No piece of gear is more closely associated with the recording studio than the mixing board. Historically, that's where the engineer spends most of her time working. A mixing board is simply a device that takes many individual audio channels and mixes them to a stereo left and right output. (Many mixing boards have more than a single stereo output, but for a general description, think of a mixer as a device that sums many signals to a pair of outputs.) Mixing boards also allow you to preamplify microphones and adjust equalization (EQ). EQ is further explained in Chapter 15. Despite all this, mixing boards are no longer a necessity for everyone. Who needs one? And how do you benefit from having one?

Why You Might Want a Mixer

If you have a standalone recorder, you need a mixer. Standalone recorders only record and play back. They don't set levels or provide EQ; they just capture sound. So you need a mixer to control audio levels. This is why the mixer is so closely associated with the recording studio. Only in recent years, with the studio-in-a-box and computer software, have mixerless setups become possible. Traditionally, every recording device was a simple record and playback machine; the mixer wasn't optional. Even as computer systems become more commonplace, some engineers still like having the control a traditional mixer provides, instead of mixing with a mouse.

Let's say you need to record three microphones and you only have two inputs on your recorder. You might use a mixer to help you overcome this limitation. As an example, one input could be used for one of the microphones and you could combine the other two microphones through the mixer. However, you lose the ability to control the volume of the individual microphone signals, so if you're going to do this, be very careful to get a great-sounding mix of those channels before you record anything for real.

If you're going to combine your microphones, be sure you trial record each track to get the best sound before you commit to the final recording. Once it's recorded, you can't change it. This is why it's important to get the right number of inputs on your recording device so you can avoid these difficult compromises.

You may want to use a mixer if you've had experience with one and feel comfortable with it. You might also want a mixer if your recording device has limited inputs. Suppose that you have an eight-input recording device; you can record a maximum of eight channels at once. (You can overdub more than eight, but eight signals at once is your limit for recording.)

If you're recording a live band and need more than eight signals, you might want to use a mixer to pare down some of them. For instance, instead of a drum kit taking up six valuable available inputs, you can use a mixer for the drum tracks. You can take those six drum microphones and mix them down to four tracks so they take up fewer inputs. Maybe you can combine the tom toms into a single track and save a channel. The only downside to this is that whatever gets mixed into one channel is there for good. Using the tom toms as an example, if you decide later that the right tom is too loud, there's no way to change the balance—you can't unbake a cake!

Why You Might Not Want a Mixer

If you're going the route of the computer-based studio, you likely won't need a mixer. You may find that USB and FireWire interfaces sporting eight or more inputs give you enough simultaneous inputs. In fact, most home recording studios rarely need to record more than eight signals at once. Computers also sport amazing virtual mixers for controlling levels after recording. You can even use a control surface if you enjoy mixing by moving knobs and faders rather than a mouse. There's more on these in Chapter 17.