Mix and Match

Hal Robertson
February 2005

So, you're ready to buy a new audio mixer. Good for you! An audio mixer is a powerful tool in the video producer's bag of tricks. Not only will it allow you to combine multiple audio sources, depending on the model, you can also adjust tone, volume and interface between a wide variety of inputs and outputs.

This buyer's guide contains a large list of manufacturers and models with a sizeable range of applications and prices. A survey of mixer options, features and benefits should help you find the perfect model to fit your production style and requirements.

As you consider the smorgasbord of options before you, think about how you'll use an audio mixer. If you primarily shoot one style of video, that will also shape your decision. For instance, live concert events could require many inputs, while simple interviews or round-table discussions might only need a handful. Don't forget about how you'll use a mixer back in the edit suite, not only as an interface for a voice-over microphone but for other audio devices such as your sound card, powered speakers or that turntable you use once a year. Mixer inputs range from XLRs for microphones to ¼" and RCA plugs for line-level sources. Some mixers even use terminal strips or Euroblock connectors for bare wire hookup. One popular option in recent years is the stereo input -- a pair of inputs controlled by a single fader or knob. These are great for music sources such as CD, MP3 players and cassette decks. If you use condenser microphones, make sure your mixer supplies phantom power.

On the output side, mixers include the same connector options: XLR, ¼", RCA and even Euroblock. Some mixers offer microphone level outputs while others offer only line level. For the ultimate in convenience, look for switchable outputs that allow you to feed whatever level you need for a particular situation.

Once the audio is in the mixer, you have even more options. Many mixers offer the option to adjust the gain of line and microphone inputs. Not just a volume control, the gain option allows you to easily match the volume of several inputs to make mixing and processing easier. Your mixer choice might also include an overload or clip light that flashes when you have the gain set too high -- very handy for getting audio levels under control. Another handy option is the cue or solo button, allowing you to monitor a single source in the headphones. Equalization or tone control can be as simple as a single knob or as complicated as three or four-band parametric control. The more sophisticated the better from a control standpoint, but consider the extra complexity and desktop real estate the extra knobs add to the mixer.

Your new mixer may include an auxiliary send and return for creating an alternate mix or sending to an external processor such as a reverb or echo device.

While some mixers offer main volume sliders, many small mixers only provide knobs for volume. Technically, there is no difference in function, but it's quite easy to move a handful of sliders at the same time while each knob needs its own hand for control.

Most mixers today include some kind of metering for a visual indication of volume. Meters can be old-school needle type or the more modern LED ladders. LEDs respond to peaks quicker while needles tend to show an average level. While not every mixer includes metering, it can make the difference between clean audio and a distorted mess.

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