Turns out, replacing the eartips and filters on your Etymotic 6i headphones can result in a nontrivial increase in fidelity, especially if you use them a lot, and have had them for over four years and use them fairly frequently. So, you know, do that.

BTW, if you fly a lot — or, really, at all — you can’t beat these Etys (unless you go upmarket, and buy nicer Etys; the 6i set is designed for use with mp3 decks, and therefore don’t require an extra amp). The “in-ear” monitor style of headphone produces more sonic isolation than any of the big, bulky active noise-reduction phones from Sony or Bose, and are much easier to carry. They’re not cheap, but few genuinely high-quality things are. (Plus, about an hour into a long flight with a chatty seatmate, the the prospect of $150 headphones will seem like a bargain. Trust me. I know things.)