Repairing Audio Signals to Improve Sound Quality & New Audio Assets


As I mentioned in my production blog for The Place Beyond the Pines our group had decided to record as much Foley as possible with the dialogue, having our voice actor wear a bag on his front as the actor did, and move accordingly to capture the right sound. This worked well, however, when I went to double the dialogue to boost the vocal presence, I didn’t actually want to boost too much of the background noise. I was looking for a clean dialogue track and knew I needed to do some editing and filtering to make that audio signal a lot cleaner.

To start, I added a noise gate to the single track to make sure no line noise was present. Moving to a space in the track with no dialogue, I adjusted the threshold fader until the activity light on the gate turned off.

Screen Shot 2015-08-25 at 5.15.53 pm

I then went through and adjusted the attack, hold and release settings on the gate. Obviously, a fast attack would be best for what I’m looking for. For the hold I settled at around 40ms, and the release I extended to 263.5ms prevent a choppy sound as the gate works in the track.

The next step was to add an expander to the track to improve the dialogue presence that we have recorded, without too much interference from any background noise picked up. For the expander settings I once again, set a fast attack (2.0ms) to have the expander cutting in as quickly as possible. The release this time was set much quicker than the noise gate, at 2.5ms. The rest of the settings would then be adjusted as I listen to the track and decide what sound I prefer. After giving the track a few plays, I settled on the following settings:

Threshold: -21.0dB
: 0.0dB

Upon adding these nifty tips to the duplicated dialogue I really noticed how clean the non speaking parts of the track became! Of course, I could then go through and slice up anything which was still prominent, but I’ve found that to sometimes ruin the blend of the track and can definitely end up making the cuts and clips stand out. I believe these tips could really be useful in cleaning up samples downloaded online as a lot of those tracks can suffer with noise and general cleanliness, especially after being converted or compressed too many times.

Here’s a snippet of the cleaned up track, as you can hear (or rather, not hear) it doesn’t sound like there’s a whole heap of movement going on in the background at all!

With the success of that process, I then decided to later apply it to the bag movement Foley we had recorded in a later Audient session.

The audio itself was pretty good, however, I noticed as I was lining it up to the film that the bag we had used definitely sounded too heavy and too thick for the visual we were receiving in the movie. The actors bag remains empty for a long time and is made from a different material, so I figured rather than rerecord with another bag (which may end up sounding off anyway), it would be better to take what I had, and adapt it to fit the image.

Here’s the bag audio before any adaptations:

The first thing I noticed was the deeper sound it was giving off. I definitely needed to lighten up the track, not only to make it seem lighter, but the bag also needed to sound smaller and made of cloth rather than leather. To fix this issue, I went back to the track added a pitch plug-in. Here’s the one that Logic Pro X had for me to use:

Screen Shot 2015-08-25 at 6.09.15 pm

First thing I wanted to do was set the semitones, cents, and mix at 0 as these were the adjustments I would be playing around with as I go depending on what I like. Going back to the move I swapped between listening to their sample and my own and began adjusting all the settings on what I was hearing. Here’s the settings I settled on:

Screen Shot 2015-08-25 at 6.20.06 pm

The only problem I had now was that I didn’t want the rattling of the zippers to be pitch shifted, as they were already quite high and light and the result of them being put through the shifter ended up sounding crazy! To fix this issue I simply went through and automated the pitch shifting to where I wanted it to take effect.

Screen Shot 2015-08-25 at 6.24.22 pm

Here’s the final result:

I definitely would’ve been happier being able to do this process with a slightly better pitch shifting program, as I’m not very convinced with Logic’s but unfortunately, this process took place at a time when I was away from my usual abode with a different laptop and couldn’t access a better DAW. Limited resources!



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