The earphones received were the Shure SCL2 which are the professional version of the E2C (although I ordered the E2C (this is why I can't put 5 stars)).The sound quality is exceptional! The frequency to which it responds is 22Hz to 17.5kHz (respectable). I've listen to different kind of music (including Techno/House, Classical, Blues, Hip Hop and Rock) and the sound is very good.The isolation is also impressive: even with the music to a low level (about 1/6 of the max in my case) I cannot have a normal conversation with the surrounding.The only bad point are the bass which aren't very good. If in your budget, consider buying the SE110 which have better basses.