19Jul DSLR Audio editing tips for post production: Auto Gate
A simple and easy way to remove background noise from a clip is to use a noise gate. This is basically a method used to reject audio above or below a set threshold. It can be very handy if you are trying to remove background noise from a given audio track. Set the lower threshold to something above the noise floor and below the lowest need audio level. Anything below that threshold will be removed from the audio clip, that way whenever someone isn’t speaking into the microphone you have silence.
Adobe hides the noise gate feature under the label “dynamics” while FCP editors can find the feature under the label “AUDynamicsProcessor”. If you don’t use either of these programs and your editing software doesn’t have this feature you can export your audio and perform the same task in free programs like Audacity. For a step by step guide in Audacity you might want to take a look at this.
July 19th, 2012 at 9:23 am
Hey DeeJay,
Having picked up the Tascam Dr07 MKII recently, this is really helpful! And having just received Premiere CS6, one thing that drives me crazy is that I can’t see the wave lengths on the audio in the timeline. How do you activate it?
July 19th, 2012 at 9:54 am
Not sure Chris, I’m still running CS5.5 right now. I’m waiting for the end of the year sales to upgrade.
July 19th, 2012 at 9:24 am
ThanksDeeJay! How do you show the audio meters in the timeline in CS6?
July 19th, 2012 at 2:53 pm
Chris, try hitting the little triangle arrow all the way on the left of the timeline, near the other track controls. It should make the track thicker and you should see the waveforms.
Thanks for this tutorial – I always used the high or low pass filter, I had no idea this filter existed.
July 22nd, 2012 at 3:31 pm
Aha! Thanks! That really makes it easier!
July 19th, 2012 at 3:05 pm
Also DeeJay, do you have any advice for trying to get a follow focus to work with a lens that has a very stiff (but not broken) focus ring?
July 19th, 2012 at 5:52 pm
I’ve seen a few people actually take the lens apart, wipe down the focusing parts, and put them back together with some success. Or you could use one of the leverage type focusing units that apply more force then most of the gear type options.
August 19th, 2012 at 2:59 pm
Not trying to be a jerky face; but if the noise gate is listed under the dynamic effects category, then there’s nothing “hidden” about that. 😉
August 19th, 2012 at 6:21 pm
Dynamic is actually the name they use for the effect, not a category, so hidden is probably close. Maybe obscured would be more accurate.
September 3rd, 2012 at 5:16 pm
I think you missed two important controls on your gate: attack and release. These settings relate to the amount of time that the gate takes to fade in and fade out the input. To short an attack will make the gate “grab” the sound, to long an attack will cut the first bit off. Using a slightly longer release will also help sometimes.
September 3rd, 2012 at 7:01 pm
That’s true with music but with speech the cadence makes attack and release less of an issue. If you set the gate level low enough, you wont notice the cut in audio in speech, but it will be very noticeable in music.