Superlux HD-681 EVO Black Professional Monitor Headphones

Build Quality: Quite bad, everything you'd expect at this price or worse.
The plastic literally squeaks, the headband is held by a rubber band on the inside, which breaks for a lot of people. The 3.5mm connector on the headphones will break after a couple months if you lay them flat on the table as you normally would, unless you have a stand it will happen so soldering a new connector is necessary.
Sound: Not an expert but these sound phenomenal with some EQ-ing (this makes everything better in my opinion but the bass is much more noticeable).
I love them the most with their pleather pads but many recommend getting velour pads.


4 stars because of the sound.

I just got these yesterday and am impressed enough to write this while drinking my morning coffee, which is quite a compliment. One key point I would make is that while several reviews mention a V-shaped sound signature and strong bass, how noticeable that is will depend on what your previous headphones were. To me, the bass in the JVC S500 I was using felt excessive at times and I was nervous that these would be the same. In reality, the bass in the 681EVO feels perhaps a tiny bit less pronounced and I like it. Overall, I'm impressed with the sound. Vocals sound alive, guitars sound great, drums are okay, and the soundstage feels spacious.
Other bullet points: The accessories are welcome. I switched to the velour pads immediately and prefer them. The 1m cable is great for my mp3 and being able to switch it is welcome. Isolation is noticeably worse than the S500, but that's not a surprise. To my ears, these sound better than my xiaomi piston 3.0.

Worth the money for anyone wanting a cheap pair of headphones. Won't blow anyone away but for $40 you can't do much better.
 
Build quality is lacking and the cables really suck, so these do have a definitive lifespan on them. Mine lasted me about 4 years.

I bought my headphones after thorough information on this site. That's why I thank to all who wrote a review, giving information to others. It helped me a lot! I'm very pleased to have a copy of those astonishing headphones. They have a stunning sound quality for the price. Having this in mind, I can overlook other characteristics such as build quality, materials etc.
My conclusion: Highly recommended for those who look for sound quality but still don't have a little fortune to spend.

I can't get over how much I love these cans. Except for the slightly bloated bottom, which doesn't reveal itself on most cuts, these sound as good as anything I've heard except crazy expensive stuff like HD800s and the original Orpheus. I like them better than the HD 580/600/650, K/Q701, and Beyer DT-880's, all of which I own now (not for long) or have owned for years. I absolutely love the big, easy spacious sound and the fact that they don't need an amp, which I consider a huge PItA. The proof of how good these are is, I can't take the damn things off! Un-modded they have some serious problems, but switching to the velour pads (included) and removing the foam discs reduces the problems to entirely acceptable levels.  

Well, I've been using these for 10 months, and I realized that I havent done a review for them, so here we go. This is also going to be a comparision againts the Superlux 668B.
 
First, I have to say that these headphones are somewhat underrated, they're way less popular than their brother (668B), and these deserve as much attention as the 668s or even more!
 
So lets start, Evos and 668s have two things in common, their soundstage and their V-shaped sound, the rest is diferent. Although both have a V-shape sound, Evos are also warm, with a great sub-bass thats really present and shines with Classical music and Jazz. (While 668s are really poor in that aspec howeer 668s have a faster mid-bass that I really enjoy). To resume it, Evos are Warm V shaped and 668s agressive V shaped. So If you're doubting about picking one of them you should really consider what headphone you want, because they are almost completely different.
 
Now lets go with the mids, they still have recess mids, they're present enough, even a little bit more than 668s and thanks to its timbre that we gonna talk on a moment, they are better.
 
Highs: Very detailed, not as much as 668s, both show recording mistakes easily, on the 668s you will heard any clipping/distortion right over the rest of instrument, on the Evos you will hear it too, but in this case they sound behind the rest of instrument, I would even consider this a good point, since some games soundtracks really have a poor quality and on the 668s is really hard to enjoy them (I'm looking at you Ace Combat X -.-)
 
Their highs are surely softer and with their amazing timbre that omg, really this aspect is something that surprises me a lot on the Evos, that Timbre makes everything sound better, more natural, 668s are well know for their "dry" timbre. thanks Superlux to for fixed it!
 
Now lets talk about gaming, and with that I mean soundstage and positioning, both headphones have a similar soundstage (Its really hard to tell to be honest) but I would say Evos extend a little bit more horizontally and less vertically.
 
