The question becomes, how do we define accurate then... Accuracy deals with how well does it reproduce what it is playing, true? So what happens if the music it's playing wasn't mastered properly, compressed like most are. It won't sound natural by any means because it was mastered unnaturally. Can we call that IEM accurate if it tries to change this (make something that actually is unnatural natural)? An accurate IEM, IMO, will reproduce what it's being fed. If it's fed garbage, you'll get garbage out. If it's fed quality, it'll reproduce quality. If it's fed something that is mastered properly (and will sound natural), it'll sound natural. With the W4R BTW, I did find the treble a little edgy and slightly sibilant at times due to the spike at the 10 kHz. It's a very natural IEM, I don't consider it neutral or accurate (to what it's playing). On the other hand, it does help many poorly mastered tracks tremendously and make them sound a lot more natural, less fatiguing, more musical.