The original K3003/i (with /or without microphone for i-devices) is a three ways array hybrid, one DD for bass and two BA for mid and highs, not many IEM had this configuration beforehand, many copycats to follow, but K3003/i was the original (and still the best). Before the K3003/i, only single DD has the overall tonal, soundstage, etc which audiophile thrills on, BA/ multi has the size advantage, but overall tonal sounds thin and lack of...