[drwlf]

  thin sound?  crap. please tell me more about it.  I was going to order them tomorrow.
If they are thin sounding, then no way im buying them. 

Depends on your reference point, and I really don't want to sound too negative, but basically they lack some body and heft in how they portray the sound, especially low/mid-departmentwise. The general sound is a bit on the thinner side of cans.
The slam isn't there, although it's often missing from planars. Impact isn't the same as dynamic drivers, but I guess that's kind of out the question tech-wise, but then again punchiness is enhanced due to the almost unnatural impulse response, and the 400i is certainly snappy.
It's a fine can for the money, and just superb for some genres, it does a lot of things well.
The bass response is closer to neutral, it extends very deep without significant roll-off, the bass doesn't bleed into the mids and the areas don't feel unnaturally separated. There's a lot of detail there, and they resolve well. In whole, the 400i are exciting, albeit rather analytical, but not in a dry, clinical sense.
It doesn't make much sense to compare them to my LCD-X, but that's one other reference point of mine; where the slam has these face-melting qualities. Probably the first thing you think after A/Bing them, is that the 400i sounds anemic in comparison. That's what I kind of mean.

 

[InsTwin]

I've been switching back and forth between a THX00 Mahogany and the HE400i.  I really appreciate the HE400i, the sound might be "thin" at first, but I would give it some time and also turn up the volume (maybe turn on high gain?).  I've found the sound to simply be superb for any electronic music (which is what I mainly listen to while working), old Metallica albums I've been listening to again recently.  I primarily listen to them at my desk from a Modi Multibit into a Magni 2Uber.
 
The album that really opened my eyes to these cans was XXYYXX's self titled album, XXYYXX.
 
I've found them not great for gaming or movies, they're fine but the K7XX is vastly superior to me.  Speed and detail are where these cans shine, and I can't get enough of how I perceive the bass to be textured.  Even though they don't slam, damn they sound good and the bass is just so pleasant.

 

[DavidA]

  thin sound?  crap. please tell me more about it.  I was going to order them tomorrow.
If they are thin sounding, then no way im buying them. 

 

 
I'd put them in the same sort of range as Grado's. I used RS1i's for a year or so. Grado's had a thicker midrange, but their highs were a bit more piercing than the Hifiman. 

I think the sound is not thin at all but it depends on what headphones you are used to, compared to the lower end Grado's I'd say they might be a little thin but not at all bad but if you are using HD650 or SRH-1840 then the HE400i will be thin sounding but if you were using Beyer DT-990 or T90 then the HE400i is not a thin sounding headphone, its all relative.
 
My SR225e (modded) is fuller sounding than the HE400i but even then I wouldn't consider either to be "full" sounding since my reference for full sounding is the HD650, EL8 or LCD-2.

 

[zerolight]

I was expecting something like a budget LCD2 out of these. What I did learn is that my Angies are awesome.

 

[xcom]

I was expecting something like a budget LCD2 out of these.

 
Way out.... You could have bought the Monolith M1060. Does are straight up LCD2 clones and are up there as far as sound. 
QC on the Monolith.... That's a whole different story. 

 

[sjwaudio]

  I've been switching back and forth between a THX00 Mahogany and the HE400i.  I really appreciate the HE400i, the sound might be "thin" at first, but I would give it some time and also turn up the volume (maybe turn on high gain?).  I've found the sound to simply be superb for any electronic music (which is what I mainly listen to while working), old Metallica albums I've been listening to again recently.  I primarily listen to them at my desk from a Modi Multibit into a Magni 2Uber.
 
The album that really opened my eyes to these cans was XXYYXX's self titled album, XXYYXX.
 
I've found them not great for gaming or movies, they're fine but the K7XX is vastly superior to me.  Speed and detail are where these cans shine, and I can't get enough of how I perceive the bass to be textured.  Even though they don't slam, damn they sound good and the bass is just so pleasant.

 
I heartily agree -- speed and detail are outstanding and addictive. I would not call them "thin" at all, but rather "neutral" and not adding anything to the bass that is not in the recording.
 
