Echo. A side effect of Hum Removal?

[Joe Marler]

I’ve sometimes heard an echo-like artifact when using FCPX audio noise reduction. If you turn down the effect intensity it will go away but the noise reduction decreases also. The only time I use FCPX audio noise reduction is by accident.

My documentary team uses iZotope RX7 Advanced, which in skilled hands can do wonders. We don’t use it as a plugin but as a stand alone app.

CrumplePop makes the FCPX plugin AudioDenoise, which is simpler to use. It works OK but it’s nothing like iZotope and basic version of iZotope isn’t much more money and it’s the gold standard. It can usually remove easy cases like hum, truck back up alarms, etc. with no discernable artifacts. Removing broad-band crashing sounds ( someone drops a box or slams a door during dialog) is much more difficult. Note iZotope is like Photoshop for noise removal — it requires an experienced technician for best results.

https://www.crumplepop.com/product/fcpx-premiere-plugin-audio-denoise/

https://www.izotope.com/en/products/repair-and-edit/rx.html

[Xavier Paredes]

Thanks for your reply. I am, however, looking to see if someone else has experienced the echo “side effect” when ticking the Hum Removal box.

FYI: I’m using FCPX 10.4.1

Thanks

Xavier

[Joe Marler]

[Xavier Paredes] “looking to see if someone else has experienced the echo “side effect” when ticking the Hum Removal box.”

I haven’t experienced this except when both noise removal and hum removal were accidentally both selected. Hum removal by itself didn’t cause an echo effect in my experience. For the simple cases where I used FCPX hum removal, it worked very well.

However the FCPX hum removal algorithm is doing something more complex than simply notching out a 50/60 Hz hum and harmonics. I tested it on a more complex case with many audio harmonics from stadium lighting and it also worked OK there, and without obvious artifacts. Maybe there’s some kind of source material that triggers an echo side effect. This was on 10.4.4.

[Mark Suszko]

It might only be a semantic difference, but I think I’ve heard the echo you’re talking about. However, I’d characterize it more as a “ringing”.

[Xavier Paredes]

Here’s exactly what I hear:

https://www.dropbox.com/s/s6t4ohcitk1xlsr/Hum_Removal_problem.mp4?dl=0

Xavier

[Jesse Freeston]

I am having exactly the same problem.

60Hz hum removal masterfully eliminates the hum of a vending machine/fridge but adds an echo to the voice of the person who is speaking.

Sound is definitely an echo.

Using FCPX 10.4.5

Jesse Freeston
Documentary Filmmaker/Editor/Shooter

[Sebastian Leitner]

yes, also with the 50hz hum removal, voice gets an echo in 10.4.5
hum removal is not meant for noises like fridge/compressors etc.

it’s meant for power line hums in either 50 or 60hz, which occur with analogue audio connections other than XLR and/or badly isolation and/or using the same power plug extender for different analogue devices.

it doubles the signal and moves it a wavelength to make use of destructive interference of that frequency. so, if it’s not the power line hum it won’t work and adds echo!

i see that sometimes fcpX activates it automatically because it thinks it hears” a power line hum. most of the times, this is wrong and denoising is the better way to go.

to get rid of compressor/fridge or similar “hums” use a lowcut/highpass filter instead! because those frequencies are different from 50/60hz and also vary in wavelength.