However, Evos do depth and audio positioning amazingly better, I mean, I no longer game on my 668s, they could have as much detail as you want, but Evos positioning is brilliant, Now playing CS:GO it is super easy to tell when someone is coming from your 8 to 4 O'Clock (668s really struggle there) If you have both headphones, please tell me how do you find their positing on CS:GO, because maybe I'm crazy. xD I wasnt expecting that at all.
 
But they have a fatal flaw that really bugs me, and it is their build quality. Why???
 
I've been using these for 10 month, I've already recable them (the little cable that goes out of them broke off), the two metal beams that goes over your head have one tear each on the middle (although there's metal inside them, so this is not fatal) their headband have like 10 tears, all of them fixed with superglue that really prevents them from getting bigger.

I really dont know why this has happened to me, My 668s are one year older than my evos and they are still fine.

So, I do recommend this headphone to everyone, but you have to be aware of its building issues, if that really does not matter for you, go for them!
 
 
UPDATE: These were my impressions of the Evos plug on my Xonar DG. Recently, I performed a test between my Xonar DG and a ELE EL D02 and I realized that they sound better on the ELE DAC, basically that "slow bass" is gone (It is still slower than 668s bass though).
 
http://www.head-fi.org/t/677895/ele-dac-support-and-appreciation-thread/105#post_12043224

Superlux HD-681 EVO Review 
The Superlux HD-681 EVO is a pioneer in the world of audio quality. As this is a budget headphone, I will be critiquing, and comparing it to other headphones similar to it in price to sound correlation. This headphones had a distinct V shaped sound signature, and is intended mainly for listeners of modern genres, such as hip-hop, rock and pop. Older genres such as classical and jazz will not sound near their full quality with these headphones. The Superlux HD-681 EVOs are a worthy replacement to its predecessor, the Superlux 681 (older version) in both sound quality and aesthetics. The improvement in sound quality is mainly present in the treble, where the long hated sibilance has subsided. In addition, the improved aesthetics only make the headphone a more valuable asset. The overall sound is darker and v shaped, comparative to my sennheiser momentums and TDK 700s. These headphones have received universal acclaim across multiple forums and sites, for it sound quality, and cheap price.
 
 
This review consists of: Specifications, Highs, Mids, Lows, Build/Comfort, and a Conclusion 
 
Specifications 
Weight                          276 g
Driver Size                    50 mm
Frequency Response     10 - 30000 Hz
Magnet                         ferrite
Sensitivity                     98 dB
Impedance                    32 Ohms
Connectivity type           wired
Type                             Semi-Open, Over ear
 
Highs
The highs on the the HD-681 EVOs are vastly improved from the older superlux models of the 681. The old sibilance that caused ear fatigue are now gone. I found the highs to be very decent for the price. It is drastically better than other 40 sony or phillip models. Against the TDK 700, the EVO's highs wins by just a slim margin. It even manages to hold its own against other higher priced headphones, including the Audio Technica ATH - m50s and Sennheiser Momentums. Recommended and acclaimed for its price, but nothing special.
 
Mids
The mids on these headphones is its main weakness. The mids are lacking, even for a v shaped headphone. In transparency, they were among the lowest in my budget headphone collection. They simply lack the texture and quality of sound that any experienced audiophile will detect. Compared to the TDK 700, sennheiser momentums and even my apple earbuds, the mids loose out. For the price range of this headphone, I would say that the mids are lacking.
 
Lows
One of the best aspects of these headphones are its lows. The lows make up indefinitely for the mids of the headphones. I found the lows to be very smooth, with deep extension. While they do not muddle the mids like the ATH m50s do, they are reasonably well balanced with decent slam. Songs like Animals by Maroon 5, Centuries by Fall out boy and electronic mixes such as 
Back on Track sound stunning. While it lacks the speed of the ATH m50s, and the detail of my sennheiser 598s, it truly is a steal for 40 bucks. Highly recommended for its price. 
 
