While I was researching which headphones to purchase I felt that there wasn't as many reviews of the HE-400 as I would like, and now that I have them I thought I'd add my thoughts. First off I'm new to the world of audiophile; I've been interested for quite some time but I never had any really good equipment. Before these cans I had the Sennheiser HD 280 which would be a pointless comparison. So instead I will do my best to describe the sound without comparisons to any other cans. Perhaps this review will be of more use to other newbies like me who gain little or no info from comparisons.
This is my first in depth review...
All listening was done using the ASUS Xonar Essence STX sound card and foobar2000 with ASIO output.
Build quality/comfort and packaging
The packaging is simple, no extras or fancy cases, only a small carrying pouch, no extra earpads, just the headphones and the cable. Makes sense seeing as this is HiFiMAN's budget model. I have no need for a carrying case anyway so I'm glad I'm not forced to pay for one... First thing I notice upon taking them out of the box is the weight and feel. Heavy, mostly metal, built like a tank. These are very unlikely to break no matter how rough you treat them (although mine are going to be cared for like a small child). The cable is nothing special, I have no complaints; it is a little stiff, but I appreciate that it does not try to retain the shape it was in within the box. The screw-type connectors feel very sturdy once you get them on, but it is a little difficult to screw the cable on. I have some of the skinniest fingers you'll ever see and it still took me a few minutes to get it right. The earpads are simple enough to replace, but I'm not sure how easily the tabs would break if removed repeatedly, they do seem a little fragile. There is up/down, pivot, swivel adjustments for the headphones, and once you have them properly adjusted I am confident they will stay that way (for those like me who are annoyed by constantly re-adjusting). Overall these cans are fairly comfortable, although a bit heavy (they are significantly heavier than most dynamic 'phones) which could be a problem for some. They have a comfortable amount of clamping force IMO (but then again I feel that the clamp force of the HD 280 is perfectly fine, so I'm not sure my opinion here means much).
Now on to what really matters... I should note that these are the rev. 2 drivers; also I am reviewing these using the velour earpads, many reviews said they sound better and they're only $10 so I figured its worth the upgrade (more on the sound differences later). I have only been listening for a few hours, so they are not yet burned in much, I will update if there are any major changes.
When people say planar-magnetic have a sound like no other, I now know what they mean. Its difficult to put into words, its just better in every way. Highly linear with no peaks, the bass midrange and treble just blend together seamlessly. There is a fluid-like smoothness that is just on a whole different level compared to dynamic drivers.
The bass response on these cans is all I had hoped for and more. The bass is plentiful without being overpowering. I am a bit of a self-proclaimed basshead, and these completely satisfy that craving. They should have enough bass for most people, except maybe the ones who want pulse-pounding skull-shaking quantities of low end. The bass is also of amazing quality. It extends lower than I can hear (maybe <15 Hz) and has zero muddiness or distortion, amazing clarity. I can hear every finger pluck of the strings on a bass guitar. The impact of drums or the punch in the chest bass of dubstep is just awesome. **Note: it takes at least an hour of burn in for the impact to be apparent, I was a little disappointed at first but now its great**
I used to be a fan of the v-shaped response curve, but these cans may have just converted me... The mids are by far the clearest I have heard and incredibly linear. Vocals sound as though I am on stage or in the recording studio next to the singer. Acoustic guitar is absolutely jaw-dropping. I simply cannot find the proper words to describe the clarity and detail of the midrange.
The highs are again super detailed, with zero fatigue or harshness even at loud volumes. There is no silibance unless the recording is of low quality, and even then only slight. Extends higher than I can hear with no major peaks, very linear. I can hear the pick hitting against every string in a guitar solo. High female vocals are just awe-inspiring.
Incredibly wide, the music is all around me. Its as if I am in the studio while they are recording. Live recordings sound as if I am up on stage overlooking the crowd right next to the lead vocals.
These cans are great for any genre I can imagine. I would recommend them to anyone who has the money. The only con I can think of is that they are so detailed that low quality recordings will be just that: low quality. Every error will become apparent. *More on the earpads: I tried the leather to see the difference for myself. The treble is just not as present or detailed, definitely get the velours, for only $10 its a great improvement.