This is a popular question among many aspiring/startup bedroom producers. Do we really need one?
Mixers are multi-faceted pieces of electronic hardware with several main functions which include receiving analog and digital audio signals, combining (or summing) these signals, controlling individual levels and frequencies of said signals, and outputting them to broadcasting and recording devices. It is also classified as a mixing panel, soundboard, or audio converter. On the other hand, A digital audio workstation (DAW) is an electronic device or application software used for recording editing and producing audio files. DAWs come in a wide variety of configurations from a single software program on a laptop, to an integrated stand-alone unit, all the way to a highly complex configuration of numerous components controlled by a central computer. Regardless of configuration, modern DAWs have a central interface that allows the user to alter and mix multiple recordings and tracks into a final produced piece.
So in order to be able to decide what to do, whether you are podcasting or working on technical audio output, it helps to consider the needs of each tool at first.
Now, why can't you just use a USB microphone and directly connect it to your computer, you might ask? An audio interface is specifically designed to take the sounds from your live audio sources and send them to your computer for playback or recording — and unlike the built-in 3.5mm microphone jack or sound card on your computer, it actually preserves the quality of the sounds, which is essential if you want professional-sounding audio. Mixers are especially useful for live performances and other situations where there is a need to modify the audio coming from multiple microphones and instruments (that are being played simultaneously) to create a clear, solid mix. With a good mixer, there’s no need to worry about a particular sound overpowering others.
Then again, your decision mainly depends on your preference and long-term goals. If you have the budget, space, and patience for it, you can always get both, especially if you want to try your hand in experimenting with a mixer and discovering everything that it can do to transform your sound. If you’re interested in eventually becoming an audio or record producer, then it’s definitely worth the investment.