Build/Comfort
Inside the box, the Superlux HD 681 EVOs comes with two cables, a 1/4 inch audio jack adapter, and two sets of earpads, one of which is constructed of synthetic pleather. the other is fabricated of velour. I used the velour earpads on the headphones, as it proved to be more comfortable. The headphones are constructed of a durable plastic, and do not feel as if they would damage easily. The cable however, is abysmal in quality, and I would recommend replacing it with any other female to male adapter on Amazon. Luckily, the design of the headphone allows you to plug in a Bluetooth adapter for wireless listening. Because there is a 2 inch male cable that connects to the other two cables, any sort of lightweight Bluetooth adapter (OST Bluetooth adapt) will be able to plug in, and give you wireless audio. A very handy trick. 
 
As for comfort, the headphones were decently comfort. The earpads pressed on the top and bottom of my ears, and I could wear it an hour at most. However, compared to other budget headphones of the same price, it is one of the more comfortable headphones i could wear. 
 
Conclusion
The Superlux HD 681 EVOs is a dramatic improvement to its predecessor, the Superlux 681s. I regard it as one of the best headphone in sound quality and build that one can find for its price range, and would recommend it to others. The Highs and Bass make up for its lacking mids, and its wide range of accessories only make it more desirable. 
 
Overall rating 4.6 stars
Thanks! ☺

Introduction
 
This is a review of the Superlux hd 681 Evo, Version II. It is my first review on Head-Fi, so bear with me. The particular Evo under review here has roughly 40 hrs of burn-in time on it and you should be aware that many knowledgeable Evo users feel the proper burn-in time for these cans is more in the 150-220 hrs range, so keep that in mind when reading this review. The Version II is the newer of the Evo's and comes with an extra set of velour pads and two lengths of cable--one about right for portable players and the other, much longer one, for home use. There is a bag for the cans that seems rather smallish for the very ample HP of their intended joinder. Mine came from amazon and were well packed in a nice box with proper packing materials. I have no complaints with any of the packaging or shipping--they came in three days.
 
Design
 
The Evo are a semi-open headphone. This means you can hear the outside world, and the outside world can hear your music--when loud enough. The Evo's bear a striking resemblance to the AKG k240 cosmetically, if not from a listening point of view. The cable plugs into a short length thereof on the right (or left, depending on how you wear them) cup (male). The band is easily adjustable. Construction seems adequate for a can in this price range. They are neither tanks nor pieces of garbage. Somewhere in between the two, I would say. The primary material used seems to be some sort of plastic. The short cable is very nice for those of us who use portable players a lot or primarily. That said, having both lengths is also very nice.
 
Comfort
 
In some thirty-plus hours of listening, I have found the Evo to be plenty comfortable--more so now than when I first got them. Clamp pressure is fairly high on my smallish head and will be more on a larger one. There are several ways to deal with this, including using a box or pillows to reduce the tension (and opening the HP around this).. There are several other ways to reduce clamp pressure also in the forum on the Evo. I won't belabor them here. I would say that some people have found the velour pads more comfy, but I am not bothered by the pleather ones. Cup size is adequate for my ears, which don't hurt after hours of listening. I have had zero sweat issues either.
 
Sound
 
My first impression on putting on the Evo's initially was "Gosh--these sound pretty darn good." On VH's Judgment Day, EVH's guitar tracks sounded biting and rich at the same time. Still, the whole picture, all brought together, was somewhat muddy and muddled. Sammie's voice had little life to it and the bass was bloated. So, knowing about the burn-in recommendations for the Evo, I set it down and played random continuous rock/country/edm/jazz/bluegrass for about twenty-eight more hours. Then, I listened again. OMG--what a difference! Judgment Day this time had richer, fatter guitars, a snappy snare drum from Alex, and exhilarating vocals from Sammie. Onward. Pat Metheny's First Circle was a tour de force, with crisp, gorgeous vocals with multiple layers of richness and beauty, and just the right amount of bite. The acoustic guitar had punch and attack and clarity. The piano fills the track with percussive loveliness and sonorous layers. The bass is thick and rich, but not excessively so. There is harmonic detail in it. The soundstage is huge, with instruments placed in individual points in space and, at times, layered over one another. Detail retrieval is very good. When compared to my Sennheiser HD 202's, these Evo's are in another league. There is greater detail, a much better soundstage, and way more information delivered. The 202 is excellent for the money, but the Sennheiser veiling is quite prominent in it and listening to the Evo, I am more aware of this congested veiling because it is so absent in the Evo. It has a whole other level of stuff going on.  Cymbals sound like cymbals. Drums, like drums. Compared to the Crossfade m100, the Evo has slightly tighter bass, a more detailed midrange, and, to me, about equivalent treble. That's just me--others may feel differently. Lastly, I would say that the two areas I wish the Evo did better in are dynamics  (I listen to a lot of jazz and classical and the Evo could do better with dynamics, IMHO) and detail. This (relative to the absolute) reduction in detail can lead mids to seem slightly recessed at times. Compared to my Avalon Eclipses and Magnepans, there is no comparison in the amount of detail delivered. Still, for the money, they are remarkable. Just remarkable.
 