I use them primarily for acoustic music (mostly classical, with some folk, blues, and rock). They are usually the first headphone I reach for, although in regular rotation with Beyerdynamic DT880 (600 ohm), AKG K7XX/Q701, and Sennheiser HD650. Only the Beyer DT880 match them for detail. The DT880 and both AKGs (and the Senn HD650 if well amped) outshine them for soundstage, which matters a lot to me in acoustic music, but the HE400i's soundstage is still decent.
 
I don't find the HE400i to be as amp-dependent or amp-responsive as the DT880 (600 ohm) or the Senn HD650. But having a reasonably decent amp (like the Magni 2Uber) definitely helps. 

 

[drwlf]

  I've been switching back and forth between a THX00 Mahogany and the HE400i.  I really appreciate the HE400i, the sound might be "thin" at first, but I would give it some time and also turn up the volume (maybe turn on high gain?).  I've found the sound to simply be superb for any electronic music (which is what I mainly listen to while working), old Metallica albums I've been listening to again recently.  I primarily listen to them at my desk from a Modi Multibit into a Magni 2Uber.
 
The album that really opened my eyes to these cans was XXYYXX's self titled album, XXYYXX.
 
I've found them not great for gaming or movies, they're fine but the K7XX is vastly superior to me.  Speed and detail are where these cans shine, and I can't get enough of how I perceive the bass to be textured.  Even though they don't slam, damn they sound good and the bass is just so pleasant.

 
I think the 400i's performance is solid with lower volumes due to their exciting nature, but perhaps they are relatively thinner then, as you said it: you can add a tad of heft/tonal thickness via increasing the volume. Their nature does change a bit with adding the volume, which is kind of a flaw. I found myself ramping up the volume with 400i every now and then, which I don't need to seem to do as much with the LCD-X, as volume change is just a linear, effortless thing without losing/adding anything at all. And of course the LCD-X has some flaws as well.
 
And about that giving time thing: yeah, coming from dynamics to your first planar, it takes a while for your brain to understand what's going on. Coming from a thinner, and extremely bass rolled-off AKG Q701, I thought the 400i was bass-shyer for the first few weeks. Seriously.
 
And electronic music on the 400i, I agree.
The unnaturally quick transients, impulse response and the treble attack with well-produced electronic music can be a euphoric experience. Combine that with the artificial treble peaks, the 400i just forces you to listen, and focus. That comes with a price: badly produced stuff does sound awful.
I feel the 400i is quite genre-dependant (due to the unnaturally quick transients, harmonics, FR tuning etc.), and obviously production-dependant. Then again, I think the 400i is quite a good all-rounder nonetheless; but I'm annoyed by the fact that some genres cannot achieve those euphoric highs - some stuff actually sounds quite off. But then again, which can is very good with everything for your personal tastes.
And generally speaking, the detail in the bass is incredible. Way more than anything else in the price point. Perhaps it's just on the verge of what the driver can actually do, as boosting bass take some detail in the timbre away. And yeah, some electronic music could definitely use some tonal thickness. 400i cannot do that. It's not a slam monster by any means.
 
Regarding these observations vs. the LCD-X. The LCD-X isn't as exciting in the sense of forcing you to _listen_ all the time. Pointing out details all the time. The detail retrieval is undoubtedly superior to the 400i, and effortless - but you're in control yourself, if you want to focus on the details, they're there, and it's a joy to pick them out, but if you just want to get lost in the music, you can do that as well. And I'm talking about the least romantic, lush and musical of the Audeze line Still haven't got the amp sorted out for this at home. Work in progress!
And yeah, did I mention the face-melting slamming properties? It feels like two speakers wrapped around your head in plush lambskin leather. Weighing like the beforementioned speakers. These things even have some speaker-like forgivingness going on as well. I have yet to find any record to sound awful, it's often vice versa. Did some gaming to pass the time at some point, and I actually enjoyed some hideous music which was in turd-like quality. It was an odd experience.
 
 

   
I think the sound is not thin at all but it depends on what headphones you are used to, compared to the lower end Grado's I'd say they might be a little thin but not at all bad but if you are using HD650 or SRH-1840 then the HE400i will be thin sounding but if you were using Beyer DT-990 or T90 then the HE400i is not a thin sounding headphone, its all relative.
 
