Subjective Performance and Conclusion
I did not use any dedicated headphone amplifier with the H840, relying exclusively on the built-in output from the various devices I connected them to. (I imagine that most people looking into monitor headphones in this price range wouldn't be using a dedicated headphone amp.) I found that a smartphone's headphone jack (I used both a Nexus 6 and an iPhone 6s Plus) was more than sufficient to provide loud, clear music from these headphones. I needed to turn the volume up a little higher than my usual headphones, but at 90 dB sensitivity these were plenty loud. So how did they sound?
In the interest of brevity, I'll describe one of the many tracks I listened to. It's been my favorite demo track for the past year or so; the title track on Shelby Lynn’s Just a Little Lovin’ (Analogue Productions, DSD). This album has a clean, rich sound with plenty of space around the instruments; it combines firm bass, crisp treble from the cymbal work, and the rich midrange of Lynn’s voice. Besides being a great listen in general, this track allows me to focus on different aspects of headphone performance, especially considering (in most cases) there is a single driver coping with this very wide range of sound.
The Edifier H840 handled this track as well as anything else I tried. Using my Calyx M DAP, I played back the native DSD file and was immediately treated to clear, powerful sound. The bass line that opens the song is a great test, and while it sounded just a bit smooth (not quite as much bite as I’ve heard) it was weighty and satisfying. Even better, there was no tradeoff whatsoever with treble performance, which amazed me throughout my listening sessions. Midrange was a bit recessed, but this could be as much my familiarity with the Grado sound (slightly forward midrange) as anything. Even comparing these to my Audio Technica AD700X (open-back) headphones, which have a more neutral sound than anything else I’ve owned, I felt like the H840 had a more dynamic sound (if less neutral overall).
In the end, and after listening to music spanning my entire collection, I was highly impressed with the sound from these headphones. I mentioned the word "dynamic", and I think that's my biggest takaway from these. They handled sudden shifts in volume extremely well, lending themselves perfectly to movies and game audio. There's virtually no emotional impact from cheap earbuds, and even some pricier headphones I've heard didn't do as well at producing the dynamics the H840's were capable of. Loud explosions had real impact, and bass was quite impressive. They definately worked well as gaming headphones, not only for the quality sound but also because they do a pretty good job with noise isolation (who wants to hear a screaming GPU fan after gaming for a few hours?).
The H840 can deliver powerful bass, but they don’t have a one-note design. There is a wonderful balance between the upper bass and the highest treble – about as good with these any any headphone I’ve heard. The articulation and space from high frequencies are outstanding. Crisp, yet silky. Midrange is just a bit soft, reminding me of that well-known “smile” EQ pattern; but it’s subtle. The only thing that seems boosted is the bass, though this isn’t overpowering. The low-end response was enough to create a bit of boom on some bass-heavy tracks (a slight EQ adjustment is all you’d need to correct this), but lighter mixes received a nice weight from the H840.
My previous recommendation for a good headphone in the $50 range has been the Grado iGrado, but compared to the Edifier H840 the entry-level Grado isn't close. I love Grado’s sound from the higher end Prestige line, with the SR325 one of my all-time favorite headphones, but reaching that level of refinement costs $295. Sure, these could have had a slightly more balanced bass response, and the build quality is nothing special. But for the price, they're fantastic.
The Edifier H840 was so good at presenting a refined, articulate, and above all engaging sound, that I would have to recommend it over anything else at this price. I have yet to hear anything that could match it for less than $100. It really makes me want to hear the larger H850, (which is still only $59 on Amazon). Well done!