Equalizer APO

Parametric / graphic equalizer for Windows that lets you build a virtual audio chain of devices.

Website:

Equalizer APO

More info:

EqualizerAPO + ReaPlugs VSTs (Mic processing without virtual cables)

MIDI Mixer

MIDI Mixer is a piece of Windows software that enables you to connect to and control your Windows audio.

Website and more info:

MIDI Mixer - Control Windows volumes (and more) with MIDI