Superlux can be said to be one of the best headphone makers for the lower end markets. They may not have the best looking headphones, but definitely they have the sound that can easily rival others in the price range they are selling. Now the Superlux are gaining popularity in the international markets thanks to their HD668B and HD681 which is the first two most highly praised headphones in the audiophile markets. They even have release quite a few new models which gains popularity very fast. The model that is going to be reviewed here is one of their most highly regarded models in their lineup which is Superlux HD668B.

Specs

Type: Dynamic, semi-open
Driver: Ø50 mm, neodymium
Sensitivity: 98 dB SPL (1 mW)
Frequency Response: 10-30,000 Hz
Max. Input Power: 300 mW
Rated Impedance: 56 Ω (Copper-coated aluminum wire)
Ear Pads: Leatherette
Cables:
1-meter (3.3 ft.) & 3-meter (9.8 ft.) straight, single-sided;
plug-in cable on headphones (mini stereo connector)

Connector: Gold plated stereo mini plug
Headphone Caliper Pressure: Approx. 3.5 N
Net Weight (without cable): 222 g (7.8 oz)

Designs

The design is a hybrid of both AKG K240 and the audio technica. The similar outer designs between the AKG K240 makes other thinks that this is another china copycat that just copy successful brands. But this is not the case with the Superlux Hd668B because even if they share the same housing designs, their speaker drivers are totally different. Superlux also state it themselves that by spending lesser cost in designing the housing, they can focused more on the main thing that make a headphone sound goods which is their speakers. They use a 50mm Mylar Speaker designs which is specially tuned and design by them. This is the part where they don’t copy other manufacturers.

Audio Technica Wing Headband

Another similarity with other manufacturer is the similar wing headband design in audio technica’s products. It might look the same but the designs on the superlux are poorer in quality. They still get the job done by fitting a wide range of head size without the needs to adjust the headphone.

While they look terrible and cheap on the outside, they are designs to hold a lot of rigorous torture from the users especially on a studio environment. They use a high grade ABS plastic that can withstand both heat and torture better than many plastic materials used by other well known bigger brand that always have reports of broken headphone. This is because most users are putting too much stress on the plastic headband, cup, headphone joint and many other areas that are more sensitive to breakage. In other words, this headphone looks and builds like a tank in which they can withstand a huge amount of torture while at the same time doesn’t attract people’s attention because of the ugly looks.

Another benefit from the copycat designs is that the earpad are interchangeable with the AKG K240 if your earpad starts to wear out or when you want to improve the comfort level or doing a minor change in the sounds. (AKG K240 has two type of pad that is reported to have different sounds) The downside in this is that the pad for the AKG K240 can cost as much as or even more than a brand new Superlux HD668B.

Partial Tissue Mod

The mod that I’m using now is a partial tissue mod. This mod is meant to increase the comfort level and is not for changing the sounds. There are many mod available on the internet including mod which removes the foam removal mode by removing the foam pad on the driver, full tissue mode and many more that are meant to changes the sound signature. Here are some of the modes available on the internets that are meant to make certain changes to the sound by following this link. Although most mod change the sound to certain degree, I still prefer to retain its original sound thus I make a partial tissue mod to improve the comfort by a small degree while still retaining the same sound. This is why I don’t opt for the full tissue mod despite the fact that can improve the comfort by higher degree but the side effect is changes in the sound signature which is something that I want to avoid.

While the sound of this headphone is really extraordinary, some mod is still necessary to improve the comfort especially on the part where the foam pads touch your ears. After a few hours of use, you will start to feel the pain the tips of your ears. After doing this mod, I can use it much longer while reducing the pain from the foam touching the ears. This is the biggest issue with this great sounding headphone. The comfort level just couldn’t match those more experienced or better known headphones brand.

Another issue in the comfort level that has been reported is the tight clamp on the head. This part is easier to overcome and does not require the users to use mod on it. What you need is just to find a proper size item such as a basketball or a stack of books that is wider than your head. Let it stretch for a few days to week and test it once it a while to determine the comfort level for you. Once it is well stretch, you can start using the headphones without much issue on the clamping factors.

Sounds

Superlux HD668B has more bass body, fatter and slightly longer in decay than DT880 and has more midbass punch than both the DT880 and Shure SE535. It is still not up to the basshead level yet but it is still enough physicality in the punch to satisfied most people. The midbass are so punchy until you are able to feel the impact of the punch in your face. This is most probably due to the 50mm Mylar Drivers which is considered quite large for standards of headphone within this or maybe even slightly higher priced range.

