Before describing the sound of the IT04, let’s remember and understand how the IT03 sounds like. The previous model has a sub-bass focus and slightly laid back mid-bass region. In addition, the mids were slightly behind in the stage as well and they don’t have the best resolution.
The separation level is also not great, but it has a very controlled, coherent and unaggressive sound except the sub bass focus. The IT04 shares some of the characteristics of the IT03, but in some areas it obviously gives a higher level of performance.
The new iBasso IT04 sounds very well balanced and coherent throughout with a much better mid presentation overall. It’s resolving and clean with a slight warmness and musicality, and it technically is like an advanced version of the IT03.
Lows are more refined with the IT04 when compared to the IT03. The sub-bass emphasis and intensity isn’t there anymore. There’s more room for mid-bass this time, and together with the adequate sub-bass presence they both create a very nice bass body. The bass is under control and the separation from the mid area is very good.
There’s not much rumble but it has good kick with its lows. They’re also quite fast, therefore the decay is very good. Maybe the IT03 has more rumble and punch down low, but it doesn’t have a tight bass presentation like this one. As a result, the overall quality of the bass region is much better with the IT04.
In short, you get less bass quantity but with much better quality, which is key for an IEM that is intended to perform on a higher level.
The mid region is not in front, it instead is slightly behind, but not so much like the IT03. Thanks to the significant improvement in the bass department, mids are cleaner and they have more space to shine. Therefore they’re more accentuated then the IT03 model, hence you have a better instrumental performance. The vocals are also crisper and they can shine more this time around.
The tonal accuracy is good, but not great. That’s not unexpected though when you consider the price level. I also would prefer a bigger note size with more body in mids to have a fuller and richer presentation. It presents lighter notes than I would like to have, yet it’s still very good as it is nevertheless, especially when you consider the other 500$ options in the market.
The IEM has a very good background blackness, and the mids are more resolving then in the predecessor. That creates a much more satisfying mid performance with good musicality and dynamism. The IT04 is more lively, clean and sharp with good energy.
Just like the overall presentation, the IT04’s treble is a balanced-out version of the IT03. Although that lower treble emphasis is still slightly present, it has a better and lifted upper treble performance when compared. That forms a truer and more coherent treble presentation, and contributes to a better overall balance in the whole spectrum.
It copes with high volume levels as well, as I didn’t hear obvious peaks with the many tracks I’ve listened to. Maybe if you crank the volume up too much you can hear some peaks at lower treble but that’s pretty much unlikely, unless you want to get your ears in trouble. The overall extension is not the best I’ve heard of course, but since it also is an improved area after the IT03, I can’t complain.
Technically the iBasso IT04 is a very competent IEM. The overall resolution is one of the best I’ve heard in this price range, and the separation is very very nice. It is a highly resolving earphone and I think it is a very important achievement after the IT03. Transparency level is very good and it layers the sound pretty well.
Sound stage is nice, but not very wide and deep. It instead plays quite close, like you’re in the front row of a concert hall. That gives the IEM a very nice energy and dynamism though. It’s never boring, never too reserved or laid back. The good thing is that it also isn’t aggressive while doing that. The overall magnitude of the sound stage is ideal for both width and depth, but it’s not very big. Yet, I think it’s not behind any of its competitors regarding that. After all, you probably need to pay double the price to get that big sound stage performance.
The background is blacker than the predecessor‘s and also than many IEMs out there. The notes come out quite sharp with good attack from that blackness, but not with a lush presence that I would like to have. Still, it has a good musicality and note size & thickness for this price. Of course you can change that with different cable experiments.