[DaemonSire]

  Just got my HE-400i's today! Was going to get it on the black friday sale but ended up picking one of the older ones with a norne mini-xlr adapter. I have a set of Vero mini-xlr reference cables coming in which will be perfect for these, so things worked out well =) These things look super sexy, light and comfy. I think if you happen to have one of the older cable screw in types you should definitely pick up the norne adapter.
 

 
 
Some sound impressions: (warning: I've got a bit of synesthesia so my descriptions might make me sound like a crazy person...)
 
I should note that i previously had a pair of HE 560s and modded LCD 2.2, and tested LCD XC & LCD3Fs for two weeks (sold my LCD2.2 to save for LCD3), I also had the Mad dog 3.2s, just haven't time with the Oppos. These crush the Mad Dogs, are in the league of the 560 and LCD2.2 (LCD3F and XCs are a whole nother level).
 
When compared to the HE560s & LCD 2.2 from memory out of a gustard H10 (also note i've now updated my setup with Burson V5 opamps), these have a veeery nice clarity fluidity to it, but not as rich as the LCDs or top glossy/sparkly like the HE560s. The LCD2.2 was like rich darker toffee caramel, lush and swirly, the HE560 was like sweet light amber caramel candy that's top sparkly and glossy sweetness. 
 
The He-400i on the other hand is got a nice slight cooler clear glossy flavor. its still got that sweetness, but less caramel, more liquid ice. like ice in a martini glass or scotch (depending on the music you listen to). It has a very nice breath of fresh morning frost air, though with its soundstage making it very intimate (like instead of being in a open field, you're in a roofless 1 story spanish-mission-styled house without doors), and i think if mods are performed to open it up it would be even better.
 
Overall i reaally dig these. i think they're definitely more balanced sounding than the HE 560s. From memory i think i like these better actually. LCDs have better lush / richness and breathtaking vocals when amped right (gustard H10), but im going to get LCD3s for that. (plus LCDs are way to heavy for casual long term listening). Compared to the LCDs these do have better clarity / crispness, while keeping fluidity without being dry (think of DT880s, which i have and love, but are dry / thin / whispier) 
 
So yeah. with all that, absolutely worth the money. at $300 its a no-brainer, you must get it. At $500 its a fantastic buy still, definitely a better buy than the 560s in my opinion (which i did like, but bang for buck the 400i is a better deal). law of diminishing returns definitely applies.

 
Do you find the adapter makes the cable end long and hit the shoulders?  Since HFM do not use angled connectors, it looks like it might get in the way?
 
I've thought about getting those in the past because I have an Audeze cable I would like to use on HFM but that part always worried me.

 

[ChesterYonany]

   
The word that keeps coming to mind with this pair is simply "effortless" They just effortlessly bring me my music.  They get out of the way.
 
one other point is this has by far the most listenable range of volume I've ever heard.  On the Grace, I find them listenable from 59 to 77.  That's almost 20 dB of difference that I find them perfectly listenable.

i agree with everything you said but this like says it all really.
 
i also think that the 400i isnt changing its characterizes when you change volume, its just louder and somehow "better"
 
string instruments and drums sound special on the 400i.

 

[bavinck]

  I think the HE400i paired with the Grace m9XX could be my endgame setup.  As they've both rolled past 150 hours, with 80 hours of "on head" time, this is just such an incredible pairing.  
 
I finally have the headband bent/stretched *just right*. They were never uncomfortable, even straight out of the box, but there was a tiny bit of pressure, now they're firmly in the "can melt off the head" feeling during long sessions.  And these are the *perfect* pairing for long sessions.  Enabling crossfeed on the Grace, and this is the least fatiguing headphone I've ever heard.  The resolution and transparency means that I never have to strain to hear anything.  The tonal balance, flat bass and  (to me) neutrality means no frequency ever wears you out. The crossfeed makes for a less fatiguing listen as well.  While the soundstage isn't vast, it's so coherent and imaging is so precise, that it's an effortless listen.  It's present without being sibilant.  The bass is full and extends, without booming (which can get fatiguing after a while to me).  
 
The signature, right away, seems maybe kind of boring, especially coming from the THX00.  But it's just so resolving, transparent and fast, while being smooth and musical, that those qualities become fun in their own right.  I realize instead of being like "wow, oh my god the bass" like I am with the THX00, more often I think "wow, this song is incredible.  WIth this can it just becomes so squarely about the music as opposed to noticing things about the headphone.  With things like the THX00, TH900, HD800, LCD2, RS1, etc I always felt like a large part of me was listening to the headphone instead of the music.  Here I just feel like I'm listening to the music.  
 
The word that keeps coming to mind with this pair is simply "effortless" They just effortlessly bring me my music.  They get out of the way.
 
edit: one other point is this has by far the most listenable range of volume I've ever heard.  On the Grace, I find them listenable from 59 to 77.  That's almost 20 dB of difference that I find them perfectly listenable.  

Yes!
 
In addition, the timbre of the he400i constantly blows me away. Piano (hard to reproduce right) sounds right, drums and cymbols sound right. Everything sounds as it should. Today I plugged it directly into my note 3 ho, it sounds almost as good as through a nice dac/amp, I could listen to it like that for a long time and not really feel like I am missing out on what this headphone could do. That is amazing. I also think the 400i is end game for me. I also have the x00 coming, but it is more for fun and it is closed so I am hoping it is portable.