My SR225e (modded) is fuller sounding than the HE400i but even then I wouldn't consider either to be "full" sounding since my reference for full sounding is the HD650, EL8 or LCD-2.

 
And yeah, exactly what I was after by mentioning the reference point! Thinner than the HD650, but thicker than the general AKG/Beyerdynamic tuning.
 

I was expecting something like a budget LCD2 out of these. What I did learn is that my Angies are awesome.

 
I hope my rambling was helpful to you/others.
The 400i does make very good value for the money. It's good value against the LCD-2; but then it comes down to the personal preferences about tuning. It's just nothing like a budget LCD-2. (The very early impressions seem to point that the M1060 might be, though the thread seems to be flowing with bodily fluids due to the ongoing circlejerk, can't really decipher any proper information out of it!)

 

[Mani ATH 87]

I don't find the he400i to be thin at all. Obviously it has less warmth then the hd650, but it's a silly comparison. The 650's are known for being extremely warm and full bodied, to the point people see them as being veiled. Comparing most headphones to the presentation of the hd650 you are going to say, "they sound thin in comparison".
 
I actually like the low end on the he400i better then on the 650's, it also has a more detailed and clearer treble. The body and warmth of the midrange on the he650 is just untouchable, but I like the he400i in the other categories. 
 
I'm not sure why people feel the 400i lacks slam in the low end, a few others have mentioned here that people are just use to headphones with more of a mid bass hump. I personally find the 400i has great low end (sub bass) slam. The low end responds especially well to EQ as well, so if it isn't adequate for your EDM type stuff, give them a bit of a bump on the low end and I think they sound awesome. 

 

[Music freak]

   
I think the sound is not thin at all but it depends on what headphones you are used to, compared to the lower end Grado's I'd say they might be a little thin but not at all bad but if you are using HD650 or SRH-1840 then the HE400i will be thin sounding but if you were using Beyer DT-990 or T90 then the HE400i is not a thin sounding headphone, its all relative.
 
My SR225e (modded) is fuller sounding than the HE400i but even then I wouldn't consider either to be "full" sounding since my reference for full sounding is the HD650, EL8 or LCD-2.

I see. I am used to the HD 650's and the DT 150's rich sound. you know how much I love their sound. I am not expecting the HE 400is to sound as euphonic as the 650s. I don't mind less lushness as long as they don't sound dry and lifeless like some AKG cans I tried.
I am  a student who is addicted to this audiophile hobby. I am not rich, I save money for long to  buy these expensive headphones. So if I spent money on an expensive product that I dislike, I would be pretty disappointed. Also, In my country, I can't return the product once purchased. 
Now the reason I got interested in this headphone is that many people claim here that the planar bass is unique sounding and is vastly superior compared to dynamic headphones. I want to have that experience . I am buying them mainly for the bass. I hope that I am not just falling for some hype and later find out that it does not sound that unique compared to the dynamic headphones that I own.
 
Also, I see you being active a lot in the forums. I don't know if people tell you this , but I really appreciate your helpful nature. 

 

[Music freak]

   
I think the 400i's performance is solid with lower volumes due to their exciting nature, but perhaps they are relatively thinner then, as you said it: you can add a tad of heft/tonal thickness via increasing the volume. Their nature does change a bit with adding the volume, which is kind of a flaw. I found myself ramping up the volume with 400i every now and then, which I don't need to seem to do as much with the LCD-X, as volume change is just a linear, effortless thing without losing/adding anything at all. And of course the LCD-X has some flaws as well.
 
And about that giving time thing: yeah, coming from dynamics to your first planar, it takes a while for your brain to understand what's going on. Coming from a thinner, and extremely bass rolled-off AKG Q701, I thought the 400i was bass-shyer for the first few weeks. Seriously.
 
