I've taken the liberty to edit and clean up your article. Rather uneventful holiday today
Introduction
The AK Custom 3+1, as its name suggests, contains 3 BA drivers in tandem with a single dynamic driver. The overall aesthetic is nothing special and rather minimalistic at first glance.
However, the shells are fully acrylic and the build quality matches that of high end IEMs. The packaging is simple, coming in a plain brown box with some additional rubber tips.
Significant qualities
The sound is very impressive and very close to my own personal preferences. Very balanced sounding with nothing sounding out of place in its frequency response.
Sound Quality
Midrange & Treble
The midrange is very clean and clear with forward-sounding vocals. Because of this, live, concert and "unplugged" variants of songs are preferred on this IEM.
The detail and the texture from the 3 BA drivers are the best parts of the sound signature, remaining consistent throughout its frequency response.
Treble is good too; at the beginning I was not a fan of its treble due to its peakiness and sibilance. After some listening with the AK 3+1, I realized that the treble was instead perfectly done, balancing its smoothness and sparkle nicely.
Bass
Bass is very well done; I have never had other IEMs that can do bass as tight as the AK 3+1.
Bass is a rather expensive[COLOR=FF0000](?)[/COLOR] quality to have, being similar in quantity and quality as the AK 2+1.[COLOR=FF0000]("Bass is a expensive parts, cause even expensive can't archived that same amount of bass than AK 2+1 & 3+1.")[/COLOR]
Soundstaging
The AK 3+1 has a very deep, huge and wide soundstaging, resulting in very good 3D imaging.
The best thing is that there is no distortion at all, performing solidly in every single track that I've thrown at it.
Fit, comfort and cable
The fit is nice and relaxing with no complaints about its weight. With foam tips, the seal is much improved, resulting in better isolation.
Stock cable quality is good. [COLOR=FF0000]("can feels that better bass quality as well" < what is this in reference to?)[/COLOR]
The AK 3+1 comes with the MMCX connector option only, while the AK 2+1 comes with the traditional 2-pin socket.
Comparisons
In comparison to the AK 2+1, the AK 3+1 is better textured in the mids and treble and has better soundstage. Bass-wise, both are more or less on par with one another.
The **** 4in1 is better sounding overall than the AK 2+1[COLOR=FF0000](?)[/COLOR] but is harder to drive, requiring a higher volume that the 3+1. The mids and treble are similar to IEMs that use single BA drivers.
However, compared to the 3+1, it wasn't as good, though it is definitely better than other IEMs in its price range. I would love it if it had at least 80% of the soundstage of the 3+1.
The best thing about the 4in1 is its tight bass too, though do make sure to use foam tips to help with the fit. Weight is also a much bigger issue on the 4in1.
The UM Martian is a great sounding IEM, though it can't deliver the same sweet quality in the AK 3+1's sound. Bass-wise, despite the Martian's dual dynamic system, the bass quality is still disappointingly not up to the standard of the 3+1.
The Campfire Audio Andromeda and the Jupiter can't really compare to the AK since they are in a completely different league altogether.
The DQSM D2 has a very good overall sound, but there is a slight distortion in the mid-bass. The mids also easily overlap with the treble due to the richness of the overall sound and relative hotness of the treble.
The RHA T20i would be a nice sounding and basshead IEM as well, performing well in soundstage very comparable to the AK 2+1 and 3+1. It's jus that the T20i is missing something in its recessed midrange, else it'll be in my IEM collection too.
Conclusion
There is nothing like the AK 3+1. [COLOR=FF0000]("sounds was superior already, the rest out of my hand, has never beats with these")[/COLOR]
You'd only understand once you'd personally experienced what this IEM has to offer.
Its impedance is 16 ohms only, making it easy to drive off an iDevice at 50-60% volume.
Songs used:
The AK 3+1 performs well with the Coldplay track "Every Teardrop is A Waterfall".
The experience was good, whatever instrumental separation and laying that the CA Jupiter can achieve can be done on the AK 3+1.
With the single dynamic driver, the song feels very clustered and busy. The D2, 4in1 & Rose no7 can't do that well as AK's BA drivers.
[COLOR=FF0000]Highlighted in red are some things I can't decipher, so do clarify.[/COLOR]