Almost everyone knows that a microphone picks up sound and converts it into audio. This audio is recorded by a dedicated audio recorder or a camera. What’s a mixer, then?
What does an audio mixer do?
A portable mixer comes between the microphone and the recorder, to do the following:
- Amplify, lower or equalize the levels from the microphone(s).
- Control gain from the microphone(s).
- Add filters or effects to the audio from the microphone(s).
- Input multiple microphone sources and provide separate (or one) control for all of them.
- Mix the multiple audio feeds to stereo or mono.
- Reroute multiple output signals to recorders, cameras, etc.
- Provide a reliable monitoring platform.
- Control headphone volume.
- Controls easily accessible to the Production Audio Mixer, as opposed to having to stand next to the camera.
- Feed multiple audio recorders.
In simple terms, a mixer is to a production audio mixer what a camera is to a director of photography.
A good mixer could have the following properties:
- Be small and light-weight.
- Have more than one XLR port and multiple input connector-types.
- Offer separate gain controls to each microphone.
- Must run on batteries and offer phantom power.
- Offer full control over the mix and panning controls for stereo.
- Offer the basic filters, preamp, effects, etc.
- Offer a reference tone generator to help the editor distinguish audio between takes.
- Offer reliable and accurate metering.
- Offer headphone levels control.
- Offer quick access to all controls, especially levels.
- Offer full control over the levels of each output individually.
- Have the ability to ‘fold back’ so you can hear what the camera is recording.
- Have multiple output options.
- Support wireless systems.
Here are five dependable audio mixers for field recording. I have only listed mixers that offer at least three XLR connectors. If you’re investing in a mixer, and can only afford one, go for the one with the most number of input connectors and the best preamps.
Beachtek DXA-SLR PRO HDSLR Audio AdapterPrice: $439
Shure FP33 3-Channel Stereo MixerPrice: $1,328
Sound Devices 302 Portable 3 Channel Field MixerPrice: $1,595
To learn more about field mixing and audio equipment, read the Chapter on Audio in the Comprehensive Rigging Guide.