How Does a USB Mixer Work?


If you are used to recording with analog mixers, the onset of products like the USB Mixers might seem a little baffling. If you know that an audio interface converts analog signals into digital ones, then what does that mean for a mixer with a USB (when mixers are typically analog?)

So how does a USB Mixer Work? A USB Mixer works similarly to an ADA audio interface, in that it converts the analog mixing process into digital to be read by a computer and its recording software.  However, unlike your standard audio interface, the USB mixer still allows you the capability of mixing channels during the process of live performance or live recording (instead of doing the mixing in post on a DAW system.)

It sounds so much more complicated than it actually is. A USB Mixer now provides you the opportunity to mix a recording or live performance without the need of an audio interface, because the USB mixer can now be plugged directly into the computer without the middleman of an audio interface. Below I go into more detail about how USB mixers and audio interfaces differ, what components come with a USB mixer, and reasons why you might record with a USB mixer as opposed to an audio interface.


What is a USB Mixer?


The abbreviation USB stands for Universal Serial Bus. A USB MIXER is a box (similar to that of an audio interface) that has one or more USB ports that allow you to play and record audio directly into your computer. The mixer is capable of, you guessed it, mixing multiple audio sources together, balancing them out, even adding some different effects, to create your ideal sounding audio track. This audio track is then sent back as a single stereo (not mono) output.

Most standard industry mixers do not actually have a way of connecting directly to a computer through USB. In fact, a majority remain analog as opposed to digital (meaning a lot of sound mixers don’t even convert their output in a way that can be understand by a computer). Therefore, older mixers have to be plugged in to an aggregate (like an audio interface) to then be able to talk to a computer while recording.

However, a USB mixer is singular from this older concept of mixers and has slowly become a lot more commonplace inside both home and professional studios. Because the USB mixer sends the recorded audio to the computer as a stereo output, that means that all of the mixing and adjusting you might want done on the track must be done live, during recording (not after), as the individual tracks cannot be mixed once they are on the computer.

A caveat to this is that now some USB mixers do allow the function of creating individual audio tracks from your recording, making each ‘channel’ more like a separate individual (editable) channel (which is more like what an audio interface does) as opposed to the traditional way of mixing and adjusting channels during recording and then when outputted, turning into one single, already pre-mixed track.


What are the Components of a USB Audio Mixer?


As you start hunting for the right USB Mixer, you’ll hear some similar terms on their product description and packaging. Things like ‘channels,’ ‘i/o,’ and buses. In the event you are like, “HUH WHAT?” I’ve made a breakdown of what these components are and what they do, so you’ll feel more confident when looking for your mixer.




This is another way of saying “signal path.” A single channel records one instrument or microphone. A mixer has multiple channels because a mixer is meant to, yes, mix those channels together to create one (pre-mixed) audio track. A mixer that has a lot of channels enables you to connect more instruments and items to the mixer to be mixed. Channels are designed to accept both microphones and line-in devices like amps, preamps, and signal processors.

Channel Strip


The channel strip will be a row of channel circuits that all function together to affect the audio that is passing through the mixer. The channel strip can include up to the following:

  • Input Jacks – this is where external instruments like microphones and guitar lines connect to the mixer (through either an XLR chord or a quarter inch guitar line jack.)
  • Microphone Preamp – this prepares (what is often a somewhat weak mic signal) for processing by raising the strength of the signal
  • EQ – this is the equalization port which adjusts the signal frequency and how it responds
  • Dynamics Processing – this includes compression or gating
  • Fader – this slides along a track in order to control the input or the output of a channel
  • Meter – this is the visual display of the output of each individual channel




This abbreviation stands for input and output. USB Mixers come with differing amounts of inputs and outputs, all of which depends on how many instrument lines you plan to use at the same time. The calculation of I/O for your in home studio mixer should include other devices that will be part of the recording process. That would include such things as processors, mic preamps, headphone jacks, monitor speakers, and instrument lines that direct connect to the mixer




Buses are best described as circuit intersections which allow the output from multiple channels to meet. Each individual channel on a mixer is routed to a specific bus or group of buses. The master mix bus, which is fed by the faders, sends the output of the mixer to the microphone or speakers. Aux buses (or auxiliary buses) are fed by the volume controls of the channels that they are connected to, and they send their signals through their own output jacks (which are called post-faders). These outputs help send a mix of signals to the headphones, processors, or speakers.