Summary
 
Summing up, the Superlux hd 681 Evo, Version II is a very good headphone and a terrific value. Do they compete with the best in the $500-$1000 range? Of course not. But they certainly do compete with many cans in the hundred dollar range (my v-moda were many times as expensive and I actually prefer the Superlux!). They are very enjoyable to listen to music on. That's all there is to it. Order a pair--you won't be disappointed.

I got those from thomann.de for 28€, shipping included
I own and am used to Sennheiser px-100, cx880, Etymotic hf2. 
I wanted to get detailed headphones like Etymotic hf2, but warm, and comfortable for longer period of time. 
After investigating many models, reading review & comparisons, and actually testing headphones on my own, I got settled with Superlux 681EVO White. 
 
With Superlux 681EVO i used:  -3db for 30-150Hz, +4db 1-6 kHz.. extra +2db for 4kHz additionaly
Those settings produce very balanced, yet worm and detailed sound. This makes every kind of music nice, but well mastered jazz and orchestral music is very impressive. 
Sound stage is wide and deep, with clear separation of instruments. 
 
Lack of  "airyness" compared to Etymotic hf2, but detailed, layered presentation that can be listened to for hours. (a half star is lost here).
 
I listen the music in flac form, from either my notebook or Samsung S4 phone, and everyset of headphones I own has their EQ settings that I use to compensate for their weak points. 
When used with velour pads, those cans can be worn for hours. 
Lack of isolation is both a good thing and a bad thing. However, I must sometimes make the sound louder in medium noisy environment.. (there goes a half star away). 
 
Conclusion - the music through 681EVO brings smile to your face. Is there more to be found? 

I'm still a newbie in the headphone category, just starting to try out all the hyped ones like SRH840, HD650/600 etc from the beginning of this year.
 
Now I'm left with this, HD600, and DT880.  I'm thinking which one of HD600 and DT880 to sell at the moment, so HD681 is certainly doing something right here.
 
In terms of absolute detail there's no contest here, HD681 looses, but for overall performance at such a laughable price, it's certainly a keeper.
 
Nothing wrong with the construction, plastic but yea, it feels solid on hand.  A minor complaint that it's not foldable, but with semi open design this is not for outdoor use anyways.
 
Comfort wise I find them very suitable for long hours of use(especially with the velour pads replacement).  To me they are just as comfy as both the HD600 and DT880.
 
Bass extends quite deep down there, quantity wise it's certainly boosted.  I don't find it bleeding into the mids though.  Certainly more bass heavy than HD600/DT880, but this makes HD681 more enjoyable for pop music.  Due to the bass, I will categorize the overall sound as warm(definitely more so than HD600/DT880).
 
Mid does its job, don't find it recessed.
 
Treble is just the right amount for me, less bright than DT880 but sounds like a tad more in quantity than HD600.
 
Sound Stage is excellent for its price, certainly feels more 3D than HD600 to me
 
As for source, they sound just as good to me with xonar dg and audio gd 12.1, which make sense as it's not the most revealing headphone.  Unlike the JVC S500, the HD681 does benefit from some minor amping, especially if you're going from a mobile source like ipod or mobile phone.  Pairs well with bright sources IMO.  A warm source/amp may make the bass too bloated.  
 
 
 
Overall, well... Can't think of a better deal than this in recent head-fi gears, maybe the Sony MH1C...

This will be a short synopsis of my findings after a few weeks with these. 
What they come with: First of all, they are shipped with a good deal of extras, including a longer studio-aimed cord, and a shorter portable one, a carrying bag, an adapter to 1/4 inch, and velour earpads.
 
