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Superlux HD-668 B

93% Positive Reviews
Rated #9 in Over-Ear


Pros: Neutral, revealing, precise, lightweight, sturdy, cable features

Cons: Strong clamping force (gets better with time)

As the saying in the title goes, this has never been truer than for these headphones.

Thankfully, Superlux sells sound quality, not an overhyped brand name. Can you really get great sound for $40? Oh yes, and it's right here.


I was recommended these headphones by a fellow forum member and after a day or two of investigation I decided I really liked what I read about them and figured if it was true, then these would be the best headphones I could buy on my really limited budget. So, I did.


Before I give any impressions, a small disclaimer: My previous headphones were Trust HS-6200 5.1 USB, and Trust Multi Function Headset 310. The most "hi-fi" component I have in my house is a set of Logitech Z-5500's. They run via coaxial, while everything else runs from the motherboard Realtek ALC889 codec (best Realtek codec, but still onboard.) So, I have not had much experience with quality components, but I know how to trust my ears. Hopefully, this will be enough to make a relatively accurate assessment of these headphones. Let's take it from the outside in.


Design: Well, the first thing that surprised me is that they are relatively small. I expected them to be a bit larger from the pictures. The next thing is, they are really light, weighing only at around 200 grams, which is good as it makes them easier to keep on the head for longer periods of time. The build is fairly sturdy and the plastic is of good quality, they look like they will last long. I'm not going to comment much about aesthetics, aside from the "Studio Monitor" labels being a bit tacky, but I generally like the way they look.


Comfort: A bit on the tight side. Causes my ears some discomfort after having them on for a while (upwards of 2 hours), but after a few minutes break it's good. I've read some people claim it made their ears sweat and heat up, I haven't had those problems but I don't normally sweat much anyway.


Accessories: With these headphones you get a 3m cable (for PC use) and a 1m cable (portable use) which you can exchange and even combine together. You also get a 3.5 (1/8") to 6.3 (1/4") mm jack adaptor, which is a nice feature, and a carrying pouch to, well, carry them around.

I liked the cable flexibility the most, I think it's a great idea.


Sound: And here we go, the most important part. I'll try to refrain from analyzing these headphones in the typical fashion here such as how the "highs, lows, mids, etc." sound as I don't think I'm familiar enough with the terms here but I will attempt to describe their overall sound signature with my limited experience, so here goes. What you play through them is what comes out. A bad recording will sound bad, a good one great. They are really transparent, simply "passing on" the sound without leaving a hint of presence of their own. And honestly, I like this. I want to hear my music the way it was recorded, intended to be heard. I don't want headphones to change my music. Sure, colored headphones may make it sound more "fun", but that's not the way the artist heard or made the track. Well, to each his own I guess. To continue: they reveal a lot of detail. A lot. Background hiss, noise, breathing, coughs from artists and stuff I have never heard before in my music. I have to play through everything again, to rediscover all those tiny details I missed out until now. The frequency response doesn't have many spikes, and it corresponds with what you can see on the manufacturer's website.

Soundstage, well, it's generally good. Certainly better than the closed-back headphones I own. These are only semi-open however. Sound isolation is still OK, I can hear myself typing and my noisy PC case, but when music plays it's hardly audible. To sum it up for the Superlux HD668B: Add nothing, reveal everything.


Oh, one more thing: the bass. I've seen a lot of people claim the bass isn't strong enough, while a few claimed the bass was good. And I believe I know why. It actually depends where you plug them in. If I plug them into my PC case's front port, the headphone out on the Z-5500, my cell phone or MP3 player, the bass is overwhelming, in fact there is more bass than there is in the 5.1 headphones that had a dedicated subwoofer inside, and it certainly does not sound natural. However, if I plug them into the rear ports on my motherboard where there is supposedly a headphone amp the bass tames down by around 80%.


