How Does an Audio Mixer Work?
Updated Nov 13, 2026 · By 
Jonah Mercer · Editorial policy
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An audio mixer takes in sound from several inputs at once, adjusts the level and tone of each one, and blends them into a single output. Each input has its own channel with gain, EQ and a fader, and the main mix sends the blend onward. The Behringer XENYX X2442USB shows the layout: 24 inputs, mic preamps and British EQ.
Inputs and channels
Each sound source plugs into its own input, and each input has a channel on the mixer. The Behringer XENYX X2442USB has 24 inputs, so 24 sources can feed it at once. A channel carries a mic preamp, which raises a microphone signal to a level the mixer can work with. The mixer is a 4/2-bus design, so channels route to 4 subgroups and a stereo main mix.
Gain, EQ and compressors
Gain sets how strong each input signal is before it reaches the rest of the channel. British EQ shapes the tone of an input, and the compressors even out loud and quiet parts of a signal. The Klark Teknik FX processor adds effects to the mix, and the USB interface sends the mix to a computer for recording.
Faders and the main mix
Each channel has a fader that sets how loud that input sits in the mix. Raise a fader to bring a source forward, and lower it to push that source back. The main mix blends all the channels into one stereo output, which goes to speakers or a recorder. The Behringer also connects over USB Type B, so the mix can reach a computer.
The mixing boards are different tools
Three of the products here are mixing boards for automotive body filler, not audio mixers. The Custom Shop board is reusable plastic with 4, 5 and 6 inch spreaders, the Custom Shop paper board holds 100 disposable sheets, and the KREFINISH board holds 100 sheets with a 5 inch spatula. They mix filler, putty, glaze and epoxy for auto body work, so they do not mix audio.
What you need
Behringer XENYX X2442USB Premium 24-Input 4/2-Bus Mixer
A 24-input mixer with XENYX mic preamps, compressors, British EQ and a 24-bit multi-FX processor, plus a USB audio interface.
- Mixer channels / decks: 24
- Built-in effects / amp models
Custom Shop Body Filler Mixing Board
A reusable plastic body filler mixing board with 4, 5 and 6 inch spreaders and a scoop, for automotive filler and epoxy, not audio.
Custom Shop Multi-Layered Disposable Paper Body Filler
A multi-layered paper mixing board with 100 disposable sheets, 10 by 11-1/2 inches, for body filler and glaze, not audio.
KREFINISH Body Filler Mixing Board Disposable Paper
A disposable paper mixing board with 100 sheets and a 5 inch plastic spatula, for body filler and epoxy, not audio.
These come from our ranked list Best Mixing Board, which compares them spec by spec.
Frequently asked questions
What does each channel on a mixer do?
Each channel takes one input and gives it gain, EQ and a fader. The Behringer has 24 inputs, so 24 sources can feed it at once, and its mic preamps raise microphone signals to working level.
Do I need the mixing boards for audio work?
No. The three mixing boards here are for automotive body filler, putty, glaze and epoxy, not for audio. Only the Behringer XENYX X2442USB in this set is an audio mixer.
What is the USB connection on the mixer for?
It is an audio interface, so the mixer can send audio to a computer over USB. The Behringer connects over USB Type B.
Ranked audio mixers lists
More how-to guides
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