Audio-Technica ATH-E40 Professional In-Ear Monitor HeadphonesThe ATH E40 professional in ear monitor headphones feature a proprietary dual phase push pull driver design that delivers enhanced fidelity and efficiency. These headphones pack a powerful bass response as well as balanced mid and high frequencies which convey the music's full emotion, from the stage to the street. They also offer specially designed housings that present remarkable isolation. That isolation plus the comfort are both enhanced by the 4