Hey there everyone. Today we’re reviewing the new Superlux HD672 semi-open headphone. In the world of budget headphones, this is about as good as it gets. Whether used for pure listening pleasure or an extremely affordable studio monitor, the HD672’s sound quality is simply outstanding.
Many audio fans will be familiar with some of Superlux’s past products, like the HD668B (review here) and the HD681. Some people (including me) have been waiting for a long time for their new models, the HD671 and HD672 to come to market.
Well, that time has finally arrived. But there have been some design changes that many will likely find upsetting. Things like the new silicone earpads and the fixed cable, for example. However, if you’re willing to look past those things you’ll be rewarded with an absolutely stellar audio experience. Let me walk you through it.
This sample was provided for the purpose of an honest review. All observations and opinions here are my own based on my experience with the product.
Driver: 50mm, neodymium
Frequency Response: 20Hz-20kHz
Sensitivity: 95dB (1mW)
Connector: Gold-plated 3.5mm stereo mini plug
Cable Length: 2.5m
Headphone Caliper Pressure: 3.5 N
Package and Accessories
Just like the HD668B, the HD672 comes in a simple but robust cardboard box. There is an image of the headphone on the front along with the claim “Simple, Light Weight, but extraordinary”. Over on the back is another image showing both available colours (black and white), plus a list of features and specifications.
Inside, the headphone is presented simply, secured by a cardboard insert. The bundled accessories consist of a 3.5mm – 6.35mm stereo adapter and a storage pouch. At first, I thought my box was missing an additional cable (the HD668B came with 2 of them) but then I realized, with some dismay, that the HD672’s cable is fixed i.e. non-detachable. However, the attached cable is quite good albeit rather lengthy at 2.5m. This is good for home use but won’t be at all practical for portable use.
Build Quality and Design
The Superlux HD672 is only available in black in the US. In other parts of the world, it will be available in black or white and with a choice of 5 different coloured earpads (grey, black, red, pink and blue).
Two flexible spring steel rods make up the main structure of the HD672. These rods attach directly to the earcups, very similar to what we saw on the HD668B. There is a solid plastic joint partway down the rods that adds solidity and prevents the two rods from separating and thus creating pressure where they connect to the earcups.
The HD672 has a more traditional type self-adjusting headband, the same as the one on the HD681 and HD681EVO. Embossed into the top of the headband is the Superlux branding.
The earcups look similar to the ones found on the HD681EVO. They’re made entirely of a sturdy and lightweight plastic. There are 3 large slits acting as vents and just inside of those is a perforated section that surrounds the centre part of the earcups. The earcups pivot slightly to automatically adjust to the shape of your head.
Now, onto the earpads which are sure to be a matter of contention with many users. Rather than the traditional type that most of us are used to, the HD571 adopts silicone earpads. The earpads are made from a single thin sheet of silicone that wraps around itself to form a hollow interior.
The reasons for adopting this new style of pads are perfectly reasonable: they’re easy to clean and maintain and they won’t deteriorate over time like protein leather does when it starts to flake and disintegrate. They’re softer than the old pads so they form a better seal and are more comfortable for those who wear glasses.
But it’s a big change and comes with a fair amount of risk as people are likely to be wary at first. They are detachable though, meaning you can replace them with third-party pads if desired. So are they comfortable?
Comfort and Noise Isolation
The clamping force created by the flexible spring steel rods is minimal, so the headphone doesn’t press in uncomfortably on your head. The headband is very thin but I found it to be super comfortable on the top of my head. In fact, unless I’m consciously thinking about it, I completely forget that it’s even there.
Of course, everyone will be curious to know about the comfort of these new silicone earpads. For the most part, they are very comfortable indeed. The silicone is softer than the foam pads on the HD668B and there’s nothing inside them except air, so they conform more naturally to the shape of your head. The only caveat is that the silicone heats up very quickly indeed, so your ears can get rather warm.
There is one other major factor that will determine your comfort level with this headphone and that is the shallowness of the earpads. Just like all of the other Superlux models, the HD672 has shallow pads. However, unlike the HD668B there is no sheet of foam padding inside, so if you have larger ears they might be pressing directly against the hard plastic driver covers. This bothered me a bit at first, but after a couple of days, I stopped noticing it and now can comfortably wear the headphone for hours at a time.
When it comes to noise isolation, the HD672 has almost none. It has even less than the HD668B so you can still hear the TV or people talking in the background. Of course, this problem is not unique to this headphone and for most of us, it’s a worthwhile tradeoff to get that vast and open soundstage that only an open-back design can provide.
Fortunately, noise leak is actually not bad at all, so people around you won’t hear too much of your music unless you’re listening loud enough to damage your hearing.
