How to Beat the Sound Effects Mastering Grind


A year and a half ago I sold everything I owned, jumped on a plane, and arrived in Southeast Asia. Why?

To capture field recordings, of course. I’ve travelled through Malaysia, Cambodia, Thailand, and Indonesia recording the sounds of the cultures in those places. I’ve wandered into obscure corners of Bangkok, Siem Reap, Kuala Lumpur, Denpasar, and other cities to find cool sound effects.

Now, almost 18 months after I began that trip, I am faced with a challenge: my hard drive is crammed full of raw field recordings that need polishing. There are thousands of files. They were captured from three microphones. It’s an overwhelming amount of data that could total hundreds of hours of audio.

I have a special plan for those field recordings that I’ll share with you later. In the meantime, there’s a more obvious problem: how does one transform thousands of field recordings into finished, listenable sound effects? What’s the best way to master bulk field recordings?

Today’s article shares techniques that help you tackle the mastering process efficiently to move those raw files from your hard drive into the ears of your listeners.

Please note: I explore this idea in depth. This post should take you about 12 minutes to read. If you’d prefer, you can email yourself a copy of the post to read later.

The Challenge of Mastering Sound FX

Mastering sound fx can be challenging even in the best scenarios. Why?

Well, mastering sound clips has significant challenges. It is:

  • Detailed. Polishing sound fx requires drilling down into the most minute parts of recorded sound to find the tiniest flaws: clicks, thumps, imaging shifts, and more. It cannot be done passively. It requires absorbed attention to hear and then solve these issues.
  • Creative. Fixing technical flaws is just the beginning of the mastering process. The best mastered files identify and highlight a sound’s unique flair and present that character to listeners. It’s not easy to balance fixing technical flaws with enhancing creative expression.
  • Repetitive. Field recording sessions often pack in multiple, similar takes one after another. Evaluating 15 five-minute long traffic tracks can test even the most passionate field recordist. The repetitive nature of mastering can be tedious.
  • Time-consuming. Mastering sound effects involves listening to a single take in passes or waves. A mastering technician needs to trim slates, drop markers, cut away flaws, add fades, process with EQ, name, and more, all in sequence. A file can take as much as ten times its original length to bring it to completion. That’s not hard with a single whoosh, of course. Now, imagine mastering 50 of them, or five hours of raw birdsong ambiences. Tackling these field recordings can be exhausting.

Of course, those challenges are all part of the job of finalizing field recordings. And even that’s not too hard if you have a half hour of recordings. It can, however, be incredibly daunting if you have 100 hours field recordings. All of those issues are compounded with large amounts of files.

What can be done?

Before Mastering: Field Recording

Now, it is possible you’re currently staring at a folder filled with 200 raw field recordings with a faint feeling of despair. We’ll learn how to deal with that in a moment.

Are you just about to head out and record a huge amount of field recordings? These tips can help make your future mastering sessions go more smoothly:

  • Prep file names. It’s common to eagerly rush out the door and begin capturing field recordings immediately. Take a few moments to pre-set file names in your recorder. I now create all my city names into my 722 recorder before I travel: Bali, Chiang Mai, Bangkok, Koh Samui, Kuala Lumpur, and more.
    Now, you may think it’s a simple matter to dial in a file name just before you punch in. That’s true. However, field recording often requires responding quickly to a sound on location. As minimal as the time requirements are to create a file name, it may be lost in the moment.
    I remember arriving in Singapore from Thailand and realizing that the airport lounge I was passing through was filled with the perfect crowd chatter without music or HVAC. I rushed to recorded one golden track after another before they escaped. However, in my haste they were all captured with the "Thailand" naming scheme. Fixing this afterwards isn’t a big deal, but it’s an extra step you can avoid. Set your names beforehand. Switch to them quickly to help identify raw recordings and speed along the mastering process, later.
  • Recorder organization. Some recorders save sound fx in discrete folders. This is another way to organize your clips before you plant yourself in the studio. My file names identified the cities. The folders divided the tracks by country. Other examples include separating tracks for interior/exterior vehicle recording, microphone types, perspectives, and more.
  • Slating. I wrote about slating earlier on the blog. Slating is absolutely essential to help accelerate the mastering process. I have travel tracks on my hard drive recorded over a year ago. It’s challenging to remember the minute, evocative details observed at the time. This is amplified when there is a huge amount of clips to wade through. Just the same, these are the details that will make the final clips speak strongly to listeners, later. Verbally slate each clip to make mastering easier afterwards.
  • Images. Mobile phone photos are a great tool to help supplement slates to recall details of earlier field recordings.
  • GPS. I use the smartphone app MyPlaces! to slate takes, capture photos, and embed GPS into field recording notes. Read about using MyPlaces! to slate sound fx, and other app options. Like images, this info can recall detail to help simplify mastering decisions.
  • Time Stamp. Does your recorder prefix a time stamp to your file name? Enable this. This will help you sort takes later. This is especially helpful if a challenging location doesn't allow slating. The time stamp can help GPS, photos, sent emails, or even receipts become reference points to puzzle out mysterious takes that have faded from memory.