A USB mixer with multiple channels will have a grouping function that lets you control and alter multiple channels at once. A group works similarly to a sub-mixer, in that it shares the same signal route, helping to more easily control the master bus. An example of this is if you plugged in multiple drum lines or drum kits, and you want all of those lines (or channels) assigned to one specific group so that you can more easily control the overall drum tone and volume. Likewise, a USB mixer lets you mute a specific group if needed to. (You might want to access the mute group function if you were performing live, for example, and wanted to mute something while speaking.)




An insert lets you connect external sounds from compressors or equalizers into specific channels. On larger mixers there might be something called a patch bay which connects these multiple external devices.


Direct Output


A direct output feeds the USB mixer’s preamp output to the external interface and recording software.


Cue System


A Cue Systems allows you to listen in on specific channels without altering the mixer’s output. The signal is fed through the headphones, and the cue system lets you hear the signal either before or after the fader has made its alterations. Pre-fader listening enables one to listen to the original, unaltered signal, while the after-fader listening lets you isolate the altered (via the fader) signal.  Some larger mixers may also have a solo in place function that mutes every channel other than the one that you want to listen to, which can be especially useful for performing things like sound checks.


What is the Difference Between a USB Mixer and an Audio Interface?


An audio interface connects to your computer via USB (some come with a firewire, which is what I’d recommend using if you have the option). The audio interfaces converts what would otherwise be just an analog audio single from your microphone or guitar, (or whatever instrument) into a digital signal.

Turning something digital essentially means translating the analog function into a set of 1s and 0s (because that is a computers coding, or language, and how the computer can then process analog info on its software.) An audio interface also processes digital signals from the computer back into analog so that you can hear what you just recorded through your headphones via playback (or even hear yourself while you record live.)

When you purchase an audio interface, it will most likely state on the box or its product description that it is ADA. ADA refers to the above process (analog to digital to analog.) Your audio interface will also come with two or more input ports which you plug XLR chords into (like the ones used for professional recording microphones), they also have quarter inch instrument jacks (for guitars) and often have a MIDI instrument plug in option. The amount of inputs varies from audio interface to audio interface, as does the price tag.



Now as you now know, a lot of traditional mixers are analog, and thus actually require being plugged into audio interface to communicate with the computer and the recording software being used. However, now that mixers have become digital and are USB, it does make discerning how a USB mixer and an audio interface is any different. They both are, at that point, different types of audio interfaces that assist in audio digital recording.

The difference then between the USB mixer and audio interface is that mixers are typically used to edit sound live, in the moment, whereas a digital audio interface simply interfaces with the computer (meaning it records and takes that information to the computer – it does not edit or mix anything live. It is simply an aggregate from the live performance to the computer so that it is recording into the computer software.)

Mixers are also used during live performance (not just recording sessions) as they can edit and mix sound in real time.

In general, however, USB mixers and audio interfaces do now have a lot of overlapping functions – and you can technically live record audio with both entities. However, since an audio interface’s one and only job is to record, they (typically) do so very well (as they come with pre-amps inside), and the sound quality is great. USB mixers have a different purpose than a normal audio interface, and do not have high-quality pre-amps inside; thus, sometimes the sound and recording quality may not appear quite up to par with the audio interface.

As the USB mixer becomes more and more common in the marketplace, I am sure they will fix this problem and make the sound quality from a mixer more competitive to be able to match that of a normal audio interface. However, as it stands presently, if you are looking for an easy-to-use, high quality sound recording interface, a standard ADA audio interface is the way to go (over a USB mixer.)

