Echobox Finder X1 (all three filters)

red line = red filters
dark grey line = black filters
light blue line = white filters

Mentally adding level around 3 and 6 kHz to compensate for my rig's calibration inaccuracy, the treble emphasis is very evenly climbing. Sure, the Finder X1 is no in-ear for treble-shy people at all, but it is a hell of fun to listen to and that's what it was designed for - an in-ear with a fun signature but excellent control, high bass speed and a good detail retrieval.