And electronic music on the 400i, I agree.
The unnaturally quick transients, impulse response and the treble attack with well-produced electronic music can be a euphoric experience. Combine that with the artificial treble peaks, the 400i just forces you to listen, and focus. That comes with a price: badly produced stuff does sound awful.
I feel the 400i is quite genre-dependant (due to the unnaturally quick transients, harmonics, FR tuning etc.), and obviously production-dependant. Then again, I think the 400i is quite a good all-rounder nonetheless; but I'm annoyed by the fact that some genres cannot achieve those euphoric highs - some stuff actually sounds quite off. But then again, which can is very good with everything for your personal tastes.
And generally speaking, the detail in the bass is incredible. Way more than anything else in the price point. Perhaps it's just on the verge of what the driver can actually do, as boosting bass take some detail in the timbre away. And yeah, some electronic music could definitely use some tonal thickness. 400i cannot do that. It's not a slam monster by any means.
 
Regarding these observations vs. the LCD-X. The LCD-X isn't as exciting in the sense of forcing you to _listen_ all the time. Pointing out details all the time. The detail retrieval is undoubtedly superior to the 400i, and effortless - but you're in control yourself, if you want to focus on the details, they're there, and it's a joy to pick them out, but if you just want to get lost in the music, you can do that as well. And I'm talking about the least romantic, lush and musical of the Audeze line Still haven't got the amp sorted out for this at home. Work in progress!
And yeah, did I mention the face-melting slamming properties? It feels like two speakers wrapped around your head in plush lambskin leather. Weighing like the beforementioned speakers. These things even have some speaker-like forgivingness going on as well. I have yet to find any record to sound awful, it's often vice versa. Did some gaming to pass the time at some point, and I actually enjoyed some hideous music which was in turd-like quality. It was an odd experience.
 
 
 
And yeah, exactly what I was after by mentioning the reference point! Thinner than the HD650, but thicker than the general AKG/Beyerdynamic tuning.
 
 
I hope my rambling was helpful to you/others.
The 400i does make very good value for the money. It's good value against the LCD-2; but then it comes down to the personal preferences about tuning. It's just nothing like a budget LCD-2. (The very early impressions seem to point that the M1060 might be, though the thread seems to be flowing with bodily fluids due to the ongoing circlejerk, can't really decipher any proper information out of it!)

That's good and useful information. what electronic music do you listen to? I mostly listen to uplifting house and trance. I love vocal trance as well. How do they perform with such music?

 

[DavidA]

  I see. I am used to the HD 650's and the DT 150's rich sound. you know how much I love their sound. I am not expecting the HE 400is to sound as euphonic as the 650s. I don't mind less lushness as long as they don't sound dry and lifeless like some AKG cans I tried.
I am  a student who is addicted to this audiophile hobby. I am not rich, I save money for long to  buy these expensive headphones. So if I spent money on an expensive product that I dislike, I would be pretty disappointed. Also, In my country, I can't return the product once purchased. 
Now the reason I got interested in this headphone is that many people claim here that the planar bass is unique sounding and is vastly superior compared to dynamic headphones. I want to have that experience . I am buying them mainly for the bass. I hope that I am not just falling for some hype and later find out that it does not sound that unique compared to the dynamic headphones that I own.
 
Also, I see you being active a lot in the forums. I don't know if people tell you this , but I really appreciate your helpful nature. 

The thing with the HE400i is it will sound thin compared to your HD650 and DT150 at first but if you give it a chance it just might be a great headphone to you.  You might want to be a little concerned with build quality of the HE400i, a few others have had some issues with them lately so make sure you can get a replacement if you get a defective one. 
 
If anything the HE400i will give you along with the HD650 two very common headphones that many compare other headphone to so over time it will help you understand impressions of others and help you to better understand what you like and dislike.  A few other things to consider, the genre of music and the volume that one listens at are important to note when reading some reviews because some headphones sound different depending on how loud a person listens at.  An example is a Grado headphone, most consider them bright but to some its really bad since they listen at very high volumes because they want more bass but the mids and highs are what seems to get louder faster than the bass so going louder only makes the brightness worse.
 
And thank you for saying I'm helpful at times, I've been retired for a few years (took an early retirement offer from Govt work, I used to be a designer/project engineer), along with my GF and friends we love getting together to listen to music, cook, and drink wine or other sprits.

