBasso IT04 comes with a lots of silicone ear tips (15 pairs in total) available in 5 different shapes. Each of these silicone ear tip is available in 3 (three) different sizes, which are small, medium and large. There are also 2 pairs of olive foams that are very comfy and in my opinion a nice addition.

The accessory box is also including a 2.5mm balanced female to 3.5mm male unbalanced jack converter, which looks and feels very well made and is in my opinion a nice addition, which I also expect form other manufacturers.


Design, Build Quality and Fit:

The iBasso IT04 is a nice looking In-Ear Monitor with a semi-custom like shell. This shell is made of acrylic material and is in black color.

On the front of both monitor shells is the faceplate, which has a nice silver carbon-fiber pattern and sports the word InTune.

On thetop of the Monitor shell is the nozzle and near the nozzle is the model name and left / right markings printed in white color. Near the nozzle is the MMCX (Micro Miniature Coaxial) female connector, which has a robust build quality.

On the top of the nozzle is a metal grid to prevent earwax from entering.

On the inner side of the acrylic shell is a small vent for the pressure relief.

The overall build quality of the acrylic housing and of the connectors is top notch!

The monitor is ergonomic and has an above average isolation that is quite enough to wear it in the public and fairly noise environments like bus, train etc.




The Cable:

The CB12s that comes with the iBasso IT04 is a hand braided cable, which is made of an 8 core mono crystal silver & silver plated mono crystal copper that is terminated with a 4 pole, 2.5mm TRRS (balanced) gold plug.

There is also a 2.5mm TRRS to 3.5mm TRS cable adaptor that allows the IT04 to work as a single ended IEM that is included to the package as standard accessory.

The cable and the adaptor are looking awesome. The build quality is great and there is a visible improvement over the stock cable of the IT03 and IT01.




The iBasso IT04 is a hybrid In-Ear Monitor with a 3 + 1 driver configuration.

The dynamic driver of the IT04 is an in-house developed speaker that utilizes a magnetic flux approaching 1 Tesla with a 10mm grapheme diaphragm.

The 3 balanced armature drivers of the company Knowles with the model Nr. 30017.

The iBasso IT04 features also a patented technology called Root Tube Internal Design to bring out the max. potential of the drivers.




  • Frequency range: 5Hz-40kHz
  • Sensitivity: 110+/-2dB
  • Impedance: 16Ω
  • Passive noise reduction: -30dB
  • Rated power: 10mW
  • Distortion:<1%THD(@1kHz/1mW)
  • Cable length: 120mm
  • Net weight: 13g
  • Plug: 2.5mm gold-plated plug


Equipment’s used for this review:

IEM’s              : iBasso IT04, Campfire Audio Polaris, IMR Acoustics R1
DAP&DAC’s  : Sony WM1A, Cayin N5II, Fiio M7, Chord Mojo, Xduoo XD10, Audirect Beam


Albums & tracks used for this review:

  • First Aid Kit – My Silver Lining (Spotify)
  • London Grammar – Interlud (Live) (Flac 24bit/44kHz)
  • Laura Pergolizzi – Lost On You “Live at Harvard and Stone” (Tidal Hi-Fi)
  • Minor Empire – BulbulumAltinKafeste (Spotify)
  • Leonard Cohen – You Wnt it Darker (Spotify)
  • Dave Gahan – Kingdom (Tidal Hi-Fi)
  • Eric Clapton – Wonderful Tonight True (Flac 24bit/96kHz)
  • Casey Abrams – Robot Lover (Tidal Hi-Fi)
  • Vivaldi – Le QuarttroStagioni “The Four Season” (Tidal Hi-Fi)
  • Otto Liebert& Luna Negra – The River (DSF) – Binaural Recording
  • Future Heroes – Another World (Tidal Hi-fi)
  • Lorde – Team (Flac 24bit/48kHz)
  • Tom Player – Resonace Theory “Album” (Tidal Hi-Fi)
  • Massive Attack – Angel (Tidal Hi-Fi)
  • Portishead – It Could Be Sweet (Spotify)
  • Liquid Tension Experiment 2 – Acid Rain (Spotify)
  • Opeth – Damnation (Tidal Hi-Fi)
  • Metallica – Sad but True (Flac 24bit/96kHz)
  • Megadeth – Sweating Bullets (Tidal Hi-Fi)
  • Slayer – Angel of Death (Spotify)



The iBasso IT04 is a sensitive and efficient In-Ear Monitor with a relative low impedance of the 16 ohm’s. The IT04 is an ideal IEM for the use with portable sources like phones, tablets, etc. and can be driven to very loud volumes without the need of an external amplifier.



