This is the basic idea, but there are other apps which can make it easier. I prefer using Audio Hijack for the EQ part and sending it to a pass-through device set up in Loopback (which, for this use case, functions the same as BlackHole). Source: 8 months ago

- Audio Hijack (also by Rogue Ameba) so I can record myself, the soundboard, and QuickTime all to individual .aiff files. Source: 11 months ago

Another option that has been around for a long time. https://rogueamoeba.com/audiohijack/. Source: 12 months ago

Definitely doable though might point to Rogue Amoeba re: implementation/execution particularly: SoundSource, Loopback & Audio Hijack. Source: about 1 year ago

If you want to record application-specific audio (like from a game but not from Spotify) then it’s more complicated. Audio Hijack is a good app for this: https://rogueamoeba.com/audiohijack/. Source: about 1 year ago

Not sure it has those specific features but you may want to check out Sound Control. Source: 11 months ago

SoundControl is exactly this and more: https://staticz.com/soundcontrol/. Source: about 1 year ago

Hey, bro, I think I've found a solution: I installed the SoundControl software, enabled the "Force Soft Volume Control" option. Yay, the volume is now adjustable! Hope this helps you too! Screenshot. Source: about 1 year ago

I haven’t installed it yet, I’ve got a few days off and don’t want to waste the trial period. This is the one I bookmarked from the ones I found: https://staticz.com/soundcontrol/. Source: about 1 year ago

IDK whether a 3rd party software audio mixer would help; you may download a trial here: https://staticz.com/soundcontrol/. Source: over 1 year ago