Acx Audiobook Production Using Audacity

Section Overview: What You’ll Learn in This Section Preview 00:55

In this section of the course we talk specifically about ACX audiobook requirements. This short overview video of section two introduces the ACX requirements for each of the following:

• Room Tone

• Noise Floor

• File Length

• Sample Rates

• Bit Depth

• RMS Loudness

I introduce each of these terms to you here and define them and I'll show you where to set the ones that can be set in advance in Audacity as we move through this section. We'll return to these terms throughout this course where applicable. You'll find a link in the Resources folder to ACX's Audio Terminology Glossary.

ACX Standards for Room Tone, Noise Floor, and File Size Preview 03:24

Let's talk about the ACX standards for room tone, noise floor, and MP3 file size limits. ACX requires room tone in your audio, not silence. Room tone sounds natural whereas complete silence doesn't. In addition to room tone throughout your file, ACX requires a certain amount of room tone (with no speaking) at the beginning and end of your file. I show you how to add the required amounts of room tone to the beginning and end of your file later in the course.

We'll define noise floor as the amount of noise generated by a device (microphone, audio interface, computer, etc) with no signal present.

ACX Standard for RMS Loudness Preview 05:25

RMS loudness is the average loudness of your audio. High and low peaks in our audio are averaged to arrive at the RMS value. ACX requires an RMS loudness of -20dB and Audacity has a built-in feature that will set that perfectly each time.

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ACX Standards for Noise Floor, Sample Rate, & Mono vs. Stereo Preview 02:13

I introduce the ACX standards for noise floor, sample rate, and mono vs stereo in this video.

Setting Audacity Preferences to Meet ACX Standards Preview 05:32

We're about to start recording a fictitious audiobook in the next section so let's open Audacity's Preferences window and set up what we can ahead of time to insure we meet the ACX standards for sample rate, noise floor, and room tone every time we record. While we're in Preferences, let's talk about Punch and Roll Record because we're going to use it right away in Section 3.

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Section Overview: What You’ll Learn in This Section Preview 00:52

Welcome to section 3. This is where we start using Audacity and learn how to apply the different ACX requirements to our recorded audiobook chapter. After we record a short piece of audio and I show you how to fix a mistake on the fly using Punch and Roll Record, I take you through the manual process I use in the order that I use it. Then we'll build a macro together to automate the process and do the work for us. This is a huge time-saver and it adds consistency to our recordings from chapter to chapter.

Record a Track and Use Punch and Roll Preview 06:24

Let's record and make a mistake so we can fix it right away using Punch and Roll Record. This method of repairing mistakes as they happen allows us to stop our recording as soon as we make a mistake and punch in a fix right away before moving on.

The practice sample file is in the Resources folder. You'll need that for the assignments that follow. You'll also need Audacity version 3.0 to open it. Versions prior to 3.0 cannot open this file.

Don't worry that the audio level is low on this recording. It won't be once we level the RMS loudness. The manual process of showing you what I do one step at a time means that the audio is going to remain low while we work through those initial steps. But as you'll see in Lecture 14, the level is instantly boosted when we apply the macro so the level is never really a problem in real world production.

NOTE: The assignment for this lecture is in the Resources folder. All assignments are optional.

Applying Equalization Preview 05:13

After I record a file, the first effect I like to add in post-production is equalization. This is my first step in anything I record. I want equalization on it first because I want it to factor in on subsequent processing. That's just my personal preference. Two of my Filter Curve EQ Presents are in the Resources Folder for this lecture. I use the RODE NT1 for ACX (in my walk-in closet) and the RODE NT-USB-MINI primarily for YouTube videos and podcasting. There's only a slight variation in the settings between the two, but these settings work good for my voice. Feel free to use these as a starting point for your setup if you like and then adjust the settings to fit your needs.

NOTE: The assignment for this lecture is in the Resources folder. All assignments are optional.