EDIT: After a bit of longer listening, I've realised that it's not the amount of bass that changes. It's the amount of mids and highs. The thing is, the output ports on the back of the motherboard are assignable. If I set the jack to "speaker out" they give a line level signal, and the headphones sound substantially less clear and you have to turn the volume up from 35 to around 80; this gives the impression that the bass is louder - it's not, it's only that the signal is not strong enough to drive the mids and highs up to point. When switched to "headphone" setting, the headphone amplifier kicks in and the higher frequencies -really- jump up, leaving the bass behind at the "normal" level. This is why it seems it has less bass. So even though these headphones are only 56 Ohms, they certainly benefit from amping, and well at that. Line-level won't cut it.


Overall, I am extremely happy with them, will keep them around for a long time. My next purchase is going to be an Asus Xonar Essence ST, I can't wait to hear what they will do then. Well worth the money I paid for them and more, and would recommend them to anyone in this price range, for sure.


Pros: dynamic, deep bass, relatively balanced, analytical, good soundstage, very inexpensive

Cons: slightly recessed lower mids

I won´t repeat what everyone else wrote before - because it´s true. I´ve listened to a Beyerdynamic DT990 once and while I love my Sennheiser HD-600 a different cup of tea would be nice sometimes. But then, Beyerdynamic headphones are a bit too expensive for the sole reason of being able to listen to "another flavour". Thank God there is Superlux. You´ll get so much material for your money. You´ll also get very good, Beyerdynamic-like sound. You can even improve the sound if you replace the pleather earpads with the velour pads for the AKG K-240. I don´t know why but they sound a bit more balanced and refined with these earpads. Further improvement can be achieved by putting paper tissue between earpad and cup (increases the distance from ear to driver and will likewise improve comfort).


If you do these two things you´ll get a headphone that will rival headphones for 150-200 Euros: they are dynamic, precise, crisp, balanced with a very good soundstage. They are easy to drive but they will sound best with good amplifiers. They won´t be impressed by loud or harsh music, they will just play along with just the right amount of directness. Some people would argue that this makes them sound a bit "bored" - which sounds almost insulting to me because they are anything but boring. People seem to confuse balanced sound with boredom. Well, let me put it this way: if you want your headphone to colour the music you´re listening to... go and search elsewhere. The Superlux does indeed add a bit colour (around 7.000 Hz) but it´s not very much and it´s not distracting. However, lower mids seem to be a bit underrepresented - but I could be fooled about that because I´m accustomed to the comparatively (to the Superlux) warm mids of my HD-600.


All in all, very, very good for the money. A true bargain, thank you Superlux.


P.S.: before I forget... they need considerable burn-in time to sound their best.


Pros: Price, awesome sound quality for the price.

Cons: Bright and recesed mids

After a year with this amazing cans i think i can say a couple of things.


How the hell they can make this cans for this price?? China it's the answer...




This cans are amazing for only 20€, they do an unexpected sound quality for the price. It's not a Giant Killer but it's a Mini Giant Killer (MGK), i own a Sennhesier HD555 and -for sound quality- the HD668B are at the same level no doubt, but for 1/4 of the price. 

If you like the music and want to experiment audiophile sensations but haven't soo much money i can't imagine better 20€ on sound equipment. 


Audio Quality:


Taking appart the price and forgetting the price to loose the Hype i must to say that his quality sound it's good, at the same level of cans with my HD555. Differents sound signature but same quality level .


The very best sound of this cans cames when we burn in about 200-300 hours, recesed mid came more forward and don't miss it soo much, and the initial bright blows up a bit but don't dissapears. At his 56ohm and sensivity is not a requisite amplifier the HD668b to make it sound good but an amplifier make it push his best sound, resolution, instrumental separation, etc.

In other words they are more Mini Giant Killer with a good amplifier on the way.


It's supposed to be balanced cans for the B on HD668B but it seems to me it's not balanced flat, it's balanced on "V" like the Beyerdynamic DT990 -on the superlux website it's frequency response it's compared and it's very similar-, soo take in mind that, this cans aren't Flat at all.


This cans are very analitycal, very detailed with envolvent sounds and with a very good soundstage, all this make rediscover new things on music you use to listen; little sounds that wasn't before but appear with them, it's a good sensation rediscover your old music on it.

