The Koss replace in-ear Sennheiser. Listening mainly classical, I expected too heavy bass, a broad spectrum too pulled down. This is not the case at all. It lacks even a little heat compared to Sennheiser. However, the stereo scene is perfectly defined, with amazing spatiallisation. The headphones isolate outside noise pretty well, but it depends on the shape of the ear canals of each. the rigid conduit inside the headphones can be tricky to position in the ear. Anyway, the point of view sound reproduction quality Koss is the rendezvous. However, the impression of fragility is obvious, the diameter of cables ridiculous raising fears premature tear if they become entangled in a pocket. Handle with extreme care, which is still a problem for an essentially nomadic product.