Output Buses

An output bus is a destination with its own mix. Where input channels answer "what comes in?", buses answer "who hears what?" — and the power of Aura Mixer is that the answers can differ per listener.

You always have the Main L+R bus, plus additional buses — a couple on the Free version, many more with Premium (details).

Main L+R — the master

Main L+R is the default destination: freshly added channels are routed to it automatically, and it's pinned first in the monitor dropdown. Point it at your everyday headphones or speakers (SELECT → SETUP → Output Device) and you have a classic master bus.

It behaves like any other bus — fader, EQ, limiter, delay — it just can't be deleted.

Bus types

Like inputs, buses have a type badge:

• 🎧 PHYS — physical output. Plays to real hardware: headphones, speakers, a second sound card. Use extra PHYS buses for a second listening zone — e.g. speakers for the room on one bus, your headphones on another, each at its own level with its own EQ. A virtual cable's playback device (VB-Audio, Voicemeeter, VAC…) shows up in the same device list — point a PHYS bus at one when an app needs your mix as a microphone input, most commonly Discord voice: the other app then picks up that cable as its "microphone".
• 🎥 APP — application capture. A hidden helper renders the bus so that OBS (or any app with "Application Audio Capture") can grab it directly — no virtual cable needed. In OBS you add an Application Audio Capture source and pick "Aura Mixer — {bus name}". The bus also plays on a device you choose (pick one you don't monitor for a capture that's silent to you). This is the easiest way to hand a clean mix to a streaming or recording app.

Why several mixes?

The classic streamer's problem, solved by two buses:

You hear everything; the stream gets mic + game but no copyrighted music and no private voice chat. The same pattern covers recording (clean feed without notifications) and calls (Discord hears your mic, not your music).

Routing is controlled in the Routing matrix (menu → Routing) — a grid of inputs × outputs where each crossing point is a switch. The SENDS tabs then fine-tune how much of each channel feeds each bus, in dB.

What a bus does to its audio

Everything routed to a bus is summed, then processed as one signal — the bus's own DSP chain:

sum → EQ → LIMITER → FADER → DELAY → device. See How Audio Flows for the full picture.

• EQ — correct this destination: tame boomy speakers, brighten dull headphones. Lives on the bus so it never colours other mixes.
• LIMITER — a ceiling that catches peaks when several loud channels stack up. Especially worthwhile on stream/recording buses, where clipping is forever.
• FADER — the bus's master level, on the strip.
• DELAY — shifts the entire bus by a set time, the standard fix for audio running ahead of video.

Monitoring — listen to any mix

The MONITOR dropdown in the monitor bar lets you put any bus in your ears without changing any routing: select the stream bus and you hear exactly what your viewers hear. The monitor VOL and DIM controls affect only your listening level — never the mix itself.