HD660S has a simple, practical design. At a glance, it is quite similar to the HD600/650 series, but there are still small differences to distinguish it from its senior products. The most visible is the mesh on the back, the paint shell and the driver texture.
The coating on the headband has also been reworked by Sennheiser more carefully to prevent peeling after a period of use or for people who sweat a lot, solving the annoying problem of appearance that was once on the HD600/650.
Gentle wearing feeling, comes with an elliptical earcup design that covers the ear with just enough pressure. The earpad of the headset is quite thick, enhances sound tightness, worn in an air-conditioned room, it does not feel uncomfortable, hot or clogged. HD660S has a weight of only 290g, which is light.
HD 660 S has a crispy bass, more tension and speed, the midrange is still sweet, soft, but clear and delicate, accompanied by treble if compared to the previous 2 seniors, it has more energy, High fidelity, spacious sound field, comfortable.
The HD660 S has a pretty good overall sound quality and is at a reference level for headphones ranging from 20 million or so, the overall sound is quite flexible and flexible, making it attractive to even experienced audiophiles.