The HD681 series headphones offer 3 distinctive sound profiles, each with its own character: The HD681 features an exceptionally deep low frequency, the HD681F has a flat extended frequency response, and the HD681B has an excellent balanced character, and powerful bass punch.

As for the sound image presented by these headphones, the HD681 gives you the feeling of actually being on stage with the artists while the HD681F makes you feel as if you sitting on the front row and the HD681B puts you in the middle of the concert hall, enjoying a deep, rich sound. These three headphones also deliver excellent balance and clarity. The ergonomically-designed vinyl ear pieces combined with the lightweight and self-adjusting headband of these headphones make them very comfortable. Whether you’re monitoring, tracking, mixing, or just listening to an MP3 or other audio source, you can expect comfort and sonic accuracy from your HD681 series headphones.

Features

1. Accurate and detailed sound greatly enhances your listening
    experience 
2. High efficiency and wide dynamic range 
3. Durable construction allows it to be twisted for use as a single 
    ear headphone 
4. Self-adjusting headband for great fit and maximum comfort 
5. Single-sided, straight cable 
6. Outstanding quality and value 
7. Environmentally friendly packaging, good for displays and easy to
    store 

Frequency Response

HD681F
Flat extended frequency response “Front row” sound image, great for pop music and capturing that sweet vocal sound.

Both the HD681F & A-brand AD500 have a similar curve. The HD681F delivers a sweet sound, just as if the singer was standing right in front of you.

Type: Dynamic, Semi-open 
Driver: Φ50mm, neodymium 
Sensitivity: 98dB SPL (1mW)
Frequency Response: 10-30,000Hz 
Maximum Power: 300 mW 
Rated Impedance: 32 Ω (copper-coated aluminum wire)
Earpad：leather
Cable: 2.5-meter (8.2 ft.) straight, single-sided 
Connectors: Screw-on gold plated stereo mini plug
Headphone Caliper Pressure: Approx. 3.5N 
Net Weight: 276g(9.75 oz)