There are plenty of options available to us when it comes to altering the sound quality of our devices. Some are overkill and will bombard you with options and settings that are generally superfluous as far as a mobile device is concerned, others (in my humble opinion) are single function gimmicks devised with the sole intention of making a product desirable to tweens. Thankfully, somewhere in the middle lies the good old fashioned Graphic Equalizer—a simple, yet effective tool that will allow you to tweak the sound of your device with ease.
XDA Senior Member meltus has developed and app called Volume+, which is a 5 band EQ with added functionality. As well as allowing you to alter the equalization, your custom settings can be saved and restored at will. A selection of commonly used EQ presets are also included to get you started. Volume+ also has the benefit of allowing you to assign various settings for either the speaker, headphones, Bluetooth audio, or in-call sound independently. Combine these functions with the ability to increase the overall volume, and you have a very flexible application for anyone who may not satisfied with the sound of the device. The equalizer requires Android version 2.3 or greater to run.
So if you feel that your sound could do with a little low-end boost or a cut in treble visit the original thread._________