The Sound:

The iBasso IT04 is a relative balanced sounding In-Ear Monitor with a mildly V shaped sound signature. The midrange sounds quite natural and transparent, the bass is fast and gently pronounced and it has a detailed treble range.


The Bass:

The iBasso IT04 has in general a slightly pronounced and pretty linear bass character with a sub-bass depth which is on a pretty good level and emphasis that is neither high nor low. The sub-bass rumble in Massive Attack’s “Angel” and Portishead’s “It Could Be Sweet” is not very intensive, but has moderate depth and quantity.

The bass is fast, clean and detailed but the extension/expansion is a bit short. Particularly admirable is that the bass is reproduced fast, tight, detail and in a controlled manner. This mildly emphasized bass character will satisfy most users in many genres such as metal, jazz, blues or acoustic.

The bass quantity will be sufficient with genres like Edm or Trance music, where the bass need more volume, pressure and good extension than other genres; but those who prefer “bass head-level” performance will not be pleased with the tuning of the iBasso IT04.

The mid-bass region of the iBasso IT04 sounds tight, quick and with above average quantity and body, but has less weight and volume compared to the lower bass regions.

To summarize the bass region, we could say that the iBasso IT04 is an IEM with extremely fast, controlled and detail intensive presentation. The IT04 is the opposite to the entreating bass character of the IT03 with its fast, controlled and highly detailed presentation, which is the main attraction in the bass region.


The Midrange:

The midrange of the iBasso IT04 is slightly recessed due to the mildly V shaped sound signature and has in general a pretty natural and transparent presentation, which is also the main attraction of the IT04 together with its treble range.


a) Vocals:

The iBasso IT04 is pretty successful with female vocals due to its highly pronounced upper midrange presentation, which shows also great detail, emphasis and extension. One other plus point is the transparent presentation of the vocals without to be harsh or sibilant.

I found the IT04 very good with mezzo soprano and soprano female vocals. The ups and downs are very gentle and controlled.

The iBasso IT04 shows a transparent and clear male vocal presentation, without any noticeable muddiness, veil or mixing and sounds quite detailed same as female voices, while I have listened to vocals like Dave Gahan, Leonard Cohen or Eric Clapton. But I would wish that the IT04 have had slightly more mid-bass body and depth, which would make the presentation male vocals even more successful.


b) Instruments:

The instruments presentation of the iBasso IT04 is slightly bright, neutral, natural and shows a tonality, which sounds neither thin nor too thick. Instruments sounding detailed and airy, followed with great separation and definition. Instruments such as pianos are slightly bright and emphasized, acoustic guitars are pretty natural, transparent and fast, while violins are slightly bright without to be harsh. Violas are quite successful except for a little lack of warmth and body.

The iBasso IT04 has a quite precise vocal and instrument placement, while the general performance regarding to instrument separation is above average.


c) Upper Midrange:

The upper midrange of the iBasso IT04 is highly emphasized and shows a transparent and neutral presentation, without any roll-off, while all of these factors are adding detail and airiness to the overall presentation. Instruments in metal music such as cymbals, drums or guitars and also vocals are sounding very clear. The IT04 is showing a great performance with its clearness and detail retrieval in moments where guitars have high distortion, which is really rare to find in this price range.

Guitar solos and guitars like in Megadeth’s “Sweating Bullets”, Slayer’s“Angel of Deaths” and Rush’s “Leave That Thing Alone” songs with high distortion are very detailed and successful. Some instruments such as flutes sounding enthusiastic and lively, while pianos have enough brightness and emphasis.


The Treble Range:

The treble presentation of the iBasso IT04 is transparent, neutral and slightly bright in its tonality. The peak of the treble range is around 8kHz and is rolling of slowly after this point, which was a good decision, because a peak around 10kHz could be too much for treble sensitive listeners, while 8 kHz makes the sound detail without to be ear-piercing/fatiguing.

The treble performance of the iBasso IT04 in terms of extensions, quantity and airiness is above average, while instruments like cymbals in metal music such as hi hats are prominent and countable and crash cymbals have a pretty quick and controlled decay. It is a pleasure to listen jazz music, especially pianos where the IT04 performs very well in fast passages.

The transparent, airy and spacious presentation of the iBasso IT04 makes it a demanding IEM for many types of music.


