Superlux burst onto the scene (well the bubble I live in anyhow) in last 2 years with a range of ‘bang for buck’ headphones that whilst a tad raw and with some flaws won the hearts over many a headphone enthusiast for its fantastic price to performance, particularly the HD668B in the headphone category. I tested the HD669 previously (closed back version) and whilst it was not my cup of tea I did see why so many raved about it. For the price, and we are talking $50 or less it was very hard to beat.

But that was the end really of my interest until recently when a unit of the new HD661 fell into my lap. Once again the promise of a $50 bang for buck beauty with great sq came to my mind but this time the look of the headphone is rather different and the marketing promise is rather more targeted. This time Superlux are giving us a headphone which is sleeker, better built than previous incarnations, better packaging and in all it does seem the company’s approach is indeed evolving into something much more sophisticated and mature.

But does it sound any good?


The Box

The Box


1M straight cable model#FD1YW
3M straight cable model#FD3YW
Gold plated 1/8”(3.5mm) to
1/4”(6.3mm) adapter
Cable clip

Compared to the previous headphone releases the HD661 takes it up a notch or two and gives the whole package a more professional make over with a nice little display window and a more subdued color scheme externally. Inside the box the headphones are nicely perched on top of the soft cloth red carry pouch which itself is stretched over the contoured insert. Behind the insert you get the extra cables, adapters and a nice little fastener clip to keep the cable securely attached to the headphone. Yes its a detachable single entry cable style headphone which I prefer myself personally.

Physical Build

The headphone itself is made of stiff plastic with very few visible joins and it does indeed look very polished for a $50 can. You can tell Superlux have taken their cue and inspiration from the Sony MDR-7506; the design of the cups are very similar indeed though both differ in headband with Sony opting for a leather traditional style headband and Superlux reshaping their 3D wing system from previous models into a sleeker / slimmed down version for the HD661. The Sony though has a slight edge in comfort (though a well worn 7506 I might add) than the stiffer HD661 and the clamp is slight looser than the lock-tight feel of the HD661. The clamping is pretty strong overall on the HD661, perhaps even too strong. It will ultimately depend on your head size and shape if you think it is too tight or too loose.

Another note of difference between the HD661 and the 7506 is the headband on the 661 is locked as in non adjustable which worried me slightly but after a few head testing we found that actually it worked pretty well. Sadly the HD661 cannot fold at the headband hinges like the 7506 giving it a bigger footprint than the 7506 for mobility. The cups on the HD661 can though swivel flat though not parallel with the band but perpendicular giving this tripod type look which is perfect for lifting off your ear when you want to suck in some of that outside noise.

The pads are also a tad stiffer on the HD661 but given the age of my 7506 this might be an unfair contest. Much like the 7506 the HD661 has slightly angled cups which might take a minute or two to get used to for those that normally wear their headphones ‘straight up and down’.

Do note mine came in black but you can also get in a range of 10 colors to suite your tastes including red, green, pink, grey/white, purple, orange to name but a few.

Overall I am impressed with the build quality of the HD661 though the slight edge in comfort goes to the 7506.

Sound quality


Acoustic Design Dynamic, closed-back
Driver 40 mm, neodymium
Sensitivity102 dB SPL (1mW) at 1KHz
Frequency Response 10 – 20,000 Hz
Maximum Input Power 200 mW
Rated Impedance 68 @ 1KHz
Earpad Leatherette
Head Band Pressure Approx. 4.5 N
Cable 1-meter(3.3 ft.) & 3-meter (9.9 ft.) straight cable, single-sided
Connector Stereo mini jack
Net Weight 190 g (6.7 oz)

Superlux HD661

Superlux HD661

Its not a 32ohm Grado style resistance headphone but its still relatively easy to drive out of a jack having tested it both with an ipod and a Hifiman HM602. A small headphone amp thrown into the mix gets the best out of it.

The first thing that struck me about the HD661 was that it was much more aggressive and open than the flatter 7506. The HD661 had a less recessed feel, more intimate than the 7506, placing you much ‘closer to the stage’ than the 7506. This more aggressive stance gives the HD661 a lot more initial impact and wow factor though for prolonged periods this might get slightly fatiguing on more treble intensive music such as Skrillex which was a tad too harsh for my liking. Mind you Skrillex is one of the most demanding dance acts in any headphone so this no deal breaker.

What is immediately noticeable with the Lux HD661 is there is a lot more treble response. Perhaps a little too much treble for some tastes and lovers of the LCD-2 sound would be best just moving along in that respect. This is not a dark headphone. In slower more mellow jazz and vocal tracks the treble works pretty well without any overt signs of sibilance. In fact move this headphone away from busy hard rock and metal and the treble gives most tracks a nice open sparkle.

