Basic Tips and Tricks: Post Production Audio Enhancement 1.0 (Patreon)

Hello, Patrons! This is our first basic guide for post-production audio enhancement. 

We've already talked about some of the things you can do before recording to make your raw audio sound as clean as possible (See: Making the Most of Your Set-Up and Working With a Shitty Microphone Instead of Against It), but now it's time for a quick and dirty run through of some little tweaks that may enhance your finished product!

Before we start, I want to say that this is not the only way to do this, it's just the series of steps I've been using for the past several months to get the best results from my own audio set-up. I've also titled this post "Audio Enhancement 1.0" because, well, I anticipate my methods will change over time as I upgrade my equipment, learn more techniques and so on! (My new microphone is already leading to some little changes.) 

I am not, by any means, a professionally trained audio engineer--and even if I were, every pro worth their salt in any industry is humble enough to realize no matter how much you know, you can always learn more about your craft. 

But! I still want to share what I already know; every little bit helps, after all!

This tutorial is also specifically for Audacity, so you may have to adapt it to other programs if you use Adobe Audition or something like that. I will also be linking to the official Audacity documentation throughout, so that if you want to do more thorough reading on each of the tools/steps, you can! This is intended to be an overview, with an emphasis on Audacity users who are just starting out, but don't feel limited by my simplistic explanations! Dig in and learn even more if you want to.

Now, let's get into it!

Before Recording: Make sure your recording space is sound treated to the best of your ability and means. A professionally treated, expensive af sound studio is wonderful, but I promise you even the recording under a blanket will take you far. The cleaner your raw audio, the less heavy lifting you'll have to do in post-production.

For instance, if your raw recording is full of background noise, and you have to rely on mechanical noise reduction to reduce it, the quality of your vocal performance will suffer. The more frequencies that noise reduction has to strip out, the less depth and complexity your voice will have; the cheaper your microphone, the less depth your voice will already have, so we want to keep as much as possible in post production. 

Overusing noise reduction can damage a vocal track, making it flat and unpleasant to listen to. Avoid that by making sure your recording space is as  good an acoustic environment as you can manage!

I also suggest duplicating the audio track you want to edit before applying these steps, so that you can more easily see and hear the difference between the initial recording and the one that goes through this process. (It's also good to have a back-up, just in case of misadventure! You can always hit Edit > Undo, of course, but I like being able to compare tracks, myself.)

And now...Basic Post-Production Enhancement!

1: Noise Reduction

Once your audio is as clean as possible, it's time to apply Noise Reduction. This will strip out background noise that your microphone may have picked up that your ears didn't!

First, find a portion of audio that contains an uninterrupted segment of background noise to highlight. (I like to intentionally record about ten seconds of the room before I begin performing, just to make this step easier in post!) 

What you're looking for is something that is just the solid hum of your recording space, a section of your audio that has no vocal, no breathing, no mouse clicks, nothing like that. Once you find it, click and drag to highlight it!

If you're struggling to find a suitable selection of noise because your background noise is hard to hear, you can raise the gain to find it better. This basically adjusts the volume of everything in the vocal track to an extreme degree. Be sure to turn down your master volume so you don't blast your ears, though! And once you find the noise, remember to return the gain to its original setting of 0.

If you don't know how to raise the gain: there are two sliders on the left side of your vocal track:

The top slider, marked with - and + is the gain, while the slider below is the audio balance--audio output for the left or right side of your speakers/headphones, etc. For now, we want the gain! Slide that all the way to the right, then hunt around in your track to find a solid section of noise!

Once you've got your noise highlighted, select Effect from the top menu and choose Noise Reduction from the list of options.

The following window will pop up. Select Get Noise Profile!

The window will vanish, but that's okay! It means Audacity has identified the noise you want to filter in the track. Now, you want to take that little sample of noise out of the entire track, so highlight the whole thing with CTRL + A.

Return to the Effect menu, select Noise Reduction again. The pop-up will return!

This is where we'll adjust how strongly we want Audacity to filter the background noise. Too much noise reduction and your vocal may be damaged; too little and this will all have been for nothing!

These are the settings I personally use and recommend. Your needs may require higher sensitivity, but this is a good starting point if you've never used Noise Reduction before. Make sure your settings match these and then hit OK.

Your track will now be stripped of (most!) background noise!

2: Adjusting the Filter Curve

Filter Curve is a tool that is used to automatically equalize different frequencies in a vocal track; you can keep high frequencies from being too high, etc. There are many ways to alter the sound of a track just using filter curve to get different special effects, like creating a telephone or walkie talkie quality and such. 

