Speaking of iPhone earphones, "EarPods". Since iPhone 7 with the abolished earphone jack, it was a style to listen to music using "Lightning-3.5mm headphone jack adapter" or "EarPods with Lightning Connector" that connects directly to the Lightning terminal. It's finally no longer included with the iPhone 12, but if you've had the experience of changing models, you probably have stock at home.
EarPods, iOS 14's new feature "Headphone Adjustment" makes it possible to customize the sound quality. Until then, you had to use the equalizer function ("Settings"-> "Music"-> "Equalizer") of the music app, or use the sound quality adjustment function included in the third-party app, but now you can use the music. Sound quality can be adjusted regardless of the playback application.
Setting is easy, after connecting EarPods to iPhone, open the screen in the order of "Settings" → "Accessibility" → "Audio / Visual" → "Headphone adjustment", and turn on the "Headphone adjustment" switch. By default, the "voice range" that emphasizes the midrange is checked, but if you want to emphasize a wide range, select "balanced tone", and if you want to focus on the high range, select "brightness". Check it. When a compatible earphone is connected, "Play sample" can be tapped, and you can make adjustments while listening to the song.
By tapping "Custom Audio Settings", you can customize the sound quality to your liking by answering the questions. You will be asked repeatedly, "Which sound do you prefer?", So you can answer as you feel. The impression of the sound of EarPods should change a lot.
In addition to EarPods, this "headphone adjustment" can also be used with Apple / Beats products such as AirPods Max, AirPods (2nd generation or later), and Powerbeats. If you have an unsupported earphone connected, you will see "Headphones not supported" when you tap "Custom Audio Settings".