Low rolloff for speech
PUPOSE:
Low-rolloff is an equalization setting for Audacity intended to remove low pitched tones, thunder, rumble, church organ pedals and earthquake sounds.
USE:
Select the work to be corrected or a whole performance by clicking just above MUTE at the left of the timeline.
Effect > Equalization > Select Curve: Low rolloff for speech, Length of Filter: about 5000 > OK.
COMMENTS and NOTES:
Low rolloff mimics the 100Hz rumble audio filter used in Outside Broadcast, Field Recording and Location Movie Shoots.
It’s featured in the Shure A15HP microphone adapter
and it’s a standard button on many sound mixers.
It’s the most low pitch sound you can remove from a performance without most people noticing something wrong.
Some male announcers with low-pitch, rumbly, broadcast voices may notice their voice tighten slightly and some of the broadcast rumble will vanish. Those performances may need to be corrected by hand instead of pre-baked Low-rolloff.
Low-rolloff (and the earlier, custom LF rolloff for speech) rose to prominence in AudioBook recording because of a collision. ACX AudioBooks measures noise using Z protocol which includes rumble and tones too low pitched to hear. At the same time USB microphones became popular and many of them produce very low pitch rumble and noises by an accident of manufacture. So it’s possible to fail ACX Conformance with noises neither you nor anyone else can hear.
Low-rolloff removes those noises.
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LF_rolloff_for_speech.xml (299 Bytes)