What we're going to do is a very basic alteration that will reduce the less pleasant aspects of high and low frequencies in your voice, while retaining everything between.

Select your entire vocal track with CTRL + A, and return to the Effects Menu to select Filter Curve.

A window will pop up that looks like this:

(If your filter curve isn't flat like this one, simply select Manage > Factory Presets >Defaults on this window to reset it.)

That center line is the filter curve! And it can be altered if you click along it and drag the line to different points on the scale. 

The numbers along the bottom are the frequency of your track, while the vertical numbers are the decibels. The lower the number, the lower the frequency/volume, and the higher the number, the higher the frequency/volume, respectively. You can zoom in and out on the scale with the sliders on the right hand side, if you want to more finely tune where the filter curve line sits.

Personally, I have two different filter curve settings I use to enhance my audio and I'll share both with you. The first is very simple and good for beginners who want their audio to sound a bit better:

The line for frequencies under 100Hz is set at about 4dB, while frequencies over 30000Hz are set at 6dB. Everything in between stays at baseline! This ensures that your lower frequencies and higher frequencies aren't too high or low.

Once your filter curve looks like this, simply click OK and Audacity will apply the curve to your entire track.

This is a good, solid, general setting if you're just starting out (I finally figured out how to use it properly sometime last spring, because I'm a dingus who didn't follow directions properly for a couple of months ^^;) and as you familiarize yourself with the various qualities of your voice and the editing tools at your disposal, you may eventually tweak it to work for you even better!

A Brief Aside:

The second setting I use is specifically tailored to making my voice sound richer to my ears, but I'll share it anyway just to give you some idea of what I mean when it comes to adjusting the curve to better fit your voice's needs:

The lower frequencies of the filter curve remain the same, but the higher frequencies peak from 2000Hz + 6dB, then drop down to 30000Hz + -2dB. In my case, I find this setting greatly reduces any crispy, unpleasant sibilants or shrill  tones in my performances--especially those where I'm using a higher vocal register. It makes editing a lot easier for me sometimes as it solves many little finicky problems with a track at the touch of a button!

I switch between these two particular curves quite often, depending on what the audio in question requires to sound its best. 

3. Amplification Pt. 1

Once you've applied the filter curve, it's time to Amplify your audio! We'll be doing this twice during the post-production process, once to increase the amplification across the track, and once to reduce it to make sure your audio sounds nice and even.

For now, let's increase the dB!

Be sure your desired track is highlighted, and return to the effects menu to select Amplify.

A window will pop up with a couple of boxes and a slider.

The top input box is the important one, so you can ignore the other. 

When the window pops up, the numbers you see in those boxes will vary. What we want on this first pass at amplification is the default amount that Audacity determines is appropriate for your track, so on this window select Manage > Factory Presets > Defaults to make sure that's what will be applied. Then hit OK!

4. Compressor

Our next step is using the Compressor. A compressor basically squeezes an audio track into a specific dynamic range; the differences between highs and lows in a recording become less stark, farther voices become as clear/loud as near ones, things like that. Think of it as a leveling off of sorts for your full track.

Once again, make sure your track is selected with CTRL + A, and return to the effects menu to select compressor.

At first glance, you'll get a very intimidating pop-up window with lots of settings!

Don't panic! Just adjust the sliders and make sure those settings match these:

• Threshold: -30
• Noise Floor: -50
• Ratio: 5:1
• Attack Time: 0.10
• Release Time: 1.0

When you've made those changes to the sliders, your compressor and its little curve should look like this:

Once that's done, hit OK!

5. Amplification Pt. 2

For the final step in the process, we're going to use Amplify again! But this time, in a slightly different way. After making sure your track is highlighted, go to the Effects menu and select Amplify:

The window will pop up again, of course. But this time you're going to put a number into the top input box, to tell Audacity the maximum dB volume your audio will be allowed to reach at any point in the track. The setting I use (and suggest) is -3, like so:

With that complete, hit OK!

And...you're done!

After using all of these steps, your audio track should sound cleaner, richer, and more professional. 

You should also be able to better hear any little assorted sounds that slipped past noise reduction (breaths, clicks, etc.) and cut them out! You can do that by hand in various ways--using Amplify and a setting of -50 a couple of times to basically make them too quiet to hear, snipping out the sound entirely--or you can use more sophisticated tools like Noise Gate. You can also reduce sibilants with a De-esser or manually as briefly outlined here!

I hope this tutorial was helpful in some way! I know these steps definitely upped my own game when I started producing audio and learned some of them from this nifty fella over yonder and I hope they do the same for you. Good luck out there!

xoxo,

Velvet