 

[fjrabon]

  Yes!
 
In addition, the timbre of the he400i constantly blows me away. Piano (hard to reproduce right) sounds right, drums and cymbols sound right. Everything sounds as it should. Today I plugged it directly into my note 3 ho, it sounds almost as good as through a nice dac/amp, I could listen to it like that for a long time and not really feel like I am missing out on what this headphone could do. That is amazing. I also think the 400i is end game for me. I also have the x00 coming, but it is more for fun and it is closed so I am hoping it is portable.

oh, yeah.  I play it straight out of my iPhone all the time while doing chores around the house, or even sometimes when walking the dog (going down the more quiet streets obviously).  It sounds great straight of my iphone.  About six months ago, I decided that I wanted my setup such that it fit these requirements:
 
1) Must sound great straight out of an iPhone.  I will never buy another headphone again that I can't enjoy straight out of my phone.  Too much of my listening time is straight out of an iPhone for me to not be able to enjoy a headphone that way.  Doesn't matter how mindblowing the *perfect* setup on it is, if it's not great out of an iPhone too, I'm passing.
2) Can't be a "one trick pony" that I only enjoy certain genres of music for.  If I can't enjoy the entire spectrum of music I listen to on it, I'm passing, no matter how mindblowing it makes certain genres.
3) Can't be uncomfortable.  This is for enjoyment for me, it's supposed to be comforting and relaxing.  (gave my SR225e to a friend for her christmas present last night, btw).
4) Can't be fatiguing.  No matter how technically capable, and how fun it is on immediate listen, it can't be fatiguing for long sessions.
 
The HE400i knocks all of these out of the park.  I'm honestly shocked how little I've had to compromise on overall sound quality, given those 4 requirements.  And saved a boatload of cash.  Really, the only headphone I'm even slightly intrigued by is the HE-X.  I guess I'll get to listen to Matt's in January (assuming he hasn't flipped it by then, haha).
The only thing that's ever come close to this pairing for me was:
HD650 (paid $440)
Bitfrost ($399)
Lyr ($529)
For a total of $1370.
I honestly like the Grace + HE400i slightly better than that setup, and it fits in a messenger bag and cost $570 less.  And the HD650 was more or less useless out of an iPhone.

 

[mysticstryk]

Sounds like you've got your perfect synergy setup we all strive for!

 

[Noodlz]

@DaemonSire actually the cables are fine, when i wear them the cables are pointed forward slightly, just enough so it doesn't get in the way. that being said, with the adapter it does make it a little more difficult to put it on a headphone stand if its not tall enough. (i managed to put it on my main stand still, see below)
 

 
@fjrabon sounds like this thing pairs really well with the M9xx, i still have to try out that out, maybe on the next drop. Either that or get the chord Mojo. I'm currently using Centrance Hifi m8 as my portable setup. The 400i sounds great out of an iphone, better still on the M8, but in full effect when using my H10 (soundstage / air / fluid light crisp sweetness etc)

 

[blacknwhite]

Hi
 
It’s upgrading time again and I’m considering the hifiman he 400i’s as a companion can for my sennheiser hd 700.  Are there many aspects of this headphone that surpass the hd 700? I’m mainly looking for a can with great bass and hopefully faster decay than my hd 700’s, if these are it, please let me know.
 
Also, I’m open to any other suggestions in the price range of 300-600€ open or closed back. I’m hoping for a planar though since they always get great reviews about their bass. I’m not particularly a basshead, but do enjoy a fair bit of edm, r&b, etc… and here is where I think I would benefit from owning 2 totally different headphones.
 
I mainly use my hd 700 for classical, jazz, blues, etc… and hope the he 400i will complement my other music.
 
Any input is greatly appreciated.
 
cheers

 

[Sonic Defender]

^ The 400i is certainly fast, and I think it has very good bass and I have owned a D7000 and TH 900. I have not heard the HD 700 (owned an HD 650) but regardless, the 400i is fast and has some pretty solid bass capabilities no doubt about it. In terms of bass quantity it is somewhat better than the HE 560 which I also owned, but the bass quality on the HE 560 would be better, but not significantly so. For the price the 400i is pretty darn good in my books.

 

[titaniumx3]

Are there different versions of the 400i? I know there's a newer version with the new 2.5mm connectors, but does it sound different?

 

[bavinck]

Are there different versions of the 400i? I know there's a newer version with the new 2.5mm connectors, but does it sound different?

Same sound, different connectors.

 

[Mr Rick]

Same sound, different connectors.

What? You don't believe in the sonic differences of connectors ? 

 

[bavinck]

  What? You don't believe in the sonic differences of connectors ? 

Ya, not so much, sorry to be an unbeliever,,,,

 

[bavinck]

Now my next job is to find a closed back headphone with excellent isolation that sounds like the he400i and has similar amping requirements. Any idea? Oppo pm3? Ether?

 

[Semont]

   
Do you find the adapter makes the cable end long and hit the shoulders?  Since HFM do not use angled connectors, it looks like it might get in the way?
 
I've thought about getting those in the past because I have an Audeze cable I would like to use on HFM but that part always worried me.

 
The connectors are angled so it's not a problem.

 

[swspiers]

Now my next job is to find a closed back headphone with excellent isolation that sounds like the he400i and has similar amping requirements. Any idea? Oppo pm3? Ether?

Awesome question!