The Soundstage:

The soundstage of the iBasso IT04 is pretty spacious and could be descript as very large for an In-Ear Monitor. The IT04 lets space between instruments in horizontal array, which makes the overall presentation airy and spacious. The soundstage depth is also pretty successful, but is less impressive compared to the glorious wideness.



iBasso IT04 versus IMR Acoustics R1

Both the iBasso IT04 and IMR Acoustic R1 belong to the same class and are one of my favorite In-Ear Monitors in this price range.

Unlike the IT04, the IMR R1 has a variety of filters and tuning options that can chance the sound to neutral, warm or thick, while the IT04 has in general a pretty neutral and transparent tonality.

Both IEM’s have a fairly deep sub-bass presentation, while the IMR R1 is superior to the IT04 in terms of quantity and emphasis. The bass speed and control of this IEM’s is successful, while the iBasso IT04 has the slightly edge in overall performance.

The IMR R1 is a bit more detailed in the bass department.

The iBasso IT04 has a slightly recessed midrange presentation due the mildly V shaped sound signature that I mentioned before. The midrange of the IMR Acoustics R1 on the other hand can vary noticeable by the use of the tuning filters.

The midrange of the iBasso IT04 is superior to the IMR Acoustics R1 in terms of transparency and airiness. When it comes to the vocal presentation, I can say that the IMR R1 is more successful with male vocals, while the iBasso IT04 performer better with female vocals.

Both IEM’s have a quite detailed and controlled upper midrange presentation, while the iBasso IT04 is superior to the IMR R1 in terms of upper midrange detail and definition.

The iBasso IT04 and IMR Acoustics R1 are technically successful in the treble range, while the IT04 is superior to the R1 because of its better treble extension, the quantity and more natural presentation. Both of those IEM’s have an airy and spacious treble reproduction.

When it comes to the soundstage performance, I can say that both In-Ear Monitors sharing a satisfying soundstage width and depth performance, while the iBasso IT04 shows better width and the IMR R1 slightly more depth.


iBasso IT04 versus Campfire Audio Polaris:

Both of those In-Ear Monitors are sharing an adequate sub-bass depth, with moderate intensity and quantity. The iBasso IT04 shows slightly more sub-bass depth than Campfire Audio Polaris.

The game is changing when it come to the midrange region, where the Campfire Audio Polaris shows more quantity and intensity. The midbass of the IT04 sounds lighter accented/emphasized than those of the Polaris. But I can say that the iBasso IT04 is superior to the Campfire Audio Polaris in terms of overall bass speed and detail.

When it comes to the midrange presentation, I can say that the CA Polaris has the more aggressive V shaped sound signature with, while the iBasso IT04 sounds less recessed in the midrange, which is also one of the reasons that the IT04 sounds more detailed. The iBasso IT04 sounds also cleaner and more transparent than CA Polaris.

Both IEM’s are successful while listening to vocals, but the IT04 sounds lusher with female voices Laura Pergolizi or Aretha Franklin, while the Campfire Audio Polaris is more suitable to listen male vocals like Eric Clapton or Leonard Cohen. The detail of instruments is pretty high with both of these IEMs, while the overall performance of the IT04 is slightly better than those of the Polaris.

The upper midrange of the IT04 and Polaris sounds quite controlled. The iBasso IT04 has the upper hand in terms of definition and detail, while the CA Polaris is bit more controlled in this frequency range.

The technical ability and extensions of the treble range of both IEM’s is relative good, but the iBasso IT04 is superior to the CA Polaris in terms of quantity, intensity and detail. The treble range of the IT04 and the Polaris is airy and spacious.

When it comes to the soundstage performance and separation of instruments, I have noticed that both In-Ear Monitors have enough width and depth for a relative precise separation. The iBasso IT04 has more width, while the CA Polaris is more successful in terms of soundstage depth.




The iBasso IT04 is a milestone in the evolution of the companies In-Ear Monitor history. It looks sexy with the carbon fiber elements on the face plate, is comfortable to wear and has a quite mature sound tuning that represents a smooth bass response, detailed midrange and airy treble tuning, which is followed by a glorious soundstage performance. All of those elements making the iBasso IT04 to a great option for those, who are looking for something that is rarely found under the 1000 USD price tag.


Pros and Cons:

  • + Very detailed treble range
  • + Airy Presentation
  • + Fast bass response
  • + Performance of female vocals
  • + Spacious/Open Sound
  • + Wonderful faceplate design and hybrid cable


  • – Mid-bass body
  • – Fullness in the midrange


You may also like...

1 Response

  1. An outstanding review as always dear expert audiophile and reviewer Mr. Moonstar . Let me congratulate you for this amazing work gentleman . Wish you the best for your upcoming reviews .

Leave a Reply

Your email address will not be published. Required fields are marked *