If your iOS device is connected to the same Wi-Fi network as your AMP, you can adjust the Equalizer using the Airhome app.
First, open up the app and allow the Rooms List to populate. Swipe left on your AMP in the list to reveal the Settings, EQ, and Mute menu. Tap the Equalizer icon. Here you can manually change the Equalizer settings or select one of the already programmed presets.