My iPhone 5 is much quieter than previous iPhones, and that’s a problem: a lot of the music I listen to is quiet, or unmixed and uncompressed, and that means it isn’t loud enough when I’m on the bus. If you’re suffering from the same problem, there is an easy and free way to solve it.
Step one: download Denon Audio from the App Store and use it instead of the default Music app.
Step two: in the EQ view (shown here), click on the settings icon in the top right hand corner.
Step three: choose the Flat EQ option.
Step four: you should now see a single straight line with two points, one on either side. Drag one of them upwards, then drag the other one up to the same point.That boosts the volume of everything without changing the sound, although of course you can create a custom EQ if you want to do that. If the limiter option is on (it’s in the Settings screen, and enabled by default) then even if you turn it up too loud you won’t get horrible clipping distortion.
Step five: there is no step five. Hurrah!
[You can only do so much with EQ. If the app doesn’t improve things enough, you might want to do what I did and buy a little headphone amp.]