Originally Posted by bahmah
Thanks for the helpful replies. I've noticed myself turning the iPod up to max. recently but I don't think it's my ears getting weaker. I'm convinced I just need better headphones.
More efficient but not too low impedance headphones or IEMs. Some use 16ohm or below impedance to squeeze more power out of the amp or device driving it but often that might actually cause other problems since that can be too low already.
While it's true that we perceive detail differently at different volumes, given that there is no headphone with a perfectly flat response or does a perfect image of the soundstage, then it's possible that a better headphone or IEM might help. There is no decent quality headphone or IEM (or speakers given an acoustically great room) that does not produce certain sounds within its response range. The problem is how much concentration is needed to pick these out of the playback image, since in some cases some notes can be too soft and others can be too loud, enough to obscure some details unless you really focus on hearing certain sounds (which is not how one should listen to enjoy the music).
Also the source and amps can play a part in the response of the headphone/IEM or speakers in the system. In some cases the analog output stage after the DAC can add its own "flavor" to the sound (asuming the DAC chip itself is of decent quality); in other cases, the amp even if it measures flat on a test tone, might run into trouble driving a complex load where the impedance rises or drops too far from the nominal rating on some frequencies, and the amp fails to step up when those notes hit. On mainstream devices you have an integrated DAC+Amp audio chip, so there's no analog output stage to screw it up before the amp itself, but present that amp with a too low nominal load that also swings wildly, and such an amp would more likely run into trouble as it doesn't have its own power supply and capacitor banks.*
So basically you might want to upgrade to a good IEM (so it also has less space between the drivers and your ear drums to screw up detail) as well as a good player. Read up on how to load files on them though, especially since you have an iPod. Anyone on Windows and Linux would tend to like these devices for drag and drop transfers, but some can't even use Browse Mode because tehy don't organize them into folders since iTunes tags them and organizes them anyway, then turns out some other software can't read iTunes tags properly.
*think of this as an integrated GPU and there isn't enough RAM in the computer dedicated to it