Thinking of buying new headphones for listening to music on your iPhone or iPod touch? You might want to try the Dirac HD Player or the Lite version instead to see if it can improve the sound from the headphones that came with your iOS music player.
Dirac is a Swedish company that does all kinds of high-end electronic equalization for the auto and electronics industry. You can hear their work in BMW, Rolls-Royce or Bentley autos, not that I get into too many Bentleys or other high-end cars...
Dirac has applied its sonic expertise to fixing some of the audio issues with Apple's headsets. The app is not designed for any other headset, as the EQ is quite specific to Apple's original iPhone and iPod touch headphones or EarPods.
The Lite version is free, and doesn't allow you to create or modify playlists, but the audio quality for the free and paid version (US$2.99) is the same.
I gave the app a listen on a variety of rock, jazz and classical tunes I had on my iPhone, and overall I would say the sound improved. My tests were with the Apple EarPods that came with my iPhone 5. The midrange seemed to be boosted, the edge was taken off strings and there was a bit more distinctness to the bass lines. Sometimes I felt the sound was different, not necessarily better, but in most cases I liked the improvement. There are no adjustments to make, other than to decide if you are listening on Apple headphones or EarPods.
A couple of caveats. You can only listen to music from your iTunes library. It won't work on other audio sources, like streaming radio. iTunes Match and iTunes in the Cloud aren't supported yet either, but they are coming.
If you are interested, I would suggest trying the free version to see if you like the sound improvement. If so, you might want to spring for the paid version for the extra flexibility.
I've listened to some other audio enhancers like the SRS iWow app and hardware solution. The results are more dramatic than the Dirac app, but the SRS app requires a hardware clip-on. However, it does work with any headphones and has many more adjustments.
The Dirac HD Players are optimized for the iPhone 5, and require iOS 5.1 or better.