iBasso IT04
Headfonics 2018

iBasso IT04 Review

The iBasso IT04 is the company’s new flagship hybrid universal IEM consisting of 3 balanced armature drivers and one single dynamic driver priced at $499.

Disclaimer: The iBasso IT04 was sent to us in exchange for our honest opinion. Thank you to iBasso for giving us this opportunity.

To read more about iBasso products we have reviewed you can click here.

Note, this review follows our new scoring guidelines for 2020 which you can read up on here.

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Whilst not as prolific as some of their counterparts, iBasso has been slowly building an impressive portfolio of in-ear monitors over the last few years. The IT03 triple-hybrid driver IEM kicked things off two years ago and got a lot of attention, not least for its price to performance ratio.

We also reviewed the entry-level single dynamic driver IT01 earlier this year and again the outcome was somewhat similar, a solid IEM for the price. Now we have iBasso’s most ambitious entry to date, the IT04. This is a hybrid quad-driver universal monitor priced at $499.

It is also their flagship IEM with a new sound signature but also retaining some legacy features that were first rolled out in their previous product launches.

This is no longer budget, this is a mid to high point offering or “mid-fi” for want of a better meme. Will it appeal to a new more discerning audience? Will it tempt iBasso’s existing loyal followers to come along on a merry upgrade? We shall see!

Technology Inside

Dynamic Driver

Well, I did mention legacy features and yes, it does borrow from a mix of existing technology from the current lineup to serve as the building blocks for the IT04.

First, there is the impressive 10mm dynamic driver of the IT01 with its multi-layered graphene diaphragm. This is a small mass density, light and thin design for low distortion and quick transients. It also retains the 1 Tesla magnetic flux strength to enable enhanced performance at loud levels.

iBasso IT04

Custom Universal

The second legacy feature is plucked from the IT03 in part and continued with the IT01. The term I like to apply to this feature is the “custom” universal shell design. The IT03 was perhaps the first to really bring this concept of a highly customized shape to perfectly fit in the ear of most people and the IT04 has made use of that design philosophy also. This should mean a very high comfort level and a great seal.

Balance Armature Set-up

iBasso has also chosen Knowles’ TWFK-30017 and ED drivers to complete the internal quad-driver design of the IT04. I believe the 30017 driver is the same model used inside the IT03 though in a different configuration.

The BA configuration for the IT04 is 1 Knowles full-range ED driver and the 30017 dual-driver. The 30017 is technically 2 drivers so one driver is for the lower treble and one for the upper treble with the ED driver for the mids.

These ‘single-bore dual-driver’ models are getting quite popular now with both SIMGOT and FiiO using them in mid-fi and entry-level hybrid offerings such as the EM3 and F9 Pro. Their performance is entirely down to the desired tuning and can sound refined and clean or harsh depending on far you push them.

iBasso IT04

Build Quality

Tighter Curves

From a distance, the reflective black IT04 shell looks the same as the IT03 save for a reworking of the front faceplate. But on closer inspection, iBasso have really tightened up their “custom” contouring of the main body. The curving to the rear is much more defined with the recessed dip that rides the crus of the helix even deeper than before.

The front of the shell is straighter than the IT03 with a much longer nozzle. The Nozzle is also further forward and higher up than the IT03 version with a wider opening and a protective wire gauze finish. The lip of the nozzle is also much further down as a result of the additional length. It is also kind of well, too polite in grip on some of the tips which I will get into later.

The body sides to the fore are also a little deeper to accommodate the new MMCX connectors that replace the older IT03 2-pin jacks. The MMCX is also a millimeter or two more central than the older 2-pin jacks.

Face Plate

The IT04 faceplate is a big improvement simply because the IT03 never really had a faceplate. The IT03 was really just a black shell with a smooth black plate surface and the logo printed. The IT04, on the other hand, uses a 4K blue-black mixed carbon fiber panel which creates a really nice holographic shimmer.

This panel is also quite deep-set which I intensely prefer on custom designs to shallow plates. It looks far more seamless once the top is polished and given its reflective coating. Front and center on the face plate is the “InTune” branding in silver which really enhances that 3D like quality.

iBasso IT04

Cables & Connectors


iBasso have switched to an MMCX connection system this time around with the IT04. This makes a lot of sense since their subsequent CB12 and CB13 cables all come with MMCX connectors. These are clean circular shaped rather than the flat-plate version though they will accommodate all MMCX connectors on the market bar the most obstinately shaped.


And of course, iBasso did include a CB cable as stock with the IT04, the CB12s. The CB12s is a slightly updated version of the original CB12 cable. This is an 8-wire SPC and copper wire in a very pliable translucent jacket. You also get no memory hooks with the finish but they are heavy enough to easily around your ear (over the ear fit).

You can make out the SPC and copper wiring in the braided weave quite easily with a nice contrast between the silver and copper tones overlaying each other. This is a very microphonic-free cable, very easy to work with and contains almost no memory retention.


The cable is terminated with a 2.5mm balanced jack with matching aluminum barrels for both connectors and the y-split and chin cinch. The CB12s also comes with a piggy-tail connector for 2.5mm connectors which looks like an updated version of their CA01. This is the same wire, same barrels, same everything. A very useful addition for those that prefer unbalanced or have no balanced connections.

The 2.5mm balanced stock termination will also allow you to throw on a 4.4mm jack converter for iBasso AMP8 cards, Sony DAPs or the new Oriolus B300s 4.4mm balanced portable amp.

iBasso IT04

Comfort & Fit

The comfort and fit on the IT04 are just perfect, it really is. In fact, I think they managed to improve a little on the IT03 which impressed me greatly, to begin with.

The difference is really the outwards pressure on the Antihelix or the inner semi-circular ridge of your ear. The IT03 exerts a little more pressure around that ridge whereas the IT04 reduces it and places a little more emphasis on the deeper nozzle holding things in place along with the tip.


Because of the additional length of the nozzle, the tip plays a slightly greater role for me on the IT04 than the IT03. Thankfully iBasso has supplied a huge range of tips to choose from, possibly the largest collection on any universal I have seen to date.

Inside you get no less than 6 bags of tips, 5 of them silicone (S/M/L) in varying depths and bore sizes and a single set of foam tips in both medium and large size. You also get an additional set out of single bore silicone tips on the IT04 out of the box.

Tip Preferences

Moving around the tips I tended to find those tips with a narrow longer bore where a bit lighter in sound than the wide bore tips which delivered a bit more body and range. The only issue was the lip. Since the nozzle goes in deeper more of the tip is being worked into my ear which creates some friction. I found the supple silicone wide bore tips to slide off a lot on the way out. It was less of an issue with the narrow bore tips which had a tighter stem but I was less keen on their presentation.

The best compromise was the foam tip. I had the best seal out of the three from the foams, the best low-end body and they stayed pretty tight on the nozzle. I ended up using the foam tips for the remainder of the review.

iBasso IT04

Accessories & Packaging

The packaging is in the same ballpark as the IT01 but a grade or two higher in quality. You get the same lid design box but bi-folding rather than the flip design of the IT01. The IT04’s are neatly tucked away in the aluminum screw lid carry case in a nice little corduroy insert. To the bottom, you have an accessories box with the cables and ear tips and to the side a little manuals envelope.

iBasso IT04

I have to give props for the little corduroy insert. It is actually something I would not pack away with the box and probably use on the go along with the aluminum case. It holds them neatly in one place for display and prevents from knocks and bangs. If you want more to pack in the case it will have to come out though. The bottom and top of the case are fabric lined though so it does have a decent level of protection.


Click on Page 2 for Sound Impressions & Comparisons

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