The sound signature is on the balanced side where that I find it to be the most ideal sound signature. The sound signature is even more ideal and better than those found on higher ends such as the DT880 and and Shure SE535. That is what gives me and possibly even others the impression on why this headphone has been a crowd favorite even against those that are much higher priced than it. This helps give the impression of a properly tuned sound and balanced between clarity and bass. The frequency response is emphasis on midbass to lower mids and then a drop from the mids to upper mids region which I believe some have referring it to recessed because of how it interacts with the female vocals. After the drop, the frequency is boosted back again in the treble area which gives it the impressive clear sound and details that you heard on this can.

Most of the clarity and details from this headphone is done through boosting their treble level or known as a treble boosted details, but I’m not sure why the main focus of the clarity comes from the mids instead of the treble. This is the part that I do not understand how they design it. Comparing it to their brothers the HD681, it is very noticeable that it is treble boosted. But when you listen to it, the biggest amount of clarity and details came from the super clear mids that do well with both vocals and mids instruments.

There is nothing in this world is perfect so does the Superlux Hd668B that sounded as if they are the perfect pair of headphone. They are in fact having a very nice and musical tone but the boost in the treble regions makes this headphone sounded a bit harsh when compared to those higher end models. The lack of a smoother sounds found in the more expensive headphones is the area where they lost. Don’t get me wrong here as there are many people comparing this with grado and alessandro headphone and found this headphone to be more smoother in the high peaks of the treble regions than those headphone. So it is still smoother and if you don’t really have any headphone to compare, I believe this could be your perfect benchmark for future headphones. Besides the more harsh sounds, they also loose in area that they are unable to produce more instruments notes at the same time that only headphones and IEM in the $300 and up range could produced. So this part is not a total lost but it should still be noted in case if you are wondering how this $30 headphone can compare to a $300 range headphone since I suggest that this is a tough challenger for the $300 range headphone.

Other than those two weaknesses, you can say that this headphone really could put up a tough challenge against not just headphones that cost one or two times the price but even against the headphones that are in the region of $300. They are in no way going to defeat the higher priced headphone, but the frequency response really could give them a scared and back to their drawing board to analyze what mistake they have done. I believe more headphone should be tune in a similar way to make it more interesting. It doesn’t have to match the exact frequency response but just on how they presents the music is something that other manufacturers should learn from.

On genre bandwidth, I find the HD668B to be more universal sounding than both the DT880 and Shure SE535. Although I’ve heard people reported that they work best with classical, I believe it can handle more genre than just classical. They can handle beautifully on just any genre including jazz with both the brass and wind instrument. On the string instruments, pushing the high notes such as piano’s high note may not be the best sounding. The warm sound still plays better with the brass and lower notes. This again shows that the treble is mostly used for bringing out the clarity and doesn’t mean that they do very well in the highs. Metal, fast rock and anything that requires a very fast speed and lots of treble at the same time should be avoided. Genre such as electronic, dub step may also require a more specifically tuned headphone. It can still play well with the electronic and dub step genre but the Superlux HD668B is unable to find the right matching with the sound. So this headphone is really my favorite for everyday use when I don’t need the more precise and refine sound.

Besides that, Superlux HD668B is also suitable as a reference headphone when testing your setup because I find it to be able to change the sounds accordingly to the sound system throughout my reviews. This is something that is very interesting because even some higher end headphones also don’t have the ability to change sounds according to the setup being used or in other words they have a fixed sound. They can be used without an amplifier but with each better amplifier, the improvement is very noticeable. It really scales up well even when paired with the expensive SPL Auditor amplifier. An amplifier is still required to get a proper sound out of it, but that can wait until you have the budget to add in an amplifier. So it really is a very budget friendly headphone.

Just like its original intention, the Superlux HD668B is really suitable for the studios mixing that are on a tight budget. The quality of the sounds really is good enough for you to hear all the details you need in mixing your songs. You won’t be missing much from those higher end models. The way it is tuned also sounded like a studio headphone. No doubt that it can be used for mixing your tunes and also audiophile users alike. The semi open design may not be too suitable for the recording artist because it might leak some sound into the mic.

In the end this headphone is suitable for which audience? Well I would say it is suitable for the people who do mixing in their house that are on a tight budget or looking for best value headphone and the audiophiles and non audiophiles who value clear, clean sounds with lots of details but doesn’t have the budget for a higher end models.

Price: US$30-60/ MYR150-190

Source: Govibe DAC, Hifiman HM602, iPod Classic

Amplifier: SPL Auditor, JDS Labs cMoyBB, Hippo Amp

Headphones: JH16PRO, Shure SE535, DT880, Crossroads Woody 2