The Superlux HD672 has a very balanced sound signature that leans towards neutral. Its clarity and detail are superb, as is the tight bass, accurate midrange and crisp, non-fatiguing treble. Despite being quite neutral, the HD672 is not in the least bit boring to listen to. Actually, it is an extremely musical and enjoyable headphone that impresses me more and more with each passing day.
In a word – tight. It has a wonderful ability to carry authority and weight yet still be conservative in terms of quantity. This adds body to the overall sound and warmth to the fundamental tonality of the headphone. The mid-bass is very well-defined because of its fast speed but it has a very natural decay, lending realism and tonal accuracy.
The HD672’s sub-bass is also conservative in quantity and has a fast rumble with very good extension. In “Echolon” by Leech, the intermittent sub-bass note is rendered beautifully by the HD672. The headphone flexes its muscles and leaves no doubt about its ability to bring the rumble but in no way does it infringe on the clarity of the midrange. To summarize; the HD672 plays bass like a master.
The midrange on the HD672 has exceptional clarity and good resolution. The timbre of instruments and vocals is fantastically accurate and it’s easy to see why people might consider this for use as a studio monitor for mastering and mixing audio.
Vocals have good density and sound very lifelike, as though the performer is standing in front of you. “Ariel” by Anathema is one of the tracks I like to use for testing because on a lot of headphones the vocals can sound quite grainy and strained. That wasn’t the case here ~ the HD672 handles the male and female vocals with ease and even though the clarity is so good, it still manages to be smooth.
When I say this headphone is neutral you might get to thinking that it is also dull and boring. That simply is not the case. Yes, it is accurate but it’s also emotive and has a great dynamic range.
The treble is crisp and detailed delivering airiness and sparkle to the mix. It’s not only very clear but is also mercifully smooth. That is to say, it’s not harsh nor sibilant, however, it does not mask any inherent sibilance in recordings.
Similar to the bass, the HD672 is fast in the treble, showing good transients and excellent definition. It does not come as a surprise either, that the treble timbre is very accurate, just as is the rest of the frequency spectrum.
Being a semi-open back headphone promises a sizable soundstage and here the HD672 does not disappoint. It presents a very open feeling stage that is not necessarily expansive but is incredibly natural and unforced. Note density is in no way sacrificed and the imaging and positional cues are outstanding.
The headphone is able to create perceptible layers on the stage, showing an adept manipulation of depth and height. Vocal positioning is excellent, resting at the centre of each ensemble. Width in the music is not sacrificed either. The HD672 is able to project sounds outside of the headspace and surprisingly the depth of the headphone seems to reach just as far as its width.
Superlux HD672 vs Superlux HD668B ($35 USD)
Most notably, the first difference I picked up on is that the HD672 is easier to drive than the HD668B. Despite having a lower sensitivity, the HD672 also has a lower impedance of 32Ω compared to 56Ω on the HD668B.
The HD672 has less midbass but just a bit better definition. The difference in quantity is very slight. Sub-bass quantities are similar too but the HD672 has a hint more extension and texture.
It’s more in the midrange that the HD672 shows its superiority over the HD668B. Vocals are positioned more forward, with better articulation on this newer iteration from Superlux. Clarity is better than that on the HD668B, thanks to the HD672’s superior treble notes and extension. This makes the HD672 sound a touch brighter than its older cousin and the rewards are better separation and detail throughout.
When it comes to build quality there’s little separating these two headphones. Both are extremely lightweight and robust. Both are made entirely from plastic except for their spring steel rods that form the arch.
So which one is more comfortable? Well, even though the HD762 has less clamping force and softer pads, I would have to say the HD668B is more comfortable. The only reason for this is the thin sheet of foam it has inside the earcups that your ears rest against. Apart from that one detail, there’s really nothing else to separate them in terms of comfort.
Superlux HD672 Conclusion
I have to admit that at first, I wasn’t impressed with this headphone and there were 2 reasons. The first was the silicone earpads. We’re just used to protein leather or genuine leather covered foam and anything else feels alien to us and takes time to adjust to.
The second reason was the fixed cable. Being able to choose which length we wanted to use with the HD668B was liberating and also made it feel like you were getting more value out of the box.
As time went on, those 2 things became less and less of an issue for me. My ears and brain adjusted very quickly to the idea and the feel of the silicone pads. The cable still bugs me a little bit but only when I think about it. The HD672’s 2.5m cable is okay for the desktop and would be ideal in a studio but it’s not at all good for plugging into a DAP and moving around the house.
Regardless of all that, I’m here at the end of my review and I have a deep respect for the Superlux HD672 and the more I listen the more I’m impressed. This is easily the best headphone I’ve heard in this price range. Sure it has some unusual features and how the public reacts to those will largely determine its success in the long run. But I truly believe that if you’re willing to give it a chance, you will be delighted by what you hear.