The High-Low Pass effect sets a limit above or below which frequencies can pass. High Pass allows frequencies above the limit and blocks frequencies below. Conversely, Low Pass allows frequencies below the limit and blocks frequencies above. Use High-Low Pass to do the following:
- Enhance or attenuate (reduce) a sound. For example, using High Pass can reduce traffic noise, which often is concentrated at low frequencies, while minimally affecting a voice recording. Using Low Pass can remove high-frequency sounds, such as static and buzzing.
- Change the focus from one sound to another over time. For example, in audio that contains both music and voice, you can fade out the music while gradually bringing in the voice.
- Protect equipment from potentially damaging frequencies.
- Direct certain frequencies to specific equipment. For example, use Low Pass to isolate sounds intended for a subwoofer.
To check the frequencies that you filter out, switch to the opposite Filter Options value and preview audio.
Cutoff Frequency All frequencies below (High Pass) or above (Low Pass) are removed. If the unwanted sound changes over time, animate this property. To identify the frequencies of unwanted sound, use the Audio Spectrum effect.
Dry Out, Wet Out The amounts of the original (dry) sound and delayed (wet) sound in the final output. Common values for removing frequencies are 0% for Dry Out and 100% for Wet Out.