Sennheiser's HD 650 headphones have been the audio company's flagship product for around 14 years, boasting top-of-the-line sound system at a reasonable price. People who enjoy listening to music will be delighted as Sennheiser officially announced the successor of HD 650, the HD 660 S, packed with features that will improve the users' listening experience.

As reported by The Verge, the Sennheiser HD 660 S and HD 650 almost look identical based on the exterior. However, the improvements highlighted by HD 660 S are more than just the physical appearance. For one, Sennheiser has developed a new technology for their latest headphones, which will fix the sound distortion. Thanks to a brand new transducer, the HD 660 S will have lower harmonic distortion with more natural and washed-out audio.

Another feature of Sennheiser HD 660 S is the carefully-tested identical sound in the left and right ear cup of the headphones. The tolerance between the left and right earpiece is just around +/- 1dB. The HD 660 S has its impedance lowered to 150 Ohms, which will make the sound more powerful even without using an extra headphone amplifier.

Sennheiser has been focused on delivering high-quality sound performance with the HD 660 S, although the company has also taken the comfort of users into consideration. The HD 660 S is designed to feel light and easy on the ears even for prolonged listening sessions. The earcups and headband of the headphones have gentle padding, plus the earcups are made to be elliptical in shape to fit nicely to the shape of the ears.

Sennheiser HD 660 S will be shipped along with a detachable and oxygen-free copper wire. The wired connection has a gold-plated plug at the end, which measures around a quarter inch, according to Digital Trends. There will be another cord provided for DAC connections, including a 4.4mm stereo plug and an adapter piece ranging from quarter inch to 3.5mm in length.

In spite of its top-quality sound features, the Sennheiser HD 660 S targets the mid-range market with an average price tag. The headphones will be available in the U.S. markets in mid-October for $500.