They are very transparet on the recording quality sound, if you find distorsion don't blame on cans, blame on bad recordings and mastering studios or the bad music quality music you heard. Most pepople says this cans are bright and i think it's beacause of it, if the recording it's bright the HD668b make you to know "screaming" to you :)


The bass its well extended and present, maybe a bit muted on the very low frequencys (20-50HZ) but much more present on middle low frequencys (50-150hz) and with a very funny punch on it. Many people will found it  short of bass but i think its the perfect quantity to feel it real and not overbass.

I found the punchy bass very very funy and enjoyable on it. But without amplification dont expect miracles... 


The mids are a bit recesed at first but after 200-300 hours it came a bit forward and you don't miss it anymore, unless you like very forward mids in that case you don't like it. They are very well balanced after the burn in, very detailed, with clarity and natural.


The highs are very very good for me -but i like crispy sounds!!-; some people found highs very very present on this cans and don't like it for this reason, it's a point to have very present on it. I think that the  bright highs dissapear a bit after the 200-300 hours of burn in but always be there.


The "timbre" it's not bad at all, is not the most realistic -my Sennhesier HD555 have a more crystalline "timbre"- but i like it soo much on cord instruments and female voices and acoustic concerts. Maybe not as realistic as my Senn but much more fun and enjoyable.


A good amplification cames to life many many things to this cans and make it a lot of better, don't miss this point. Not soo much ohms on the way but with his sensivity (98 db SPL) a good amplifier change many things.




Nothing to say that you couldn't see on the photos. They are a copy of AKG on design and Audio Technica on headband pads. They are really light, lot of plastics every where, but well built and support hard treatment on it without broke it. Mines has fall down many times to the floor and still survive!!!


The pressure on the head maybe its a bit hard to support many time continuisly on the head and hurts but with time it take the form of your head and will bee more confortable, but it's there.


The most criticable thing on this cans it's the ugly earpads that would you sweat on summer like an idiot, and maybe Superlux would take the point for next models... :)


They have a cuple of cables (1m and 3m), one jack adaptor 3,5mm to 6,3mm and a clip to swich with no problem the cable to headphone that it's a new great idea rom Superlux and would must copy other brands.




This it's a good cand, a very very good headphone for the price, i can't imagine a better 20€ expended on  sound equipment.


Pros: Neutral sounding :-)

Cons: Neutral sounding ;-)

I recently got these headphones from a german online store after reading the raving review at headphonia.com. While it left me quite sceptical, I thought ca. $35 isn't that much of a risk to take and they'd even be worth the price if they just had a decent sound quality.

But they haven't. They have an incredible sound, just like the reviewer at headphonia and the previous reviewer here have described it. They are very detailed, very much extended into both directions of the frequency spectrum and sound just wunderfully neutral. The highs are brilliant but not shrill or sibliant, the bass is punchy but not muddy and overwhelming, the mids are tight and precise - it's just everything there as it should be, nothing added and nothing left out. If you prefer a more coloured kind of hi-fi sound like the Grados are known for, these cans aren't for you. If you prefer a neutral, "honest" kind of sound, I doubt you'll get any better cans below $200. Personally, I love the synergy the Superlux show on a crossfeed. It "warms" up the sound just to the right amount, giving a slight boost in the bass and further refining the headphones convincing soundstage. I prefer that combo to most much more expensive headphones I know.

The only thing, however, that constantly reminded me of wearing a headphone was the pressure of the pads, which made my earlaps hurt after an hour. I solved this problem by adding a little spacer (made out of paper tissue...) to the back of the earpads. Considering the headphones quality it would also be worthwhile to replace the "pleather" earpads with some higher quality AKG ones.

Another detail I love about this cans: they come with two sturdy, detachable cables (1m and 3m, combined 4m) to ideally suit your needs. Great idea!


Pros: (in context of price) detail ,resolution, soundstage, fast-taut bass

Cons: (in context of price) bright ... bright ... bright

Got 2 pairs for US$65 ... gave one to a friend who is a bass-head (plays video games and runs it through movies [ DVDrips]) and kept one for myself.


