[obsidyen]

...

 

[SodaBoy]

The HE400S is $299 USD on Amazon, and the HD 650 is at $467.9, the Amazon prices will fluctuate due to dynamic pricing, but this is the ball-park price.
 
In measurements (which I believe correlate very well to the listening experience), the two headphones have a very similar FR and both do very well in this area.
 
When we get down to the distortion measurements, I am primarily looking at the 90dB THD+N, as I do not listen anywhere close to 100dB beyond short transients. The HE400S matches the HD 650 in distortion throughout the midrange and treble, but distorts significantly less in the lower octaves which is what I would expect from a planar.
 
I won't comment on the impulse response even though the HE400S excels in this area, since I don't understand why the HD 650 impulse response looks so off, given its frequency response. I have looked at the HD 650 CSD, and it looked very clean, so I feel there something very odd about its impulse response measurement.
 
On durability, I don't know the durability of the HE400S, but given the track record of Hifiman I don't expect it to be below par. On the other hand, the HD 650 is as functionally durable as I expect all headphones to be, but its headband paint flakes easily due to a design flaw which leaves it looking pretty worn not long after purchase. Not good.
 
The HE400S is a $299 headphone that either matches or exceeds all headphones to my knowledge in the under $500 bracket. Since it is cheaper than the competition, that makes it the winner in my book.

 

[conquerator2]

Impressions vary through the roof

 

[bracko]

Impressions vary through the roof

 
As usual 

 

[conquerator2]

With this headphone, I feel it's quite a lot

 

[bracko]

With this headphone, I feel it's quite a lot

And some people don't even need to hear the gear. They have an opinion nevertheless. I wonder how we can put some music into those measurement graphs 

 

[Pianist]

  For me comparing the X2 with the 400S using InnerFidelity graphs the midrange looks smoother on the 400S not the X2.

 
Actually, my bad. I think they are both quite linear in the mids. X2 drivers are better matched, but it has a slight, but odd dip at 2 kHz, which is likely not even audible at all. HE-400S has some irregularities in the right channel (red) between 200Hz and 1 kHz, but that's also likely inaudible. Distortion levels are similar. Square waves are a bit better looking on HE-400S. Impulse response is cleaner on the HE-400S, but then HE-500 had terrible impluse response on Innerfidelity measurements, but sounded great... Measurements certainly don't tell the whole story.
 
Also, remember the law of diminshing returns. The best, most effective upgrades in sound quality you can get from most of the cheapo stock earbuds that come with portable players/smartphones or those poorly designed and grossly overpriced "celebrity" headphones are sub $100 and even sub-$50 headphones, such as KCS75, PortaPro, PX100 or SR60. Dimnishinbg returns hit hard beyond those. Then, there's a more significant reduction in price/performance beyond mid level headphones, such as HD558/598, DT660/860 and K550. The differences between mid/hi-fi level headphones of HP50/MSR7/HD600/X2/HE-400S/i/HE-500 are not very large at all. I would even say minimal. Yes, there can be big differences in tuning/frequency response, but not in absolute sound quality. Some of them really stand out in some aspects - MSR7 has transients about on par with high-end cans like HD800 and stats for example, but loses out significantly to HD600, X2 or the Hifiman planars in dynamics and soundstage, so overall it's actually not really better than than an HD600 or X2 or HE-400. or HE-400S can beat most dynamics in bass texture and perhaps clarity in the high end, but ultimately it will surely fall short elsewhere. With planars, I find that texture/micro detail and soundstage, specifically imaging specificity/sharpness is usually lacking compared to high quality dynamic headphones.

 

[Pianist]

  The HE400S is $299 USD on Amazon, and the HD 650 is at $467.9, the Amazon prices will fluctuate due to dynamic pricing, but this is the ball-park price.
 
In measurements (which I believe correlate very well to the listening experience), the two headphones have a very similar FR and both do very well in this area.
 
When we get down to the distortion measurements, I am primarily looking at the 90dB THD+N, as I do not listen anywhere close to 100dB beyond short transients. The HE400S matches the HD 650 in distortion throughout the midrange and treble, but distorts significantly less in the lower octaves which is what I would expect from a planar.
 
I won't comment on the impulse response even though the HE400S excels in this area, since I don't understand why the HD 650 impulse response looks so off, given its frequency response. I have looked at the HD 650 CSD, and it looked very clean, so I feel there something very odd about its impulse response measurement.
 