 

[InsTwin]

  That's good and useful information. what electronic music do you listen to? I mostly listen to uplifting house and trance. I love vocal trance as well. How do they perform with such music?

I mostly listen to House music (not necessarily uplifting) with the 400i and it sounds quite excellent. You can hear very deep into the tracks, and everything is clean, clear, and the attack is superb.
 
Just give them proper brain-burn-in time. I was a bit disappointed out of the box with them, but now I think they are really quite superb.  They are my general go-to cans for when I want to do a long music listening session, as opposed to the THX00 which I've found myself reaching for more when I don't want to disturb anyone else, or the K7XX which I use to game or watch movies or the occasional listening session just to revisit them.
 
I swapped pads almost immediately to the HM5 Flat Hybrid pads which did little to the sound signature but made them a lot more comfortable to me.  I generally like the HM5 pads as a good value, though.  I did not like the pads they came with at all.
 
Edit: One other thing, the HE400i will not make a poorly produced track sound better, good production is remarkably evident.

 

[drwlf]

  I don't find the he400i to be thin at all. Obviously it has less warmth then the hd650, but it's a silly comparison. The 650's are known for being extremely warm and full bodied, to the point people see them as being veiled. Comparing most headphones to the presentation of the hd650 you are going to say, "they sound thin in comparison".
 
I actually like the low end on the he400i better then on the 650's, it also has a more detailed and clearer treble. The body and warmth of the midrange on the he650 is just untouchable, but I like the he400i in the other categories. 
 
I'm not sure why people feel the 400i lacks slam in the low end, a few others have mentioned here that people are just use to headphones with more of a mid bass hump. I personally find the 400i has great low end (sub bass) slam. The low end responds especially well to EQ as well, so if it isn't adequate for your EDM type stuff, give them a bit of a bump on the low end and I think they sound awesome. 

 
We can agree to disagree! We're not comparing the HD650 to most other cans here - there's also cans which are tonally thicker than the 650. Where does the 400i sit then? I think it simply sits a bit on the thinner side. IMO both the 400i and HD650 do the lower frequencies well for their intended purpose; they're just different.
Somebody mentioned the 400i being neutral, but I don't think that's reasonable, as striving for true neutrality, especially if you're coming from speakers, the general tonality shouldn't be as thin, however, there's quite a lot of truth in this statement. (I just rather recently got into headphones, although I knew the basics of headphones. That being said, the 650 is quite speaker-like, and it's strong points do trump lower end speaker setups easily.)
What I mean by this, the general tuning of 400i is reminiscent of what "master reference" was years prior in headphones for ages - weird peaky treble, enhancing the detail artificially. Often quite thin. That simply shouldn't be required. The 400i is quite similar in that aspect, although one major trait is fundamentally different - the bass is actually neutral, and not rolled off!
It seemed to be a technical impossibility for dynamic drivers to achieve a neutral bass without roll-off, and most importantly, which was distortion free. (The latest dynamic drivers seem to have bridged these gaps quite a bit.)
The 650s bass has the roll-off, and the distortion has been carefully tuned to emulate a speaker-like feeling, along with resonances and harmonics.
Let me give you an example to illustrate my points, and a brief cross-examination with the 400i regarding the bass aspect: David Maxim Micic, two tracks from the album "Bilo 3.0" which highlight the differences and strengths in both of these cans. (on Spotify Premium, not Tidal, got the FLAC, and it's reasonable quality on the Spotifys version to actually understand what I'm talking about).
It's a djent album, but the track "Nostalgia", a proggy-vibed jazz fusion piece. The bass guitar is tuned exceptionally low, and the harmonics along with the distortion - with the HD650, you get a forgiving, warm sound, which is quite speaker-like, smooth and most importantly: natural sounding. Try the same track with 400i. No distortion here, it re-produces it well technically, but it truly sounds off, unnatural and electronic. It sounds like ass. Tonal thickness would help here, but there's other issues at play here, the impulse response and harmonics are off to call it natural. We could debate how, and why this is produced like this - but the fact is, often production doesn't address issues in these frequencies to favor the 400i, it's usually vice versa. Not to mention my problems with the beforementioned, in other frequencies, in most guitar music. And then again - well produced electronic music favors the 400i, there's no doubt about that.
Then the next track, from the same album, "Wrinkle Maze", an ambient orchestral piece, which surprises you with an electronic sub-bass, (and later transforms into a heavier choral epic with the guitar solo along with the DTP-esque intended distortion blast at the start of the second part.) Well, it doesn't sound like ass on the 650, albeit not great - but my god at the electronic sub-bass reproduction, and the general sound with the 400i. It's quite wonderful. See what I'm after?
And no, I won't even engage in discussion about the mid-bass hump/dynamic driver bass-head cans. Slam and/or to a degree impact can be found from planars as well. The 400i does lack slam, not to mention impact, unless you're talking about the treble attack.
 