After a year, here is our skinny on these El-cheapos:


Get the ugly part out of the way --> These boys are unforgiving and bright and WILL show up your crappy music systems. If the recording was brightly mastered/crap, if your source is bad, if your cables are bright (esp. pure silver and silver plated stuff), if your amp/dac setup is too revealing THEN these babies are RUTHLESS. They will show up the brightness and amplify the crap out of the brightness to make ears bleed.


No .. they will not flatter anything. They just let you know something is really amiss in your chain of music production.


Hence: although easy to drive (low impedance, high sensitivity), these are NOT for badly ripped MP3s, not suitable for porta-ipod/phone/mp3 players and not for your cheap PC music cards.  Forget it, you will get better sound elsewhere. You have been warned!!


Now for the honest truth about these phones - look carefully at the reviews. The folks who have a decent setup, and putting thru good quality sources (properly done CDs/FLACS/SACDs --> decent DAC --> decent amp) all enjoyed them, or were smitten by their price/performance ratio.


They may not beat the big boys costing 5-10X more in price (certainly not the Denon D5000 or the Grado PS1000). But unlike the other cheap crap in the sub US$100 range, they don't get worse as you up the ante, they get better - and better to the point of lunacy. No cans priced US$ 30 should be giving owners of Senn HD 600/Denon D2000/AKG 240/Grado 125 (Yes between my friend and I, we have had all these for extended periods in the past) raised eyebrows ... but this one does.


Yes its still slightly bright, and its bass doesn't extend low enough, neither is its midrange meaty and alluring enough ...BUT ... it IS still impressive for US$ 30.


Its best you treat these as studio monitors, as they were intended by their creators. But if you ever want a really ruthless pair of cans to weed out a weak kink in your setup, then try these out. If your systme boogies on these baby, then you can try out any other more esoteric headsets and have something to smile about.



















Pros: Very natural, transparent, accurate, fast sound, fairly comfortable, nice looks

Cons: Headband can press on head a little and tight space for ears in earcups

These headphones don't seem to add anything to the recording. It feels like they have absolutely no color of their own. Good recordings sound incredible good! Mids are delicious but not overly emphasized like in some phones. Bass is not weak, very strong actually, and it goes deep, but it's volume isn't too loud. I use a little EQ to give bass a boost. Highs are best I have ever heard. They are delicate, soft, not too bright but still very accurate. And they extend really well. 

I am just listening to music with these, not headphones. These are very detailed headphones, so every nuance in original recording and source comes through. The soundstage is very realistic.  


Build quality felt a little cheap at first but the excellent sound quality makes up for that. Headphones are very lightweight so they should be comfortable. The auto adjusting design means that the wing pads press a little to my head. I need to keep breaks after two hours of listening. 


These are very cheap headphones but that is only a huge plus. If you want to have quality sound and also pretty comfortable phones then pick these! If I wanted better audio quality I should prepare to spend 10x the money these cost! 


Pros: About Everything

Cons: None

Amazing Headphones.


I 1st found out about these cans when I walked in on a new audio shop in our local mall. They had a lot of cans and IEMS available for audition so I listened to one. I was blown away with the detail and just about everything, there are also some Sennheisers there but these really stand out for me I couldn't put them down. My first thought was these must have costs more than those Senns but when I asked the salesman he told me it only costs around 40$. Wow! Really? So I researched about the brand and found out it was really praised very well here and other audio sites. Long story short, I bought 1 the next day.


Pros: Sound- bass, treable, mids, stage accuracy

Cons: Not very portable, pleather cushions make you sweat when is warm..

Killer headphones for the money.  Very hard to dislike. People who probably paid more money for AKG K240's (which sound inferior) would probably criticize them. I work in the audio retail industry and have experience with Grado - full line, Sennheiser - full line, AKG full line, Goldring, Beyerdynamic. 

There is definitely something magical about their sound that makes me return to them again and again even though my collection includes: Sennheiser - HD600 and 250II Linear, Beyerdynamic DT990pro, 770 - 600 ohm, AKG K240 - 55 ohm, Grado SR80 and I-Grado.

