Ear Candy - Ear Candy is a sound level manager that nicely fades applications in and out based on their profile...
Synchronous Audio Router - Routes Windows application audio to and from your digital audio workstation software.
EarTrumpet - Volume Control for Windows
Virtual Audio Cable - Ever wanted to record your speaker output? (loopback) This is for you.
Volume2 - Volume2 is an advanced Windows audio mixer, a complete replacement for the standard Volume Control.
Voicemeeter - Audio Processing and Audio Programming by V.Burel