How they sound: With velour earpads, a bit distant and tinny. With the flatter, normal ones, they sound more open and pleasant. It's a comfort for sound trade-off. I wouldn't say the sound very neutral or natural, because it is markedly V-sounding with hyped bass and treble. Closest sound I can reference is that of the ATH-M50s, except I prefer these - treble, albeit hyped, seems more authentic to me in the Superlux than in the M50s. (Be it said, the M50s I listened to were close to new). Excellent sound stage, very good implementation of the partial open-back design with 50mm drivers. Sound leakage is, as is to be expected, noticeable, more so out than in surprisingly. I use them as a quick reference in mixing, just to see if anything's blatantly wrong with the highs of a track, if I can't use my monitors (usually night work, when I can't really use speakers). They, together with my NVX-XPT100 (Fischer Audio Fa-003 clones), give a decent view of the midrange with the NVX and the bass and treble with the Superlux. So in a nutshell, tastefully hyped. Acoustic music sings on these, as do other genres to a similar extent, with tight bass and clear treble. Also none of the widely dreaded shrill sibilance in highs of the former HD 681s to report, nor are the highs excessively rolled off. Good balance.
 
How they're built:
They are of plastic construction, but none of it seems like it will give way. Flexible but sturdy, they should survive a fair amount of wear. The fit I found to be fantastic, the self-adjusting band at the top worked very well, and they do feel nearly weightless on your head, that is until you really forget that they're there and scrape them against a doorframe - as I said, they are somewhat comically immense. These are definitely for home use, or perhaps in a loud environment only because you wouldn't disturb anyone with sound leakage, but you wouldn't be hearing much either. These are truly best in a quiet room where no one takes issue with your taste in music. The velour earpads are also a great touch, they add a great deal of comfort, at the somewhat noticeable expense of sound. 
 
How they look:
Well, this is debatable. To some, they may seem pretentious, especially in white. Pretentious or not, they certainly do make a statement. Reminiscent in design to the SteelSeries Siberia v2 headset, these draw attention based on their looks and size. I have worn these in public, and they get a fair amount of comments. The most common is an incredulous face, followed by "what could you possibly need those for?". They are rather out of their element on the street, perhaps more because of the lack of sound isolation than of their size.
 
Verdict:
Brilliant, but hyped sound, in my opinion similar but possibly superior to that of the ATH M50s. They're worth M50 money as well, but cost a laughable amount. Insane value that I assume isn't yet generating noise because these are still fairly new, with few reviews on Amazon and not that much time on the market. Sound enthusiasts and even some producers can appreciate these. Obligatory disclaimer: yes, I realize that you cannot master with headphones. No one really should. But if you're still working on a mix, and have to keep it down, and need to check your treble for obvious issues, these do the job. Better, again, in my opinion, than ATH M50s (and the ATH M-lineup in general) and Sony MDR-7506, all of which I have had ample time with. Having said that, don't take my word for it, give these and some others a listen if you can and decide for yourself.

My old headphones that I used at work were starting to show their age. I started doing some researching online to see what were some recommended low-cost headphones.  I kept seeing the name Superlux come up but I had never heard of this brand before.  After doing some reading about the Superlux lineup, I decided I would try out the 681 Evo's since they address some of the issues the older versions had.  

When I received the headphones, the packaging looked pretty nice for such inexpensive headphones.  Then I opened the box and was very impressed with the build quality on these.   In my opinion they're not far behind my Sennheiser 580s in build quality!  

The head clamping force was uncomfortable for me but this is very easy to address.  You just stretch the headphones apart and then rubber bands that give them top headband it's clamping force, come unhooked.  After this, they are very comfortable to wear for hours on end. Even while wearing glasses!  However, my Sennheiser 580s are still more comfortable.
 
Initially the sound was very flabbily and boomy.  I broke them in with about 120 hours of non stop music. Then I played pink noise on them for around 32 hours.  The sound after this break in changed drastically for the better!  I use these on a daily basis plugged in directly into a Mac Pro's headphone jack. At home, I did try them with my Little Dot MK3 and found very little benefit to amplifying these headphones. I think they work very well without amplification.  
*****Addendum******
I tried these headphones plugged into my Macbook Air, and the sound quality wasn't as good as plugged into my Mac Pro or Little Dot MK3. So actually, these do seem to benefit from some amplification. I just didn't realize that there was such a big difference in sound output between the Mac Pro and Macbook Air. 
*****************

I paid $52 for these including shipping.  I've had them for a couple months and have no regrets.  The only thing is that mine didn't come with the extra velour pads. Eventually I'd like to buy some and try them out.  Right now, I'm very satisfied with these headphones and I'm in no hurry to modify them. 