I have to mention  that I did few mods: First I removed the thin black fabric from the enclosures and replaced with organic cotton pads one for each side.  Second I replaced the logo plastic caps with wooden ones and third I cut felt pieces and replaced the bass pads that cover partially the drivers (mine cover tiny bit less)

I listen mostly classical music, jazz. I also listen some 70's prog rock, acoustic rock and electronica. I listen analog or uncompressed digital files (SACD, 24/96, 24/88.2, 16/44.1)

I don't know how MP3 will sound with the HD668B .  I use FLAC on my portable player and the sound is pretty good. People who are complaining about comfort should listen Grado SR60 for couple of days and switch back to the HD668B.

I think the HD668B are killers for their price and Superlux is a great company which makes affordable products with great sound quality.  Now enthusiasts and professionals who couldn't afford to buy 5 pairs of AKG's for their studio can do that with Superlux without compromising the sound.


Pros: Feels solid, can play very loud, comfort, detachable cable, good value

Cons: exaggerated bass and treble, sibilant, looks a little cheap

I got my hands on an HD-668B today...

I still wonder what's up with these AKG clones... Is Superlux paying license fees to AKG so they may use their classic K 240 design for their headphones? One could certainly think so since a reputable dealer such as Thomann in Germany is selling them and they probably don't want to anger the Harman group :-)

Let's have a look at the headphone itself...

The earcups' construction certainly looks a lot like AKG's K 240 design that has been around for ages. On this one, the outer headband is a little different and instead of an inner headband, it has "wings" with cushions that rest on the head.

The build quality and materials feel pretty solid but look a little cheap compared to a real K 240 (though not bad for the price!).

The vinyl earpads seem a bit thicker and more dense than AKG's. This may not be such a bad thing as the baffle of real K 240s tends to press on my outer ear after a while. Real AKG vinyl or velours pads can be used if desired.

The cable is detachable and the headphones come with two cables that are 1m and 3m in length. This is a nice touch, especially since the two cables can be combined, giving you 3 lengths to work with.
I don't, however, like the "connector" on the headphone that much. On the left earpiece, there is a thick piece of cable with a TRS plug attached to it. Since the connector on the earpiece is flexible, it is likely that the wires inside will break after prolonged use, thus requiring soldering. This does defeat the purpose of having a detachable cable in a way.


I'm giving the headphones only one star for "design" because you can hardly call it original.

So... how do they sound?

These phones have been called "giant killers" but I'm not sure I'd subscribe to that theory.

Compared to a K 240 Studio, the 668B has more bass and treble. While this isn't totally excessive, I wouldn't really call this headphone neutral. The treble response tends to make sibilant recordings sound a little unpleasant and I would prefer a flatter bass response (in fact I prefer a K 240 DF to the Studio or Monitor versions).

Due to the somewhat exaggerated bass and treble, the midrange suffers a bit and voices can sound a little thin.

All in all, the sound isn't too offensive, though and the headphone seems to be able to play really loud with little distortion.

As always, take my description with a grain of salt since your HRTF or head shape (or taste) may vary :-)

I'd say for the € 30 they cost around here, these phones aren't half bad. At less than a third of a the price of the K 240 S (still available in some shops), I think they're a good value.

Would I get one for myself? Probably not, since I do prefer a more neutral sound and I also like the quality and full spare part supply of real AKGs.

People who are not audio geeks or who don't mind a "fun" sounding headphone will probably be quite happy with the Superlux.


I find it a bit hard to translate my opinion of these phones into a star rating.


I think 3/5 for audio quality is fair since there is definitely room for improvement.


As an "overall" rating, I also can't really give it more than 3/5 since I wouldn't personally buy it.


I think for value it does deserve the full score since the user does get a solid product for a pretty low price and most people probably don't mind a little bass and treble boost at all.




Pros: The sound quality rivals $200-$300 mid-fi reference phones; neutral sound; clear; easy to drive; less than $50?!