There is also a matter of space inside your home recording studio. An audio interface is typically small, no larger than say, a small laptop computer (and usually more slender than that.) A mixer (depending on how large of one you get) can take up a lot of room.


How Do I Know When to Use a USB Mixer VS an Audio Interface?


If you are in the recording studio with a full band, and you want the sound captured all at once, meaning multiple inputs are recorded at the same time to create one single track, then you would definitely require the use of a mixer or USB mixer. Similarly, when recording drums, each drum has its own input. If you want to capture the sound from multiple inputs (even if just from one instrument) at the same time, you would again need a mixer to create the one drum track (that features all elements of the drum.)

Conversely, if you are at home recording only one instrument line at a time, and you don’t care about mixing live, but would rather editing and mix in post (in the software), then you would not require a mixer, but rather a simple ADA audio interface. Also, if your DAW system has a built in-mixer (which most do), you don’t need a physical mixer (the mixer in your recording software will do the same thing digitally as a real life mixer will do in analog.)


How to Get your USB Mixer up and Working


The process of connecting your USB mixer into your computer will vary depending on what kind of computer you have. So we’re going to look at that connection process for both MAC and PC.


MAC USB Mixer Set Up Configuration


  1. Plug in your USB mixer USB cable into the USB port on your MAC computer.
  2. Click on the apple logo in the top left corner of your MAC screen
  3. In the dropdown menu, click on system preferences
  4. When the system preferences box appears, find and click on the sound icon
  5. From here, select the output and input
  6. You should have the option of selecting built-in-microphone or USB Audio Devic On a MAC, it may even read the manufacturer name of the device (ex: TASCAM or BEHRINGER.) Select your USB Mixer as the default input and output.


PC USB Mixer Set Up Configuration


  1. Plug your USB mixer USB cable into the USB port in your PC computer
  2. Windows should automatically recognize your device as “USB Audio Device” or as “USB Audio CODEC” – and it should automatically install any necessary drivers
  3. If your PC does not automatically install the needed drives, go to your USB Mixer model’s website and download the drivers from the manufacturer’s website
  4. When you connect your USB mixer for the first time, it will automatically be assigned as the default device for the playback sound (output) on your computer. Therefore, all of the sound on your comp will be sent to the mixer through the USB cable.
  5. You should now be able to open any recording software programs on your computer, and you should now be able to play and record through your mixer.
  6. To manually change your PC’s default sound device, go to start, settings, and then control panel and right click (or double-click) sounds, speech, and audio devices link. A dialogue box should appear. Once it does, click on the audio In the pull-down bar, you’ll read sound playback, and in the dropdown menu, you should see USB Audio Device. Select this, so it becomes your default preferred device for sound playback. You can do the same in the below section that reads sound recording, and in that dropdown menu, you can select your USB audio device. And now, your mixer should be the default input and output sound for your computer.


Concluding Remarks


A USB Mixer will perform similarly to an analog (non-USB) mixer, in that it will still mix your channels together in one track while you record. However, now with the USB technology, you don’t need an additional audio interface (if you need the use of a mixer while recording.) USB Mixers are an excellent addition to your home recording studio set up, most especially if you like live recording with your band or drum kit. And now you should be well versed in how to connect your USB to your respective computer, and how the USB Mixer functions during live in studio recording.

As you’ll have learned thus far, however, it is not totally necessary to have a USB Mixer as a part of your home recording set up. If you are a singer-songwriter who records one instrument at a time (your voice and then your acoustic guitar, for example), you won’t require the use of a USB Mixer, but rather the use of a standard audio interface (with a high quality pre-amp inside.)

Rob Wreglesworth

Rob has come to terms with the fact he will probably never be a famous rock star....but that hasn't stopped him from writing and recording music in his home studio. Rob has over 15 years experience of recording music at home.

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