 

  I see. I am used to the HD 650's and the DT 150's rich sound. you know how much I love their sound. I am not expecting the HE 400is to sound as euphonic as the 650s. I don't mind less lushness as long as they don't sound dry and lifeless like some AKG cans I tried.
I am  a student who is addicted to this audiophile hobby. I am not rich, I save money for long to  buy these expensive headphones. So if I spent money on an expensive product that I dislike, I would be pretty disappointed. Also, In my country, I can't return the product once purchased. 
Now the reason I got interested in this headphone is that many people claim here that the planar bass is unique sounding and is vastly superior compared to dynamic headphones. I want to have that experience . I am buying them mainly for the bass. I hope that I am not just falling for some hype and later find out that it does not sound that unique compared to the dynamic headphones that I own.
 
Also, I see you being active a lot in the forums. I don't know if people tell you this , but I really appreciate your helpful nature. 

 
The 400i is just as euphoric as the HD650, it's just a bit more genre-dependant! There's no correlation with the AKG/Beyerdynamic sound, lifeless wouldn't be a word to describe the 400i, it's not sterile.
 

  That's good and useful information. what electronic music do you listen to? I mostly listen to uplifting house and trance. I love vocal trance as well. How do they perform with such music?

 
Sadly, no vocal electronic for me. I'm quite into IDM/glitch/downtempo recently, due to the 400i! Basically I haven't been listening to a lot of electronic music before the 400i, excluding the really experimental stuff, along the lines of electronic jazz/demo scene/psytrance, which I got into in the late 90s.
 

  The thing with the HE400i is it will sound thin compared to your HD650 and DT150 at first but if you give it a chance it just might be a great headphone to you.  You might want to be a little concerned with build quality of the HE400i, a few others have had some issues with them lately so make sure you can get a replacement if you get a defective one. 
 
If anything the HE400i will give you along with the HD650 two very common headphones that many compare other headphone to so over time it will help you understand impressions of others and help you to better understand what you like and dislike.  A few other things to consider, the genre of music and the volume that one listens at are important to note when reading some reviews because some headphones sound different depending on how loud a person listens at.  An example is a Grado headphone, most consider them bright but to some its really bad since they listen at very high volumes because they want more bass but the mids and highs are what seems to get louder faster than the bass so going louder only makes the brightness worse.
 

 
Couldn't have expressed this better!

 

[peter123]

Interesting discussion. To me the HD650 is more genre dependant and the HE400i the better all-round headphone. I also fail to hear that the HD650 has more slam than the HE400i. To my ears the HD650 is thick and soft but doesn't offer much slam, the HE400i has more and better subbass bass slam the way I hear things.

As always (and obviously) YMMV.

 

[drwlf]

Interesting discussion. To me the HD650 is more genre dependant and the HE400i the better all-round headphone. I also fail to hear that the HD650 has more slam than the HE400i. To my ears the HD650 is thick and soft but doesn't offer much slam, the HE400i has more and better subbass bass slam the way I hear things.

As always (and obviously) YMMV.

Yeah, these slam/impact things are quite YMMV, and no, I wasn't saying that about the 650! Might have had a few vodkas!
The genres you listen to have a tremendous impact, along with my personal annoyances about some genres, which bring the 400i down more. The 650 is more forgiving in a broader sense.