Compared to the 66X series the HD661 is much better balanced and more articulate across the range than what I have heard previously. What is interesting to note is that compared to the 7506 the bass has a higher degree of mid-bass slam than the 7506 but I would term the 7506 as a bassier headphone overall. The slam on the HD661 is just yanked up a notch but after extensive listening to both I just felt the 7506 has a tad more reach the lower it went. The more intimate soundstage probably helps to give a feel of stronger bass response on the HD661. It just feels more dynamic than the slightly more sedate 7506.

All this gives me an impression that the HD661 is a tad more musical overall than the 7506. It does demand more attention from the listener with its more intimate presentation, livelier mids and treble than the flatter 7506; though technically the 7506 has a slightly more refined sq. I really felt it came into its own when played with a slightly darker source than the ipod such as the Hifiman HM602 with tracks such as Sade “Skin” sounding really articulate and smooth. If you are using an amp then I would pick a darker amp such as the C&C X02 over say an Ibasso which may accentuate the inherently bright and bubbly nature of the HD661. This headphone is built from the top down sound signature wise and it seems the aim is to perhaps match the 7506 across the spectrum but give it a more livelier and aggressive stance that makes it a much more involving experience than the 7506.

I enjoyed the HD661, I think it is great value for $50 and would recommend you try it out for yourself if you get a chance. Consider it the ying to the ATH-ESW9’s yang for a quick and dirty comparison. It burns bright has high impact and initial wow factor but might get a tag fatiguing after an hour or so of continuous play if your preferred genre is ‘loud and proud’ rock or hard hitting techno. The presentation lends itself very well indeed on laid back vocal tracks, jazz, classical and some areas of trance as well as R&B, well anything that benefits from a bit of detail to the presentation to be honest.

It is in my mind Sueprlux’s most mature headphone offering to date.

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12 Responses

  1. anon322

    Is this a better pick than the AudioTechnica SJ series? Especially the SJ-55? I currently have the SJ-11 + Fiio E6 combo and was planning to upgrade to the SJ-55 but this caught my attention.

    • headfonics

      Two very different headphones I think – the HD661 is more about balanced and brighter and the SJ-55 is more bassy and veiled and muted in the highs. The HD661 will have a better midrange than the SJ-55. Depends on your preferences and what your after. If you don’t like bright cans then the SJ-55, but if you prefer balance over bass then the HD661.

  2. Doyen Keaton

    Man got chance to listen to the HD-661 last night … and freak it sounds like sex to me… ear tease.. and got a chance to compare it to the 7506..  the 6 is bright light in the ass.. and not good for tracking and neither is good for monitoring… ( they will make make a bad mix sound good or not according to the real world )  but very pleasing to listen to… the 661 has better isolation but not as good as the 662 series when tracking. the 661 is louder then my worn out 7506… the 661 sounds better… more hype. over all.. but fatiguing to me after awhile if you our a loud listener…  i prefer the real world sound of the 681, and 662 series… over all the 661 is a super can and way worth the money.. and Marcusd great job on the in-depth review.    Doyen AudioHipster Recording Services

    • Anonymous

      Thanks Doyen for dropping by and yes my sentiments exactly – it is an attention grabber and well worth the money but lacks just a touch of finesse over the 7506 over longer periods. I think a job well done by the Superlux guys.

  3. asd qwe

    What is the soundstage performance like on the HD661 compared to the other open Superluxe headphones and the ATH M50?

    • Anonymous

      Personally with the HD661 you have a more up front and ‘closer to the stage’ experience in my opinion than the M50 and both being closed the sound stage is not that spectacular. Open headphones always stand a better chance of producing a bigger sound stage and will give you a more airy sq. 

    • Anonymous

      The ATH M50 is overall a better sounding headphone but of course it is 3 times more expensive. The M50 has smoother highs and much deeper bass (slam and extension). Tonality wise the M50 is a neutral can with great bass.

      As to which lux as the deepest base that is a very good question since I have only briefly tried the HD669 and the HD661. I think the HD661 is more balanced than the previous incarnations but the one with the most bass is probably one of their IEM’s, the HD381!

    • Anonymous

      Edmund of XTC should be able to help you out there pretty soon since the 661 is one on the list due to hit the shelves very soon.

      By the way I tested this using two setups, the more expensive one was the Cypher Labs AlgoRhythm Solo with ipod nano 5th gen running into Superlux’s very own HA-3D amp (3 jacks so great to compare without interruption). The second was the Hifiman HM602 direct into the HA-3D amp using the line out.


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