Red: RAW Black: Olive Welti Target Blue: Diffuse Field Target Distortion 0.2% THD @94db (500hz) So this DIRAC seems to be the very first IEM incorporating this new SF - Super Fidelity DD from Sonicast. This dynamic driver supposedly has near perfect control over surface split vibration. This enables driver to reproduce very high frequency over 10khz with low distortion. test setup Driver Assembly: This IEM is not released yet and currently in pre-order stage. I believe they will be available later this month in Korea. Currently, I could not find any place that ships this to Canada, so I asked my friend in Korea to forward me few sets. So yeah.. I haven't heard it yet, but few credible source (reviewers at seeko and beta testers) told me they sound pretty amazing for any price, but at suggested retail price of US$42, staggeringly good. Just looking at frequency response, I wish they will release something with slightly tamed bass by around 4-5dbs in near future.