Mm.initial impressions. I've longed to own an Ocharaku for the past 2 years (because of a few positive reviews, enough to capture my attention). As the Flat 4 Akakeyaki Plus is my first Ocharaku, I am not familiar with the Ocharaku house sound or tuning. For now, I can say that I am impressed with the SQ. It is one of the most comfortable in-ear I've ever worn. It feels like I am not wearing an in-ear. The powerful bass has impact and it is clearly defined but not overpowering. It does not bleed into the mids. The mids are well-behaved, very pleasant and natural sounding. The treble is very good but with the supplied Spinfit eartips, the treble has a lot of energy. I can hear some unpleasant sibilance. With the supplied Comply eartips, the sibilance is attenuated (reduced to next to nothing). Overall, the Akekayaki Plus is a very musical in-ear without sacrificing detail retrieval. It sounds less an in-ear and more a headphone.
Favorite DAP pairing, so far, is with the Cayin N6.
http://ocharaku.jp/sound/service/