Here’re the results I got with each headphone:
Jazz/Classical: Nicely balanced, natural-sounding mids and highs. This is about the level of performance I’d expect from a good $25 in-ear headphone. To my surprise, though, the bass sounded unnaturally pumped up and a little “fat” and undefined — not a sound I associate with jazz or classical, more like an old-school R&B/soul kind of bass.
Hip-Hop/Rap: The weirdest-sounding headphone I’d ever heard. It sounds like a speaker run through a 3-inch ABS pipe then muffled through a pillow. Or like the sound of a pumped-up car stereo when the windows are rolled up and you’re outside the car. The midrange is extremely colored, like the singer is using a megaphone. There’s a big emphasis on upper bass, but not much deep bass to speak of. This isn’t a sound I associate with hip-hop (much of which is quite well-recorded).
Pop/Easy Listening: This category I don’t get — like the same headphone is supposed to sound right for Ke$ha and Perry Como? Anyway, this one has some of the midrange coloration of the Hip-Hop/Rap model, but a more even and open sound. The treble seems slightly boosted and a bit overly crisp; cymbals sound like they’re made from steel rather than brass. It does make pop tunes sound a little, well, poppier.
Rock/Blues/Country: This one has a rather thin tonal balance, but plenty of bite in the midrange. It seems like it was voiced to make rock guitar sound more kick-ass. It certainly did the most to bring out the guitars (and even the nearly buried keyboard parts) in “Dancing Days,” but Zep’s inimitable groove was lost.
Some quick measurements with a simple tube coupler (not what you’d call a reference measurement, but adequate for the purpose of comparison) comfirmed much of what I was hearing. The jazz/classical model (blue trace) has by far the flattest response but with a very audible bass boost at 40 Hz. The hip-hop/rap model (red trace) has an upper-bass boost at 100 Hz but not much low bass, and a big notch at 550 Hz. The pop/easy listening model has some treble boost and a notch at 700 Hz. The rock/blues/country model has a less-extreme notch at 550 Hz and a bass boost at 30 Hz, which isn’t as audible as the jazz/classical model’s 40 Hz boost. (The lowest note on a standard electric or upright bass is 41 Hz.)
After auditioning all the InTunes, I can’t buy into the concept of particular voicings for particular kinds of music — in fact, IMHO the jazz/classical InTune sounded better than all the other ones no matter what music I played. But there’s the genesis of a great idea here: How about a line of headphones with slight timbral adjustments? Start with one that’s flat and neutral. Then do one with just a little more oomph at 40 Hz, one with a mildly uptilted treble and one with a bit of midrange boost. And tell us on the packaging exactly what the headphones do, rather than couching it in a genre or making us extrapolate based on which celebrity endorsed the headphone. InTunes goes part of the way there — the response curves are printed on the packaging — but it’s still confusing even for a guy like me who looks at frequency response graphs every day.
Brent Butterworth and Geoff Morrison combine their years of gear testing and knowledge in one überblog of irreverence and techiness.