Compression and RMS Loudness Preview 05:49

One of the things we don't want is for those listening to our audio to have to be adjusting the volume up and down as they listen. We basically want them to set it and forget it. Applying compression and RMS leveling to our file is a win-win for making sure our audio loudness is consistent from start to finish. Compression brings the loud and quieter parts of our audio closer together without any loss in the dynamic feel of the audio. Words or phrases that we emphasize will still be emphasized but without drastic differences in loudness. RMS leveling brings the entire file into the ACX specifications for RMS loudness, adding even more loudness consistency to our audiobook chapter.

I use RMS Loudness in place of Normalization when recording for ACX.

NOTE: The assignment for this lecture is in the Resources folder. All assignments are optional.

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The Limiter, De-Clicker, and ACX Check Preview 09:39

Depending on the loudness of our original recording, applying RMS Loudness can easily result in peak audio above -3dB and even clip our audio a little. Because I automate all of this using a macro (that's the next lesson), I can't always see the results of RMS Loudness so I add a limiter to make sure I don't exceed -3dB peak audio. I set my limiter to -3.5dB to give myself a little more headroom.

I use the De-Clicker on everything I do. I makes me sound better than I am by eliminating mouth sounds and mouth clicks. If you're applying the De-Clicker on a long chapter or piece of audio, it's going to take a while to run but it's well worth it. Go grab your favorite beverage while it's running. You'll be glad you ran it.

NOTE: The assignment for this lecture is in the Resources folder. All assignments are optional.

Letting Macros Do The Work Preview 09:09

Let's speed this process up by making a macro that can do the work for us in a fraction of the time. The macro we build in this lecture is in the Resources folder of this lesson. Import it into your copy of Audacity and make it work for you.

NOTE: The assignment for this lecture is in the Resources folder. All assignments are optional.

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Section Overview: What You’ll Learn in This Section Preview 02:48

Now that we have a good file that passes the ACX Check in Audacity, let's do some needed content editing. We haven't done anything with this file yet in terms of taking care of loud breathing, weird pauses, or other audio anomalies that occurred along the way as we recorded. So let's do some of that and then export it for ACX.

Cleaning Up Breath Sounds with Punch Copy/Paste and Punch Paste Preview 07:36

One way to eliminate intrusive or loud breath sounds between phrases is to replace them with good room tone. We do this using two of the plugins I provided you: Punch Copy/Paste and Punch Paste.

NOTE: The assignment for this lecture is in the Resources folder. All assignments are optional.

Cleaning Up Breath Sounds with Attenuation Preview 04:32

Breathing is normal. We all do it. Eliminating breath sounds altogether may not always be best. Instead of replacing breath sounds with room tone, we may choose to reduce them instead by attenuating them.

NOTE: The assignment for this lecture is in the Resources folder. All assignments are optional.

Final Cleanup, ACX Check, and MP3 Export Preview 10:45

Let's get our audiobook chapter out the door and on its way! ACX requires that our final MP3 file have a bit rate of 192kb/s (192,000 bits per second) or higher. Bit rate (or as Audacity calls it, Quality) is a reference to how much of the original sampled information we want to retain in our conversion to MP3. Remember, our original sample rate was 44.1kHz or 44,100 samples per second. That was an uncompressed, lossless WAV file. But now we have to convert it to a compressed, lossy MP3 file for streaming. Bit rate is referring to how much of the original sampled information we want to use as we convert it to MP3. Typically, the higher the bit rate (Quality), the better the reproduction. ACX requires a minimum bit rate of 192kb/s.

After exporting our final MP3 file, I like to bring it back into Audacity and run ACX Check one last time before uploading it to ACX. You'll find a link to the ACX Audio Submission Requirements in the Resources folder.

NOTE: The assignment for this lecture is in the Resources folder. All assignments are optional.

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Congratulations and Additional Resources Preview 01:00

Congratulations on completing the course. If you haven't already, please leave me a rating and review. Those help me to know where I can improve this course and it helps prospective students make an informed decision when considering this course. Don't forget to grab your Certificate of Completion and take a look at the additional resources I've provided for you in the Resources folder. Each of these people have been a valuable resource for me so I wanted to share them with you. The last one in the list is my deep-dive course into Audacity.

What's New in Audacity Version 3.1? Preview 09:36

Version 3.1.0 of Audacity has been released with significant changes, so let's review them.