In the twenty-first century, the outboard mixer is no longer a necessity, although many people will always use one. In professional recording studios, outboard mixers are an essential, irreplaceable part of the studio. Even as the technology landscape continues to change, the outboard mixer in some form or another refuses to go away.

The word “mix” is defined as combining or blending into one mass or mixture. In the case of recorded audio, a mixer serves as a control over many individual sounds, or channels (tracks). A mixer has two uses: The first is to manage many inputs of sound and help to route them into the recorder, including setting the appropriate recording input level and preamplifying microphones and instruments. The mixer is also used after recording to provide balance and EQ, add additional signal effects, and provide a final master mix of your sound.

Do You Even Need a Mixer?

Twenty years ago, you had to have an outboard mixer, because there was no way around it. These days, especially for home recording, you might not need an outboard mixer. If you're using a studio-in-a-box, where the unit has a mixer section built in with effects and EQ, you can get away without an outboard mixer, because all its functions are replicated on the unit. All of the cassette tape-based multitrack recorders provide some sort of mixing control, even if it's just volume and pan controls. For computer recording, every major brand of recording software provides a virtual mixer that allows you to change the balance of audio tracks and much more, all with your mouse. With a virtual mixer, you can even record the movement of the on-screen faders to be played back automatically during the final mix down (when everything is recorded to a single file) after you've finished mixing.

If you like the idea of moving volume sliders with your hands while using a computer, you can use “control surfaces” that move the onscreen faders. You can find more about control surfaces in Chapter 17.

Benefits of Using an Outboard Mixer

If you are running a standalone digital recorder like an ADAT, DA-88, or other standalone hard-disk recorder, you won't be able to function without an outboard mixer, because those recorders provide no control of the sound during or after recording. The mixer is your link to effects, EQ, and all volume manipulation. Having an outboard mixer is an essential component in these cases.

But even if you have the ability to mix built into your equipment, you might want a separate outboard mixer. Many studios-in-a-box and computer-recording interfaces aren't exactly generous with the number of inputs and outputs they provide. Countless studios-in-a-box tout eight channels or more of simultaneous recording, yet provide only two microphone inputs. So what do you do when you want to record more than two channels of microphones? What do you do when your computer-recording device has two only inputs total? In this situation, an outboard mixer is going to come in really handy.

The outboard mixer will allow you to take eight microphones and mix them down to a stereo (2-track) mix that you can bring into the computer. That works great for the computer interfaces that have only two inputs. The only downside is that you lose the ability to change the volume of individual channels after you record. Whatever you set on the outboard mixer and send to the recording device or computer is what you get. That's not a bad thing if you get a good mix on the board. Some studio and live recordings are still done this way.

For recording devices that give you only two microphone channels and additional line inputs, you can take advantage of the microphone preamps that many, if not all, outboard mixers have built in. You can plug in additional microphones to the mixer, preamplify them, and send their individual outputs from the mixer to the line inputs of the recording device. This is the easiest way to increase the number of microphone channels. Not only can buying an outboard mixer be cheaper than buying a new recording device or additional microphone-preamplifiers, but having one comes in handy if you play live or have to mix sound. A few companies, such as Mackie, Behringer, Alesis, Nady, Carvin, and Soundcraft, make small outboard mixers appropriate for home studios.