Remove Low-End Noise from Sound Effects for Video
Since commercial and corporate video production budgets can often be small and executed under a short time frame, the recorded sound may suffer. During post-production, as a result, producers may encounter some terrible audio problems. One common dilemma is a low-end noise or hum that permeates dialog and other ambiance recordings.
Certainly many of the software plugins on the market that filter out noise work very well. Though, under a tight deadline, it may prove impossible to seek out, purchase, and learn the functions of whatever new plugins you may find. As an easy alternative, use the standard eq and reverb plugins provided in your video or audio software.
Use these procedures in tandem with your default plugins to help rid your audio recording of unnecessary and distracting noise:
Use a Single Band EQ first to cut out the unwanted rumble. A single band EQ will filter out all audio above or below a specified frequency. You can cut out, for example, all frequencies below 80 Hz in order to erase much of the rumble, which occurs at 60 Hz, without harming dialog tracks.
Next, target a very small width of the offending sound spectrum by using a Parametric EQ and “notching,” which decreases a certain frequency and its octaves such as 80 Hz, 160 Hz, and 320 Hz. One preserves the surrounding audio by being able to target a small area of audio.
Third, use a Parametric EQ to boost the desired audio slightly. By doing so, it will be prominent over the noise and take the listeners attention away from the unwanted hum. For example, boost a bit at 5 Khz to raise the human voice over a low hum.
Fourth, once the low end has been cut or minimized, use a bit of reverb on the entire mix. This creates a sonic wash of sorts and reduces the “tin can” effect that can be created by cutting out the low end.
Following the above strategies may not completely erase all problems associated with bad audio, but they can improve the quality of the product when unwanted noise and dialog are competing for attention in the mix.
