iBasso. We all know them because of their success in DAP industry. Now they’re in IEM business too. Are they good? We’ll see!

Today we’re taking a good look at the IT03 Semi-Custom IEMs.  Let’s get to it.


Specifications & Highlights

  • Sensitivity: 105 dB/mW
  • FR Range: 10 Hz -30 kHz
  • Rated Power 5mW
  • Impedance: 8 ohm
  • 9.2mm 1DD + 2BA driver configuration
  • Weight: 9 grams without the cable
  • MSRP: 259 USD


Testing Equipment

  • Chord Hugo (Main Source)
  • iBasso DX200 (AMP1 BAL – AMP2)
  • Centrance DacPortable
  • BiFrost + H10

Accessories & Packaging

iBasso’s unboxing experience is always neat. This rule does not change with IT03 either. It comes in a durable, medium sized box. No doubt your IEMs will stay safe during the international shipping charade. Inside the box there are 2 compartments. Top compartment is where your IEMs held by a protective foam. Bottom compartment stores tips & carrying case. iBasso included many tips, kudos!

However the carrying case is not very convenient. It is small and feels cramped.

Plus there is no chance fitting IT03 with CB12 in there. Stock cable is glossy, elastic and light. I’ve spotted few micro-creases but nothing major. I can say with confidence that overall unboxing experience is great!

Build Quality

I’ve experienced semi-custom IEMs before. InEar, Fender, ES.. I am really happy that iBasso went this way because my previous experience with semi-customs were really great. Let’s talk about build quality. IT03 is a 2-piece design. IT03 features hardened acrylic shell, metal mesh nozzle and flush MMCX sockets. Build quality is good but there are little dents on the metal mesh. Nothing serious. IEMs feel durable and sturdy. Fit is also good, I can wear them without irritation for long period of time.

Sound Signature

IT03 can be classified as V-shaped. Highlighted treble and bass response, recessed midrange and neutral signature can be said to cover IT03’s signature except the bass region. Dynamic driver adds some warmth to the equation but IT03’s aggressive treble equalizes the scales.



This is the tricky part. You’ll have to try many tips because they change the bass response dramatically. I found my perfect spot with JVC Spiral Dots. Bass is big, punchy and powerful. I often found myself listening to old deep house tracks with the IT03. Let’s go lower. Sub-bass rumble is satisfying in most cases and we Hans Zimmer’d the IT03, experienced no sub-bass shortages along the way.  IT03 had some trouble coping with fast twin pedal passages but overall experience was satisfactory. Mid-bass is kind, only here when the track asks for it. This contributes to overall airiness in a good way.



IT03 offers a mixed bag of treats when it comes to the midrange. Lower mids are light resulting in slimmer note thickness. You feel this the most with string instruments. This may be important if you’re coming from something like Westone UM30 or TG334. Although I must say, detail retrieval is very impressive for a 250$ IEM. Some vocals may sound “dry” but the V signature works in favor of IT03 in this regard. Upper mids. Well, this is where ‘schiit’ gets real. Source selection is everything when it comes to IT03. It has a volatile upper mid region. For example with Chord Hugo I’ve noticed peaks that can be classified as sibilance. However, with Centrance Dacportable, upper mids were smoother. Tamed. So yes, try to choose sources that has recessed upper mid region for the best balance.



Energetic. Crispy. Clear. High region of IT03 is good, certainly performs above its asking price. Extension is also good with plenty of details. Cymbal shimmers are bright and energetic. Listening to wind instruments feels great with IT03. Wrong source selection may result in aggressive, sticky highs and this can cause ear fatigue very quickly. So, if you’re not a treble junky, I recommend you to select your source accordingly.


Soundstage, Imaging & PRaT

IT03’s headroom is above average. Instrument separation and imaging is decent. Soundstage is depth oriented. Sadly, sense of location is often lost with fast paced track but when we consider its price tag, it’s good.


Specs: 6N Single Crystal Copper & Silver 8-Braid

Signature: Forward lows and highs. Classic hybrid cable signature. Detail retrieval is great and cable is very well built. Plugs are stiff and sturdy. Braiding and coating is great, CB12 is quite flexible. I am really blown away by iBasso’s cables to be honest. Both CB12 & CB13 is quite beautiful.

CB12 contributes to the airiness and increases the perceived soundstage. It also adds extra oomph to the bass region and tightens subbass. On top of all these, resolution stepped up a notch! For 89$ this is the very definition of “upgrade cable”.


Specs: 5N Mono Crystal Silver & 6N Mono Crystal Copper 8-Braid

Signature: Balanced. Excluding the price tag, I love everything about CB13. Build quality is amazing, from plugs to splitters. Coating is soft and cable is very flexible. It’s signature is balanced and it almost contributes to every aspect of the IEM. For IT03, it increases the resolution, coherency, musicality and clarity. It also neutralizes notorious peaks in the upper mid region. CB13 equipped IT03 deals with congestion more easily, therefore pushing the threshold of distortion. I have to say that these do apply to other earphones as well, I am currently using CB13 with Sony N3-AP and I am VERY satisfied with it!

MSRP: $199

Quick Comparison

vs. Westone UM30

UM30 is more emotional and its upper mid region is recessed compared to IT03. UM30’s highs are tamed whereas IT03’s wild. Soundstage wise they’re similar. Fatigue can be a problem if you’re switching from something like UM30 to IT03.

IT03’s resolution and clarity is superior.


vs. Earsonics ES-2

They are both clearly different in almost every way. ES-2 is a warm, dark, relaxing IEM whereas IT03 is energetic, more neutral, bright and V-shaped. Resolution wise IT03 is ahead. Dynamism-wise they’re almost equal. When it comes to soundstage and imaging, IT03 is airier whereas ES-2 is emotional. ES-2’s vocals are very forward and its treble is trimmed.



For the price, IT03 offers a good fit, a fun signature, great level of clarity and solid, punchy low end with a equally highlighted treble response. Do not forget that selection of source is vital!


Author Aero

Tech Enthusiast, Audiophile, Perfectionist.

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