If you want closed-back headphones with passive noise reduction and a simple one-sided cable for workout listening, choose Superlux HD-662; if you need detachable cables in two lengths for a more adaptable wired setup, choose Superlux HD-681. For workout use, neither is a wireless or purpose-built sport model, so the choice comes down to how their wired designs fit your routine.
• Superlux HD-662: Closed-back, over-ear design with passive noise reduction, a 50 mm dynamic driver, and a one-sided cable. Its trade-off is that the cable is not listed as detachable.
• Superlux HD-681: Over-ear design with a detachable cable and two included cable lengths, 1 m and 3 m. Its trade-off is that the listed noise control is “None,” rather than passive noise reduction.
• Both are wired, use 32-ohm impedance, and have a stated frequency range of 10 Hz to 30 kHz.
• Choose the HD-662 if a closed-back design and straightforward single-cable connection matter most.
• Choose the HD-681 if being able to remove the cable and choose between two lengths matters more.
The HD-662 is a closed-back, over-ear pair built around 50 mm dynamic drivers. Its stated frequency range is 10 Hz to 30 kHz, and the product information describes its sound as accurate and detailed, with natural deep bass. Those specifications and design choices point toward a pair intended for monitoring as well as ordinary music listening, rather than a feature-heavy wireless headset.
For workouts, the closed-back construction and listed passive noise reduction are relevant distinctions. They may make the HD-662 a more sensible pick than the HD-681 if you want less outside sound reaching you while listening. That is not active noise cancellation: the product is wired, and the sheet does not list a microphone, Bluetooth, a battery, or workout-specific controls. The one-sided cable keeps the connection on one side, but the supplied information does not state its length or that it can be detached.
Superlux describes the HD-662 as having a lightweight design, self-adjusting headband, and comfortable, durable earmuffs intended for longer listening sessions. Its listed weight is 0.35 kg, so comfort claims should not be confused with a particularly lightweight figure. It also has a 3.5 mm jack and 32-ohm impedance. Those details make it a straightforward wired option for compatible audio sources, while leaving the wearer tethered to the source during movement.
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Skip it if you need a detachable cable, wireless freedom, or a headset explicitly designed for exercise.
The HD-681 is also an over-ear wired headphone with 50 mm dynamic drivers, 32-ohm impedance, and a frequency range of 10 Hz to 30 kHz. Its listed sensitivity is 98 dB SPL per 1 mW, and its maximum input is 300 mW. Those are useful reference points for understanding the headphone’s stated electrical specifications, but they do not establish a particular listening experience on every device.
Its clearest practical advantage is the detachable straight cable. The package information lists two cable lengths, 1 m and 3 m, each with a 3.5 mm gold-plated stereo mini plug. A shorter cable may be more convenient when the audio source is close; the longer one offers more reach when listening at a desk or another stationary spot. Being able to unplug the cable also gives the user a way to remove it for storage or replacement, although no replacement cable is specified as included beyond the two listed accessories.
The HD-681 is identified as a white, over-ear model, with plastic listed as the enclosure material and a listed weight of 265 g. Its noise control is listed as none. That makes it a less obvious choice for someone prioritizing passive isolation during a workout or in a noisy environment. The detachable connection and cable options can still appeal to someone who wants a wired headphone that is easier to adapt to different listening setups.
Skip it if passive noise reduction is a priority, or if you want a wireless or explicitly workout-focused headphone.
• Best for a closed-back design → Superlux HD-662. It is explicitly described as closed-back, while the HD-681’s listed noise control is none.
• Best for passive noise reduction → Superlux HD-662. Passive noise reduction is listed for this model; neither sheet describes active noise cancellation.
• Best for choosing cable length → Superlux HD-681. It comes with detachable 1 m and 3 m straight cables.
• Best for removing the cable from the headphones → Superlux HD-681. Its cable is described as detachable; the HD-662’s is described as one-sided, with no detachable feature listed.
• Best for a simple one-sided connection → Superlux HD-662. That cable arrangement is part of its listed design.
• Best if weight is a deciding specification → Superlux HD-681. Its listed weight is 265 g, compared with 0.35 kg for the HD-662. The figures are presented in different units, so consider them as listed rather than treating them as a controlled comfort comparison.
• Best for workout listening when you want a closed-back option → Superlux HD-662. Its design is the closer match, but it remains a wired over-ear headphone rather than a sport-specific model.
• Best for a wired desk setup with more cable flexibility → Superlux HD-681. The two included lengths give you a choice based on the distance between your headphones and audio source.
Neither model should be mistaken for the wireless gear people often mean when they search for neckband headphones for workout use. Both are wired and over-ear, and neither data sheet lists a neckband, wireless connection, or battery. For exercise, that means the cord and over-ear fit are worth considering alongside sound-related specifications. The available information does not establish whether either design will stay secure during a particular kind of movement.
The same distinction matters for shoppers searching for active noise cancelling sleep headphones for workout. The HD-662 lists passive noise reduction, not active noise cancellation, and the HD-681 lists no noise control. Neither is described as a sleep headphone. If active cancellation, a sleep-focused shape, or wireless operation is essential, these product details do not support choosing either model for those features.
Likewise, a search for a rechargeable gaming headset for workout implies features that are not listed here. Neither sheet specifies a rechargeable battery, gaming microphone, or wireless gaming connection. Both models have a 3.5 mm wired connection, so they may be considered only where a compatible source and a headphone-only listening setup meet your needs.
For everyday use, think about the cord first. If you will move around while listening, a cable can be a practical constraint regardless of which model you select. The HD-681 offers two detachable lengths, while the HD-662 has a one-sided cable and a closed-back construction. If your listening is mostly stationary, the HD-681’s cable choices may be useful; if the closed-back format is more important, the HD-662 has the clearer design advantage.
In my opinion, I would choose the Superlux HD-662 for workout listening if I had to pick between these two: its closed-back design and listed passive noise reduction make it the more relevant match. I would still keep the wired, over-ear format in mind before exercising with it. For desk listening, I would favor the HD-681 when its detachable cables and two lengths are the deciding convenience.
The HD-662 is the closer fit on paper because it has a closed-back design and lists passive noise reduction. Both are wired over-ear headphones, and neither is described as a workout-specific or wireless model.
No active noise cancellation is listed for either model. The HD-662 specifies passive noise reduction; the HD-681 lists no noise control.
The HD-681 has a detachable straight cable and includes 1 m and 3 m cable options. The HD-662 is listed with a one-sided cable, but detachability is not specified.
The HD-681 is listed at 265 g, while the HD-662 is listed at 0.35 kg. Those are the product-sheet figures; they do not by themselves establish which one will feel more comfortable on a particular person.
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