Accessories: 1m cord, 3m cord, 1/4" adapter, cable clip
On first glance, the housing looks cheaply built and dull. However, in real life it feels solid, yet light at the same time. It uses the same wing design as Audio Technica, with an AKG design on the cups. It's lighter than the M50s, which is built like a tank and feels like one too, though the HD668B is heavier than the HD681F. The material feels very nice and sturdy. Definitely not worth $50 with the amount of work and materials used in these cans...
Sits very nice on my head. Clamping force is tight, but not overpowering. Keeps the drivers nice and close to my ear
SQ sounds very Beyerdynamic. Light bass accent with amazing detail retrieval.
Highs sound... how to say... grainy. Not overly grainy, but with high frequencies the graininess is noticeable. A little honky and weird at times, and considered "unlistenable" to some people I know.
Pretty distanced and not too in-your-face. Electrical guitars sound amazingly smooth, acoustics sound clear as crystal. One peeve about this aspect is that it could be a little more forward. Not too much, but enough to hear the air in the strings
Reaches down nice and deep. The quantity is there, though definitely not for bassheads. Clarity-wise, it's tight and quick. Reverb does exist, but in low quantities and only in the very low frequencies.
VS Audio Technica M50
Famous as one of the best beginner cans around, the M50s have been praised for being analytical with a fun side.
To my ears, even though the HD668B does not have the same detail pickup in the treble regions as the M50, they are sharper (is that the right word? Opposite of warm anyway) sound, while the M50s has a slightly more lush and smooth sound, better for vocals and wind instruments. Graininess on the HD668B is definitely more prominent that on the M50s, and sound a little hissy as compared to the pretty grain-free treble of the M50. Layering on the M50 is also superior.
Verdict: Probably the biggest flaw in the HD668B is the treble. There's just this weird signature in it that makes it a little... honky. I prefer the M50's treble.
Mids are noticeably clearer on the HD668B. The M50s sound a little warm, while the HD668B is crisp and sharp. According to my ears, the sound signature of the HD668B is slightly (very slightly) to the warm side, with sharpness existing in the higher frequencies (giving the illusion of harshness). The M50s are much more warm-sounding and has a lush feel to it though. Don't get me wrong; the M50's mids aren't bad per se, but when compared to the HD668B they feel a little... lacking.
Verdict: The HD668B wins on this aspect. Guitar sounds sound much more clear and sharp and is tight and quick. The M50s have smoother mids, but isn't suitable for electric guitars but probably works better on overdrive guitars. Again, people may prefer the slightly warm, smooth mids as compared to the HD668B's tighter and sharper mids.
Bass-wise, the M50s definitely win in extension, but is boomier and has more reverb than the HD668B. The HD668B has slightly less bass than the M50s though, but it's only a slight difference. The bass on the M50s sound smoother than the HD668B, giving more boom and depth to the lower frequencies, though the HD668B's bass is significantly tighter.
Verdict: Not much say to this. The bass on the M50s is more fun and is nicer to listen to, while the HD668B is colder and more neutral-sounding. Still though, my vote goes to the M50s on this aspect, due to the better layering of the bass regions.
The HD668B definitely has a much bigger soundstage. The M50s sound much more forward and the sound is much more focused than the Superlux. However, the HD668B sounds more natural and spacious, while the M50s sound somewhat closed in. Then again, it's a battle between semi-open and closed...
Verdict: Hands down the HD668B. Let's face it, the M50s are still closed cans, and nothing is going to change it. Though, the M50's soundstage is pretty good for something from a closed can.
Instrumental separation-wise, the HD668B does significantly better. The M50s sound a little congested and narrow, while the HD668B sounds spaced and natural. Drums and distortion guitars bleed in too much with each other and the rest of the instruments (other than vocals) on the M50s while the HD668B works very well with bands and orchestral songs.
Verdict: Another point for the HD668B. The M50s may be great all-rounders, but against the Superlux's strong point the winner becomes clear here.
General sound signature
The M50s sound much more fun yet analytical at the same time, a very nice combo as compared to the cold and analytical Superlux HD668B. However, I still feel that the detail retrieval between the two cans are almost equal, with the Superluxes being more forgiving with .mp3 recordings. The bass on the M50s sound smoother than the HD668B and as I said before extends deeper. Unlike ljokerl's impressions however, I'm detecting that both lower and upper mids fall short in comparison against the HD668B, with the latter being clear, sharper and more fun to listen to.
In short: the HD668Bs are more analytical, sharp and clear, while the M50s are much more laid-back, smooth and has slightly neutral sound. The M50s are also have a significantly more full-bodied sound, very well-layered and nuanced.
VS Superlux HD681F
The Superlux HD681F is a variant of the Superlux studio monitoring series. It's more mid + high accented than the HD668B and has significantly less bass.
The HD681F extends further up the spectrum, so much so that some may call it a little too much. Versus the HD668B, the highs are shinier and vocals sound more forward, with acoustics sounding clearer and nuanced.
Verdict: It's more towards preference for this aspect. Personally, I would go for the HD681F for its shiny, well-bodied highs, but that's just me.
Mids-wise, the HD681F is an improvement to the HD668B. They're slightly more forward, perfect now actually if not for the slightly far-reaching highs overpowering the mids a little. In the end, I feel that the battle mids-wise ends in a draw...
Verdict: Again, it's up to your taste. Personally, I prefer the HD681F's portrayal.
Bass-wise, the HD668B extends deeper and has more reverb balance, but the HD681F is tighter and quicker.
Verdict: I think the HD668B has better bass. The HD681F's bass is lacking a little and could do with some reverb to make it less metallic sounding.
Soundstage-wise, the Superlux HD681F is more natural and spacious. Eric Clapton songs and Hotel California live sounds absolutely lucious on the HD681F, with acoustics sounding much more extended and sharp than the HD668B. The HD681F sounds more forward in the middle and higher frequencies, but background ambience and atmosphere sounds VERY wide and very natural. The HD668B sounds more like a semi-open, wide soundstage but with the slight warmth of a closed can, while the HD681F sounds more like a true open can, with only hints of closed can signatures.
Verdict: Frankly, the HD681F sounds better. It's more natural; important sounds are pushed more forward while ambient and background sounds sound spaced away and immerse around you very nicely.
Instrumental separation-wise, the HD681F wins, but only by a slim margin. Instruments sound slightly more individualised in the HD681F than the HD668B, and melds a bit less with the rest each other. Soundstage and detail pickup in the higher frequencies still remain as the selling point of the HD681F.
Verdict: I prefer the HD681F more, but the difference is very minute. I guess this ends in a draw.
General sound signature
In short: overall, the HD668B is much more balanced, but the HD681F sounds more natural if not for the slightly shiny highs. The HD681F is more suited for live music while the HD668B is balanced and fits any kind of music, with the exception of energetic music.
Imagine when AKG and Audio Technica had a b*stard love-child raised by a Beyerdynamic. A very detailed headphone with great soundstaging.
This kind of quality for $50... it's just unbelievable.
Edited by crinacle - 10/8/12 at 8:29am