Superlux HD 681 Headphones Review

The Superlux HD 681 look very similar to the HD 668B. They have practically the same ear cups but a different headband design. This makes the HD 681 look even more like the AKG K240 MKII. The color scheme is pretty bland but this model stands out a bit more compared to the HD668 thanks to the red accents on the ear cups and headband. Unfortunately, their plasticky build quality makes them look cheap and not durable.

The Superlux HD 681 are more comfortable than the HD 668. They're just as lightweight and have a better headband design that doesn't feel as tight on the head and extends a bit further than that of the HD 668. They also have large ear cups that fit well around most listeners' ears. Unfortunately, the padding on the ear cup feels a bit stiff and may cause a bit of uneven pressure. It's not particularly uncomfortable but it is noticeable after wearing them for a while.

The Superlux HD 681 are lightweight but bulky and cumbersome headphones. The ear cups do not fold or lay flat, making them difficult to carry around on your person if you do not have a bag.

Comes with a somewhat, rugged pouch that will shield the headphones from scratches and minor water exposure. However, it will not protect your headphones against drops and impacts.

The Superlux HD 681 like the HD 668B are cheaply made and plasticky. They feel like a budget version of the AKG K240, which shows in their build quality. They have a plastic design with no metal parts, and all the materials used in their build quality feel slightly low grade. They won't break if they accidentally fall once or twice, but they don't feel like durable headphones.

The HD681 are not as tight on the head as the Superlux HD 668B and are slightly less stable overall. They won't be the best for sports since they have big ear cups that sway during physical activity but they don't move much during casual listening sessions. Unfortunately, this model does not have a detachable cable so the headphones will get yanked off your head if the cable gets hooked by something.

• Superlux HD681 Headphones
• 1/8" to 1/4" Adapter
• Carrying pouch
• Manual

Good Consistency performance. The Bass Range performance is very consistent across our human subjects, except for our subject who wears glasses as he gets 3dB less Bass than others at 20Hz. The Treble Range consistency is also very good, especially below 10KHz.

Excellent Bass Range performance. Low-frequency extension is at 14Hz, which is great. The entire Bass response is virtually flat and within 1dB of our target.

Very good Mid Range performance. Low-mid and Mid are virtually flat, but under our target by about 2dB. This pushes vocals/leads slightly to the back of the mix and giving more emphasis to Bass and Treble Ranges. High-mid shows a small tilt favoring higher frequencies, but the effect will be very subtle.

Decent Treble Range performance. Low-treble is well-balanced but slightly inconsistent. Treble has a 10dB bump between 7KHz and 12KHz which makes the sound of these headphones noticeably sharp and sibilant.

Poor Isolation performance. Due to the semi-open back of the HD 681, they don't isolate at all in the Bass and Mid Ranges. In the Treble Range they reduce the outside noise by about 20dB, which is decent.

Poor Leakage performance. The significant portion of Leakage on these semi-open back headphones sits between 500Hz and 20KHz which is a broad range. Additionally, their overall level of Leakage is also relatively loud.

No compatible app.

Wired connection negligible latency (see our recommendations for the best wired headphones).