Cons: plastic body, cables that come with are less than stellar, puts pressure up top of head with ATH wing design

Let me start by saying I don't normally write reviews on the official level, star system with graphs and all. I do look at them religiously when trying to find info on a HP, DAC, or AMP that's sparked my interest. So here I am reviewing on the Taiwanese made Superlux 668B which is quite obvious a mix of AudioTechnica's wing headband system, AKG K studio series body, with Superlux's driver. Aside from the last bit, obviously all are homages or clone of their respective brands. Not the first time one brand took from another however.

With that out of that way, let me start by saying at less the $50 shipped, not much can go wrong. The headphones look and might feel somewhat cheap on the cups but before you judge, plug the sucker in and have at it.


- Quite obviously the headband's wing system is something you'd find from AudioTechnica's line. Similar to AD900X and the likes. The headphone feels quite secure but the the two wings takes time getting used to. I'm hoping with time they get somewhat softer and less obvious. Aside from the two wings pads, the headphone is very light and does not feel like you're wearing a headphone at all. Clamp force is very good in gripping your head but not overly where it hurts (like a DT880 Pro when new). I've tried pointing my head downwards to try and get the HP to fall off, doesn't even budge. For reference I wear a 7 5/8" fitted hat, I fare on the big noggin side.

- The cups are made of plastic, they feel and look cheap. Aside from the opening of the grill, the cups look exact clones of the AKG K studio series (K240 for example). From the way the cups swivel up and down on the driver housing, the way the headband goes into the housing, as well as cable entry and run from one driver to another.

- The earpads are pleather and aren't too bad, although I can see some Hifiman velours or similar would do great on comfort. As is, it's not too bad. They're soft but not memory foam or anything fancy. The feel isn't too bad either, I've seen worse.


Now the most important part, SOUND.

They've been running for about two hours now and there's already a noticeable difference in treble. At first it sounded rough and spikey but after 60 mins it's calmed down quite a bit. From word around here, 50 hours would produce the final sound after burn-in. First these are what you would call reference type headphones, neutral sounding and fairs to the bright/airy side. No dark stuff here and if you seek a bass-head or a warm phone, look elsewhere. What I can say however is the clarity on these phones are fantastic. Dry sounding, it pairs well with tube amps for a more musical flavor but does well with solid state if speed and attack is of priority. With an emphasis in the treble end, they air on the bright side  The treble does get too hot with poorly mastered tracks, definitely a bright and airy phone that does well when the music fed is greatly recorded (loud war tracks need not apply). The bass has a steep roll off after 60hz, sub-bass rumble is non-existent but bass is pronounced from 60hz and up. Nothing sloppy, but unamped the drivers can lose control when the sound swells. Soundstage isn't very wide, I would say comparable to the DT880's semi-open width. Instrument separation are great, you can easily follow different instruments in a piece without it getting lost when you've got 3-4 different going at the same time.

These sound to be about 85% straight from a cell phone, a plus if that's all the source you have or need to use it on the go. When amped, the HP can keep things tight and true. It doesn't take a whole lot to get these going as well, plugged straight to my Lenovo laptop I'm having to use 50% of the volume bar to keep things at a sane level. These are 56ohms with the rating of 98db/1mW according to the box.

I've never heard anything in the full size realm that sound like these at this price range. It definitely holds up to the hype and praises it gets as reference or studio quality. If you prefer a bright tilted phone with a dry and clear sound at less than $100 this is something that should be in your shopping list. At the normal price of around $40, these are a steal of a headphone. It's great as a value minded HP, backup, or something to let the kids chuck around. I'm one for great value and willing to spend the money if it warrants it so when something with great value comes around it definitely sparks my interest. If you're looking for something that won't leave a hole in your wallet that will compare very to mid-fi headphones, this is it. A definite listener's headphone, not very show worthy but when your friends ask what you spent on it, you'll look like you've done some homework with your purchase.

Superlux HD-668 B

Superlux HD-668 B studio headphones, dynamic, semi-open, 98 db SPL, 56 ohms, 10-30.000 Hz, 300 mW, self-adjusting headband pads

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