I analyzed N6ii sound using various earphones/headphones, such as U18t, Solaris, T5p 2nd gen, and Empyrean while playing a variety of my favorite test tracks, such as Agnes Obel “The curse”, Sandro Cavazza “So much better” (Avicii remix), C-Bool “Never go away”, Ariana Grande “Break up with your girlfriend”, Ed Sheeran “Shape of you”, Galantis “Hunter”, Iggy Azalea “Black widow”, Indila “Boite en argent”, Robin Schultz “Oh child”, David Elias “Vision of her”, and Michael Jackson “Dirty Diana”.
Please keep in mind, the sound I’m describing below is how I hear my specific earphones and headphones paired up with N6ii during the testing.
I did collect sound impressions straight out of the box, then after about 3 days of continuous playback, and later after a few more days while running battery tests. I usually don’t preach about “burn in” effect and respect whatever people believe in, but based on my personal experience with N6ii I noticed the sound changing from more neutral to slightly warmer, getting fuller and more organic in body with treble taming down. Throughout this listening process, I was going back’n’forth with a few other DAPs, using them as my point of comparison reference.
Using IEMs/headphones mentioned above, I’m hearing N6ii as having a smoother tonality with a fuller body, especially in lower mids, and a less aggressive, more natural musical sound. It has a deeper, slightly elevated bass response which is a bit relaxed with a slower attack, natural more organic mids, and also smoother and more natural treble. In comparison to a number of other DAPs, the extra body in lower mids and tamer treble sparkle was quite noticeable, giving N6ii a more natural tonality even with a few of the songs where I typically hear a brighter leaner sound. As a result, instruments and vocals have a rich natural timbre.
It has a pretty good dynamics (vertical expansion of the sound), but I hear slightly less air between the layers since treble is more natural (less sparkly). Also, I hear a clean transient response of the note on/off transition from the black background, but the speed of how fast details pop out of the blackness was a little more relaxed, perhaps even a bit laidback. I spent quite some time comparing it to other DAPs, and I hear the sound of N6ii to be less aggressive, a little more relaxed, more analog, less digital.
The soundstage is wide, but not exaggerated. It’s not the widest I heard, and that of course will depend on earphones/headphones, recording material, your hearing, etc. But it was on par with many other flagships, having a natural realistic width and relatively accurate imaging with convincing placement of instruments and vocals. Of course, as already mentioned, a lot of this will be dictated by technical performance of your earphones and headphones, but I wanted to mention that N6ii as a source shouldn’t be a limiting factor here.
After the recent v1.15 fw update, I hear the sound to be nearly the same, just with a touch more transparency in mids which creates a slightly brighter perception of the sound. Obviously, I can’t do a real time side-by-side a/b comparison.
Regardless if you are planning to use it with IEMs or full size headphones, I found N6ii to pair up well with almost everything.
64 Audio U18t – wide expanded soundstage with an average depth, bringing you a little closer to the stage. Punchy fast bass, very articulate, layered, and well controlled. Neutral lower mids with a touch of extra body to give the sound a more natural tonality. Clear, detailed upper mids/vocals with a more revealing characteristics, but not too bright. Crisp well controlled extended treble without any harsh lower treble peaks.
64 Audio Fourte Noir – very wide soundstage with a more intimate depth, bringing vocals closer to you. Bass has a deep extension with a meaty sub-bass rumble, and mid-bass has a strong slightly elevated punch, overall bass slams hard here. Lower mids are thicker, with a fuller body, giving the sound and the vocals a more natural organic tonality. Upper mids are clear and detailed, not as revealing, but more natural. Treble is crisp, well controlled, natural without any harsh peaks.
Campfire Audio Andromeda – wide soundstage expansion with a little more out-of-your-head depth. Bass is a little laid back with a slower attack and a bit longer decay, more typical of DD performance, but still with a decent control with nothing spilling into lower mids. Lower mids a little on a thicker fuller body side, but not congested or muddy, instead giving a more natural laidback tonality to mids. Upper mids are clear, detailed, also more organic, smoother. Treble is well controlled, with a nice sparkle, not too crisp, no harsh peaks, detected zero sibilance in lower treble. When idling or at a very low volume level, I do hear some “waterfall” hissing, typical of lower sensitivity Andro performance, but when volume is raised, it’s not audible.
Campfire Audio Solaris – very wide soundstage with a great depth, giving the sound a more holographic soundstage expansion. Bass goes low with a deep rumble and hits hard with a punchy fast mid-bass. Bass is well controlled, articulate, nicely layered. Lower mids are closer to neutral, though they do have a little more body, giving the sound a natural organic detailed tonality. Upper mids have great retrieval of details, not analytical, but quite revealing in a natural way. Treble is crisp, airy, and with a nice sparkle, but not harsh or spikey; no traces of sibilance was found. Really enjoyed this pair up, Solaris really shines here with a natural resolving sound, serious analog bass slam, and crisp treble details. When idling or at a very low volume level, the “waterfall” hissing level is stronger than Andro, but hardly noticeable with volume up.
Empire Ears Legend X – wide soundstage expansion with an average depth. Bass slams very hard in this pair up, goes deep, and mid-bass hits hard, making the bass a bit overwhelming, booming, and not as well controlled; would definitely benefit from some trimming with EQ. Lower mids are warm and on a thicker side, a bit overshadowed by the booming bass. Upper mids are pushed more back, natural and detailed, but you need to shift your focus away from the bass to hear vocals better. Treble is crisp and well defined, comes through crystal clear, and along with the bass gives LX a more v-shaped signature. I wasn’t too crazy about this pair up, but that’s my personal bias since I find LX bass a bit overwhelming for my taste, and N6ii sound sig enhances its slam even more.
Sennheiser IE800s – wide soundstage expansion with more out of your head depth. Overall sound is more v-shaped with a smoother less aggressive bass which goes deep with a noticeable rumble and has a laid back slower mid-bass punch. Lower mids are north of neutral, with a fuller body, but nothing muddy or congested. Upper mids/vocals are clear, natural, more on a revealing side, but unfortunately pushed a little more back, especially with more staging depth which pushes them further in space. Treble is crisp, airy, snappy, not harsh but still with crisp details.
Beyerdynamic T5p 2nd gen – wide soundstage expansion with more depth in this pair up. Bass has a deep low-end extension but closer to neutral rumble, and mid-bass is fast and punchy; don’t recall bass of T5p2 being that fast in other pair ups. Lower mids are closer to neutral, with a nice touch of natural body, and upper mids/vocals are clear, detailed, on a brighter more revealing side. Treble is bright and crisp, very revealing, with a few peaks that can get harsh in poorly recorded song. Overall sound was a bit brighter than I expected.
Meze Empyrean – wide open soundstage with more out of your head depth. Great low-end extension with a slightly north of neutral rumble and a fast well controlled mid-bass punch. Bass is very nicely layered and quite articulate. Lower mids are closer to neutral, maintaining a natural body with upper mids/vocals being also natural, layered, with a great retrieval of details. Treble is crisp, airy, extended, well controlled, without any offending peaks. The overall sound is well balanced, natural, open, and quite resolving.