Etymotic proves that the ER4 line of products is far from retirement with the ER4 XR. It is what a lot of fans of the ER4S have been looking for ever since its release 25 years ago. The nudged-up bass response makes the ER4 XR much more engaging to listen to with contemporary music, and it is arguably the more natural-tuned for a set of in-ears. The treble is as always insanely good. You get all the details exactly the way they were intended, without any compromise in the upper midrange, just as the elevated bass does not color the midrange or mask lower midrange details. The XR is the ER4 for the masses. The slender cylindrical design just works across so many ear shapes and sizes despite being so simple.