These cans need cc. 50-100 hours burn-in time to give you the best performance. Their sound is very good for the price. In some cases I even prefer them to my girlfriend's Sennheiser HD-650 (you can buy ~10 EVOs for its price), because the EVO has a very natural, realistic sound, while the highs of the HD-650 are rolled back and it sounds a bit artificial to me sometimes. Unfortunately there were several reported issues with the cables, Superlux should pay more attention to fix these. My first EVO had a contact failure in the right channel, but my friend could fix it easily. The biggest problem of the earlier models, the piercing, hissing highs are fortunately not present anymore, the treble is clear and not fatiguing in the EVO. It works fine with some portable players, but has volume issues with others. The impedance is only 32 ohm, but the sensitivity is quite low. It is really bulky and looks stupid on the street. But for home use...
HIGHLY RECOMMENDED!

First off, this is my first review on this site and I'm by no means an audiophile(still a noob with this stuff, so take what I say lightly/offer suggestions)
I got interested in high quality sound about a year ago.
My first "real" pair of headphones was the ath m50 so I'm going to be comparing these to those and maybe a few other earbuds and whatnot that I've also picked up

Build Quality
Initially, out of the box these looked really good. They are detachable, and come with two cables out of the box. One is like 10ft(previously said 5, it's actually much longer.) and the other is shorter. The headband has bumps on the top like the akg701 but they don't bother me at all. They're very nice and don't drive into your head like the k701s. They have pleather earpads, probably exchangeable with dt770 velours. They don't rattle a lot, and only for a little while did they *creak* a bit when I moved my head around but much less than my m50s.  For 40$, heck for the full retail price...they look legit

Comfort
The comfort at first for these was very weird. I wasn't used to any headphone like this so the self adjusting headband was confusing but eventually I got that. Also, they initially clamped down pretty hard. The pleather pads really hurt my ears but when I moved them around and after a lot of use they are very comfy. Overall they have *slightly* less comfort than my m50s but less clamping force and they don't get as hot. I can wear these for hours with no problem.

Sound
annd finally...the sound
These are paired up with a simple fiiO e7

My Gosh. I felt like I robbed someone when I bought these for this price. Simply amazing.
At first, with no burn in out of the box these sounded pretty neutral. They sounded somewhat similar to my sennheiser 428s. However, something was missing, they were....congested.
The sound was all cluttered together and was "robotic" if that makes sense

With some burn in, everything changed.
The bass went DEEP. The instrument separation was amazing. Not only could I hear background sounds that I never heard before, I could hear them throughout the entire frequency response.

Now for the comparison on how they perform compared to the famous m50
Bass
Despite being semi open, the 681 evo has good bass response. There is no or very little mid bass hump, and the sub bass doesn't die down until about 25hz or so. They extend deep, very deep for what they are.
The ath m50 has more bass and is more impactful, but the hd681 evo is slightly more controlled. Overall, the winner is the m50 here
m50-fun, more wild and exciting, better for bassheads
681 evo-damn accurate. 
 
Mids
The hd 681 evo doesn't dip during the mids as far as I can tell. The m50 has a slight midbass hump and the upper mids can be veiled. They actually sound quite similar here. No big difference except the 681 evos represents high mids better and you can hear more with them because of the separation. 
Winner-681 evo

Highs
A lot of people complained about the original 681s about having ear-rape levels of treble. That's not the case here. The 681 evo highs are very present but they never cause fatigue. They roll off  longer than the m50. Not sure what that means but the m50 has "punchier" highs. You hear the hi-hats and cymbal crashes of the evo longer but they don't sound like sibilance nor are they harsh.
m50 has slightly harsher highs.
Winner-681 evo

Soundstage
no contest. The ath m50 holds up pretty well and the soundstage isn't bad at all. But the 681 evo destroys it here. When I was playing Bioshock infinite, at the loading screen it literally sounded like a 50s radio was sitting 2 feet in front of me playing music. I was shocked, I thought my fiiO e7 had unlocked and the sound was coming from my speakers....it wasn't.

