If you have ever tried to use the same set of headphones, whether wired or wireless, in a number of smartphones, you must have seen that they produce different quality of sound on different devices. The problem is not usually in the headphones (if you have bought some standard quality headphones like from Beats or Sennheiser or Philips), instead the problem is usually in the way a device is reproducing the sound from the music files into the audio signal that goes into the headphones. A smartphone with built in amplifier will produce much better sound than the one without an amplifier.
You can always improve the sound quality of your Android smartphone using sound quality enhancer app like Equalizer FX. This app is not only an equalizer, but it can also boost the bass, enhance the loudness of sound and virtualize the audio channels even though your phone has only stereo sound. The app opens up with a standard equalizer screen where you can use the sliders to increase or decrease the filters for a particular set of frequencies. This way you can create your own custom filter.
But you are not limited to using a custom frequency filter set by you. You can actually switch the the “Profiles” section and pick any of the pre-configured profiles like Super Bass, Dance, Lite, Heavy Metal, Pop, Blues, Rock and many more. You can also choose some of the settings to boost the bass, enable virtualization for the audio channels, and if you are feeling the sound is not so loud then you can also increase the sound loudness using this app.
In the settings for this app, you can choose if you want to view the notification icon for the Equalizer FX or if you want it to keep running in the background. The icon can also be made a low priority icon making it visible only if you pull down the notification panel. There is also an option to integrate Equalizer FX globally with all the apps so you can have the effects applied to matter which app you use to listen to the music. This option is useful if some app is not accepting the sound effects.
You can download Equalizer FX app from https://play.google.com/store/apps/details?id=com.devdnua.equalizer.free.