Making an in-ear monitor for personal listening pleasure is quite different to making a in-ear monitor for a musician to use.

Unlike a musician on stage who will only want to hear certain elements (a drummer will want a different set up to a singer for example) a music lover wants to enjoy what the artist created in all its glory, highs, lows and mids in their entirety.

IMR does not create flat frequency response in-ear monitors because apart from the fact it sounds horrible and boring its is NEVER how it was recorded. Bass is meant to be dynamic, rich and present when the track presents it while constantly bringing the midrange to the front and presenting treble in a precise and non fatiguing manner.