The Hifiman RE-400i is the easiest recommendation of all, it's affordable, but offers more than a glimpse of high-end sound. Play a good lossless file over these 'phones, and you'll be totally sold on high-end sound.
The RE-400i's sound is so well-balanced and pure, at first you might not realize how good it is. Its unforced clarity is easy to listen to for hours on end, probably because there's no boosted treble or trickery of any kind, the RE-400i just goes about its business sounding accurate and natural.
No doubt about it, the Beyerdynamic DX 160 iE's makes a lot of bass, but it's not thick or muddy. Definition is excellent, and this headphone's sound clicks with rock, jazz, electronica, and classical music. Midrange detailing is excellent.
This is easily the most transparent sounding in-ear headphone I've heard for this kind of money. It's also super-comfortable, solidly built and comes with possibly the longest headphone warranty extant, it runs a full 5 years (review to come).
These sleek-looking, stainless steel T10i in-ears come with three sets of "tuning filters " that slightly alter its frequency response. In any case, the T10i is clearer sounding than the Bowers & Wilkins' excellent C5 S2 on-ear headphones.
With the Hifiman RE-600 it's all about accuracy and precision, and while you might think those are givens with all audiophile headphones, most have at least some bass bulge or midrange enhancement. Not this one, and their tiny size ensures maximum comfort.
When it comes to getting the sound you paid for with in-ear headphones, achieving a perfect ear tip seal is absolutely crucial. The seal also more effectively blocks external noise, so to that end Ultimate Ears includes the biggest selection of tip types and sizes than any other in-ear we know. The UE900s sound is also beautifully balanced and highly transparent.
These tiny, universal fit in-ears are super-comfy, and the bass-midrange-treble balance is perfect, says the Audiophiliac. This is one of the very best sounding universal-fit in-ears, on par with much more expensive custom molded in-ear designs. There's only one downside, the IE 800 doesn't block external noise as well as the customs.
The custom-molded 1964 Ears V6-Stage is a "three-way" design with six balanced armature drivers (dual bass, dual midrange, and dual treble). Each pair of 1964 Ears V6 Stages are made to order, so custom colors, finishes, and artwork can be used to personalize your headphones. This headphone digs deep into the more subtle elements of a recording, so I heard stuff like the singers' breaths and the instruments' textures.
The Westone ES60 custom molded in-ear is the "quietest" headphone we've heard. Superior noise-blocking makes a huge difference when you're in a plane, bus, train, office, park, or any noisy environment. Unlike noise-canceling headphones that use battery-powered electronics, the ES60 hushes noise by creating a tight seal in your ear canal.
The treble detailing is incredible, so percussion instruments really come alive. Bass is flat-out amazing; when a drummer really hammers his kick drum you feel it. The bass' taut definition, texture, and shading is ahead of the pack. The Westone ES60 is the best sounding in-ear headphone on the planet.
Each ES60 is hand-built in Colorado Springs, Colo.