Audio mixers can offer control and improve video sound if used properly.
A weak audio signal from a mixer to a camcorder usually has to do with improper camcorder or mixer settings. Even if you have used the same microphone and mixer with another camcorder successfully, video camera brands and models can vary greatly in their audio circuitry, setting parameters and consequent external device needs.
Impedance Mismatch
Low-impedance microphones -- "balanced" or "low-z" -- are used exclusively in professional audio applications for the ability to run long cable lengths with low noise. High-impedance microphones -- "unbalanced" or high-z" -- are used primarily in consumer applications where cable lengths are shorter. While most mixers have the built-in capability of converting low-z mics to high-z output signals, some do not offer this feature. The result of connecting a low-impedance mic to a high-impedance mixer and camcorder will result in a weak audio signal. Ensure that your mixer is capable of converting low-z mics to high-z signals for best audio results.
Line and Microphone Levels
Some camcorders and mixers include switches for mic- or line-level input signals. Line level devices, such as CD or MP3 players, include signal boosting circuitry and require no additional sound level boost from the mixer or camcorder. If a microphone is plugged into a mixer with the switch set to "line-level" the result will be weak sound. Check for a mic- or line-level switch or specified input on the mixer and ensure that it is in the "mic" position, or the mic is plugged into a mic-level input rather than a line input.
Camcorder Settings
If the mic and mixer seem to be compatible and set up properly, check the camcorder's audio setup in the menu. Many camcorders do not recognize the difference between line- or mic-level automatically and need to be set accordingly. Depending on your mixer (some output as line level and others as mic level), you may have to perform an audio test with both settings to determine which will provide the best audio. Also check that the camcorder's audio input level is set to "auto" rather than "manual" to compensate for differences in sound levels and to prevent weak signals.
Connections and Other Audio Considerations
Be sure that all microphone, mixer and camcorder connectors and cables are operational and are of the correct type. Local camcorder dealers or repair shops can check the operation and compatibility of these components if you are not sure. Other considerations that could cause weak sound include improper use of the mixer, weak or dead batteries installed in microphones that require them or simply being too far away from the audio source during recording. Read the mixer operation manual thoroughly, ensure mic batteries are fresh and place external microphones as close as possible to the source.
Tags: mixer camcorder, audio signal, best audio, cable lengths, camcorder audio, converting low-z