Detail
When I got my little amp/DAC and paired it up with the m50, I was in sound heaven. The detail retrieval was excellent.
The 681 evos took it a tiny step further.
With the m50, I could hear tiny details otherwise inaudible
with the 681 evos, i could hear tiny details otherwise inaudible...throughout the entire song

overall, I am very impressed with these headphones. I've never heard or tried anything better. So I don't know how these would stack up to higher end setups. But for 40$, even for retail value they are great. The m50 is a better beginner headphone but they cost more. So if there are any beginners out there who can afford a simple amp/DAC(they rely on amping more than the m50), then you really can't go wrong

inthere-thanks, glad you liked the review. I'm surprised at how long it was in the end lol..0
Anyways, the 681 evo actually has impedance than the m50 but the decibel level is lower. It should work with the iphone but don't expect it to be fully powered. 

I'll confirm or deny for sure later. That's my guess in the meantime

EDIT- I just got the modi/magni stack. These seem even more detailed before which is remarkable. The difference is microscopic, but audible. Soundstage is even more impressive. I will check to see if my m50 improves even more than these did from the switch.
Oh and inthere...Sorry man but it is physically impossible to go back to the sound of an ipod with these lol. They aren't portable, and they'll look kinda silly if you walk with them outside
EDIT 2.0- After quite a few hours of listening, these are actually quite bright as a consequence of the amping/DAC. I do think that the magni amp contributes and magnifies the treble(pun intended). If you're using these with an amp, prepare for a treble peak. nothing too bad, but it's definitely elevated by a few decibels.
2.1-So dissapointing though...Because if I could reduce the top frequencies by literally TWO decibels, they would be absolutely perfect. And I really do mean that. Perfect. 

This was an impulse buy that turned out well for me! I was very pleasantly suprised by the sound these are able to produce. They have a fairly open soundstage, which provides a nice separation. The bass is abundant but not overpowering, the mids are present and if any frequency is recessed, it is the trebles. This isn't to say they aren't there or sound bad, they're just the least obvious.
 
These cans are a little bulky, upon looking in the mirror I look like I'm ready to pilot a fighter from Star Wars. They are pretty comfortable, plush pads and soft head band take care of that. And the detachable cable relieves any build issues I had.
 
Overall for less than $100 these guys will not disappoint. If you need a set of cans that will make desktop or home theater listening enjoyable on a budget, give these some serious consideration.

Being my first review on Head-Fi, I'd first like to introduce myself. I'm known as Project Collider; I play guitar among many other instruments and record often by myself and with my band.
I'm a previous owner of the HD681, HD668B, and the HD660.
 
First things first; what improvements have been made or setbacks felt from the previous HD681?
 
At first glance it is clear that Superlux redesigned the shape and feel with the evo's. They look, oh! so much better; they feel good on the head and light weight, but at the same time there is a bulkiness to them, not to mention the pads after about 20 minutes moisten your ears and head. I do reside in the Sonora, so I can't completely blame the moistness from the design.
Side note: the design looks like the icemat/steelseries siberia v1 headphones.
 
I've tried the Evo's on three different rigs since I purchased them. Even on my laptop, containing an okay audio card, these things really sound fantastic and are easy to drive with just the stock driver software. Now on my main rig, I have a top of the line RME sound card; I am seriously considering selling off a couple of my beyerdynamic and sennheiser headphones since I got these.
I can't find a reason why I would ever spend between $70 - $300 for headphones anymore; the Evo's literally match anything in that price range (with the exception of a couple closed headphones).
 
The sound stage is wider than the previous HD681, the sound produced is much more neutral than the HD681; almost if you were to mix the HD668B with the HD681.
That deep bass is finally felt with the Evo's and pronounced at that, but not overwhelming like you find with a very bass central headphone (Monster Brand among other garbage). 
I've found that I use these most for my guitar monitoring and am loving the change up. Unfortunately they aren't closed, but there is a closed version; just really hard to find outside of Taiwan.
I love how perfectly neutral they are; extending from the lowest bass to the highest treble and popping those easily forgotten mids into the full hearing experience.
 
In conclusion, there isn't enough positive things I can say about what Superlux has done with the HD681 Evo's, (Original name HD681 MKII, but was abandoned for evolution).
 
So, go out and buy these NOW!!! Audiohipster currently has both the black and white in stock.