[Poetic]

Can someone do a comparison between the two and how they complement each other. Thankyou

 

[kstuart]

I have had the SRH-1840 for awhile, and just received the HE-400.
 
Short Summary:
 
SRH-1840 is very detailed, with excellent instrument positioning, flat frequency response (outside perhaps of a bump or two on the high end, but there doesn't seem to be any headphones yet that don't have some - perhaps the $1,000+ ones ?). Their flat frequency response means that the bass - even though it is there, and sounds good - seems low, because - unlike speakers - you can't feel the bass in your body.  Adding more bass, so that it is like listening to big speakers, would obscure some of the detail, and lose some of the "air" that is responsible for the great instrument definition. They would be very good for studio monitoring (although they are open back), which is no surprise, since they are made by Shure.
 
HE-400 has really excellent bass - both in quantity and quality.  I think that any more bass would not be very listenable.  This makes the headphones not flat.  But since there is no "felt" bass in your body, it makes the headphones seem to have a more real life bass response.  So, if you are listening to something where the bass is very important to the overall sound quality, then the HE-400 is top notch, since - from my reading of reviews - any headphones with similar bass are either a) a lot more money, or b) have poor quality mids or highs.
 
Examples:
 
Miles Davis - Kind of Blue - "So What" :  Shure beautifully presents every detail of the instruments - piano timbre, tongue attack on the trumpet, finger on the bass strings, shimmer of the cymbals.   HiFiMan makes the upright bass sound very real, you feel the resonance of the bass body when he plucks the strings.  Cymbals are also very detailed and close to the quality of the Shure treble.  But the piano on the HiFiMan is more muted and a little dull.   Both give a very good experience of the classic piece, the Shure giving you a clearer view of all instruments.
 
Pink Floyd - Dark Side of the Moon - "Time" :  Shure reproduces all the nuances of the guitar sound, and the vocals are excellent, and all the instruments and effects are clearly reproduced.  HiFiMan reproduces the impact of the bass guitar and bass drum better, and in this sort of music, gives it more rhythmic drive that is an important part of "beat" music   So, while the Shure has a little more detail, the HiFiMan is truer to the music and how it is supposed to sound.
 
So, for very rhythm oriented music (like rock), the HE-400 is top notch.  For music with natural acoustic instruments, like classical, folk, and acoustic jazz, the SRH-1840 is excellent.    Both are enjoyable in all genres of music, since they are relatively expensive, high-end headphones released in the last year.
 
By the way, the SRH-1840 are lighter in weight than the HE-400 and so more comfortable.  The weight of the HE-400 is acceptable or not depending on your personal experience, although I would think that if one really likes them, then you notice it less.    (Since the HE-500 supposedly weighs even more, then that sounds to me to be over the line into possible problem area.)
 
( I have not heard the HE-500, but what I have read about them seems to indicate that their frequency response is more like the SRH-1840, i.e. flat, without the bass emphasis of the HE-400.)