Sennheiser IE 600: Hi-Fi earplugs for a wider audience

Sennheiser previously launched the IE 300 and IE 900, for 249 and 1,299 euros respectively. In between is an alternative: the 699 euro IE 600. This model should bring hi-fi options to a wider audience, but will that come at the expense of the audio experience? Read it in this Sennheiser IE 600 review.