On durability, I don't know the durability of the HE400S, but given the track record of Hifiman I don't expect it to be below par. On the other hand, the HD 650 is as functionally durable as I expect all headphones to be, but its headband paint flakes easily due to a design flaw which leaves it looking pretty worn not long after purchase. Not good.
 
The HE400S is a $299 headphone that either matches or exceeds all headphones to my knowledge in the under $500 bracket. Since it is cheaper than the competition, that makes it the winner in my book.

 
I have no doubt that HD650 at $400+ is overpriced compared to HE-400S at $299, although if HD650 was, say, around $350 or so, then it may be worth it to many due to its time-tested durability great design where all parts are replaceable, right down to the drivers. In terms of sound quality, I am sure that they are on about the same level overall and it will come down to personal tastes which one sounds better.
 
HD600 at $336 and Fidelio X2 at $299 are real competitors to the HE-400S. I also really like the AKG K612 Pro, which I believe is almost as good as X2 and HD600 overall and better in some aspects of sound quality, but can be had for dirt cheap compared to the other two. If I was on a tight budget, I would go for the K612 Pro as it's <50% the price of X2, HD600 and HE-400S, while offering maybe 85 to 110% the performance depending on taste and what music you listen to.
 
EDIT: I apologize for the two posts in a row... Sorry mods, I am not trying to increase my post count, I swear! lol

 

[bracko]

I have no doubt that HD650 at $400+ is overpriced compared to HE-400S at $299, although if HD650 was, say, around $350 or so, then it may be worth it to many due to its time-tested durability great design where all parts are replaceable, right down to the drivers. In terms of sound quality, I am sure that they are on about the same level overall and it will come down to personal tastes which one sounds better.

HD600 at $336 and Fidelio X2 at $299 are real competitors to the HE-400S. I also really like the AKG K612 Pro, which I believe is almost as good as X2 and HD600 overall and better in some aspects of sound quality, but can be had for dirt cheap compared to the other two. If I was on a tight budget, I would go for the K612 Pro as it's <50% the price of X2, HD600 and HE-400S, while offering maybe 85 to 110% the performance depending on taste and what music you listen to.

What you say here is applicable to any headphone or relation between any two given headphones. At the end of the road it is our preferences that matter the most.

 

[Pianist]

What you say here is applicable to any headphone or relation between any two given headphones.

 
What do you mean? A relation between Beats Pro and HE-400S is surely very different than relation between HD600 and HE-400S, although they are all roughly in the same price range. HD600 and HE-400S are worth their price compared to most lower price headphones, while Beats Pro isn't...

 

[bracko]

What do you mean? A relation between Beats Pro and HE-400S is surely very different than relation between HD600 and HE-400S...

Is it? Even for people who buy Beats?

 

[Pianist]

Is it? Even for people who buy Beats?

 
In that post I was talking in terms sound quality, build and design quality, not styling or tuning. Built quality on the Beats is solid, but the design is not that great, because the end up being too heavy due to too much metal used in the design (they weigh over 400 grams). They are also awkwardly large and bulky. In terms of sound quality, as we all know, Beats are lacking for the price. They perform on the level of a decent $200 closed can at best and can't match the performance of the best $200-300 closed back headphones such as HP50 or MSR7.

 

[mysticstryk]

How would the 400s perform with genres like symphonic metal, orchestra, ambient electronic, synth wave...with vocals in my music encompassing both male and female artists?

I have the X2 but feel they lag somewhat in the mids and treble isn't as smooth as I like and can be a bit grainy.

My other option is the hd650. Such a hard decision that I've been mulling for weeks over! Haha

 

[Gino]

I am not sure how the HD-600/650 do connected to a phone but this HE-400S does a pretty good job. This informal way to listen with services like Spotify puts the the HE-400S in quite a unique position. I listen this way most of the time for the large selection of material. 

 

[sheldaze]

  I am not sure how the HD-600/650 do connected to a phone but this HE-400S does a pretty good job. This informal way to listen with services like Spotify puts the the HE-400S in quite a unique position. I listen this way most of the time for the large selection of material. 

I'm staring to think I have a very different opinion regarding these headphones than everyone here 

 
Per your suggestion, I plugged these into my iPhone 6+. But I think I'll keep my opinion to myself this time. I love these headphones, just not in any of the ways people here do