Equalizer APO - A system-wide equalizer for Windows 7 / 8 / 8.1 / 10 with channel remapping/copying capabilities
FxSound - Clearer Sound for Your PC. The new FxSound boosts your sound quality, volume, clarity and bass.
Boom 2 - Boom is a simple volume booster that lets you boost the volume of your Mac and your music files.
DeskFX Audio Enhancer Software - Download this free audio utility to refine, control & perfect the sound playing on your computer. Live audio effects include amplify, equalize, reverb, chorus and more. Studio quality sound from your PC or Mac in pure digital.
eqMac 2 - The open-source macOS audio optimizer 🎛️
Bongiovi DPS - Instantaneously correct, improve and optimize the sound of any computer system with Bongiovi DPS.