Let me start with some preliminary remarks.
I am a se846 user for more than 2,5 years and after having tried different portable source pairings (e.g. LG V30, Fiio M11, Nextdrive Spectra) I ended up having them on a Shure BT2 adapter. The performance was very good but not what I expected from 800 euro IEM. I recently put them on sale with the thought of trying an CA Andromeda or a Solaris instead.
Two months ago I bought a Chord Mojo and plugged them in after I've made the blue filter mod. That completely changed my opinion about them, even though the high treble roll-off was still a minor issue, the resolution and musicality of the rest of the range just blew me away. This combination gave that 15% boost in performance that makes these babies truly shine. I should've known better.
So it is upon this critical background that I came to be listening to the Aonic 4 these last few days and it is understandably an unfair comparison.
Starting from an interchanging A/B session using the twin outputs of the Mojo (see picture- plugged to a laptop with Audirvana studio) one is stricken from a notable difference in clarity of the midrange and high frequencies. Compared to the sheer presence of the different acoustic items in the headspace in the case of the se846s, the Aonic 4s have a veiled, lay-back presentation.
Regardless of the frequency graphs which represent similar sub-bass amount for the two (well the se846 are represented to have a bit steeper ascent in that area -https://crinacle.com/graphs/iems/shure-aonic-4/ ,
https://crinacle.com/graphs/iems/shure-se846/) and a 1-2db boost in the high-treble, the Aonic 4s have a mid-bass expression and the highs sound over all distant and quite muffled in comparison. That is something that I actually did not expect especially for the highs. It would seem to someone that the mids would be recessed due to the difference in technicalities but at least the treble would be clear enough with at least some amount of shimmer.
But this is not the case. For example, Baby Interface from the album Microgravity by Biosphere (
https://tidal.com/browse/track/4167371) is an electronica track that covers in a distinct fashion all the FR and which I often use for testing headphones. With the se846, the bass is clear and sturdy, the midrange items clean and attacking holographically around your headspace. The treble is pristine and unfatiguing (while my Sennheisers Ie400pro have even richer highs but while quite controlled they sometimes do get tiring).
Changing now to the Aonic 4s, the bass is good but midbass-centered and less in amount, the sub-bass is effectively produced when present in the production (listen to the subtle change towards the sub-region at 1:51 of the track mentioned above). The mids sound as if coming from some distance, and the highs veiled and discernibly less in resolution. This is the case with other genres I tested them with. Even though the have 7ohm impedance the se846 are less louder and turning the loudness dial up does not bring those midrange elements in the fore but an annoying midbass peak instead.
I have to disagree with Garreth83 about the aggressiveness of Aonic 4s. They actually sound quite laid-back to me, at least comparing to the se846s. They have an even presentation and they don't attempt to impress with any frequency region. The soundstage is not more extended than se846 and certainly not an expansive one as others have claimed. They offer a decent rendering of different genres, they are unfatiguing if not a bit dull.
As I mentioned above it is unfair to compare them to the top dog of the SE line. The se846 beat them in almost every respect. But I have to give them the credit for not allowing them much burn-in (either objective or brain-wise) that is why I now have them plugged on the Shure BT2 adapter for some more long-term casual listen. They actually are not a bad IEM. They are good sounding, great looking and ultra-comfortable. But in the end of the day I am considering returning them to amazon if a few days' listen does not change my mind.