The general idea is to front-load your work by adding detail, reducing analysis, and helping recall memory.

Three Tools to Help Master Bulk Field Recordings

Those are all quick, simple steps that can help mastering later. However, it’s not always possible to accommodate for those steps on location. Perhaps you simply forgot them in the excitement of capturing cool clips. What can you do if those tips slipped your mind when you recorded your raw sound effects?

Use these three primary concepts for helping master large amounts of sound effects in the studio:

  1. Batching.
  2. Organization.
  3. Incremental work.

Let’s take a look.

1. Batching

Batching is the process of grouping similar tasks together. It approaches mastering by completing each partial editing step for every sound at once, instead of completing all total mastering steps for each sound one after another.

For example, it’s best to remove the slates for all 50 clips in your session, one after another. Contrast that to removing the slate, editing, processing, and bouncing the first file, then repeating this sequence for the second, third, and so on. How does this help you?

  • Increased efficiency. Performing similar tasks across all files means you’ll become quicker completing similar actions. It’s easy to apply fades to all similar files, one after another. Your muscle memory will apply the keystrokes quickly. Your ears will evaluate similar fade slopes more easily. Otherwise, you may be referencing fades on work you completed a half hour ago, as opposed to mere seconds, previously. When applied across all field recordings, this invests less time over the scope of the entire session.
  • Less mental energy. This idea adopts the concept behind assembly line efficiency. For mastering, batching consumes less mental effort. The first time puzzling out an EQ notch may take some effort. Applying a notch to similar files afterwards requires even less effort and will be far easier, even if the notch needs slight modification. Some mastering steps performed across all files become so habitual that completing them will be second nature and require little mental energy at all.
  • Comparative power. Performing identical mastering steps at once helps spots differences amongst similar files. For instance, consider the step of applying names to field recordings. The first industrial ambience may take some creativity to write. Does it have a buzz or a hum? Is that a whine or a hiss? After the first is complete, the name for the second, similar track will be easy to write. You’ll notice the next file is like the first, but perhaps adds a deep rumble. That’s easy to tack onto the previous file name. Compare this to switching between naming industrial ambiences and birdsong.

2. Organization

Organization is a way of helping batching. It gathers your field recordings to help take advantage of batching tasks.

For instance, you may group your field recordings by

  • Microphone type.
  • The recording location.
  • Microphone perspective.
  • Date recorded/timeline.

…and so on.

The idea here is that cutting field recordings for one microphone will be related, and allow you to batch similar work for them. Let’s say you’re recording with five microphones. One of them managed to pick up a 13 kHz whine. If you group them together, it will be easier to dial out that whine for all similar perspectives as opposed to switching between field recordings that have the problem and those that do not.

There isn’t a single, particular rule to organizing your tracks. It depends on the type of sounds you recorded. In some instances, it’s best to organize your field recordings by the time you recorded them. That may help you recall how a dawn chorus ambience evolved over time. In other situations, it’s better to group them by perspective: traffic tracks recorded from a catwalk high above the street will differ from those recorded at the curb. By organizing them separately, it will help dealing with peaks and level changes in series.

How can you group similar tracks? Well, the simplest method is to group all similar tracks in their own session. Put all your jungle river recordings in your first session. Save the howler monkeys for a second session.

If the type of sound effects share a closer relation, it’s better to group them in a single session, divided by track. For example, let’s say you recorded ocean waves in a mix of mid-side recordings and conventional stereo tracks. Drop your stereo recordings in the first pair of tracks. Add your M/S recordings in the second stereo pair and apply a M/S decoding plug-in inserted into that track. That way, you’ll be able to compare the similar stereo and M/S files for naming purposes, but cut the M/S and stereo tracks separately in their own tracks.

Another bonus organizational tip: avoid loading your sessions with hours of material. There’s nothing more debilitating than opening a session and seeing hours of unfinished clips ahead of you. Instead, divide your mastering sessions in more rewarding, accomplishable chunks. That helps you feel productive, inspired, and do superior mastering work.

Note: I will explore how to tackle mastering long field recordings in next week's post.

3. Incremental Work

Mastering field recordings from raw source files to final, polished clips demands a lot of time. Each step requires diligence and concentration. Moving through each of these steps can be exhausting. So, it’s often best to complete one or two steps, take a break, then move to the next.

This helps in a few ways. First, it helps deal with listening fatigue. Working all day mastering subsonic rumbles can exhaust your ears, making it harder to hear details. Mastering can be physically exhausting. Also, the detailed, focused work can quickly become repetitive and boring. Finally, spreading out mastering work and returning to the task after a break can bring a fresh ear to the task and help spot mastering errors missed previously.

So, consider mastering incrementally. For example, set aside a day just for naming the sounds. Yes, that may only take an hour or two. That’s fine. Move onto other, unrelated pro sound work. Then, the next day, start bouncing your tracks.

What’s the best way to divide mastering tasks into incremental steps? Earlier I wrote An Introduction to Sound Effects Mastering. The process I use is based on that, with slight variations I've adopted since then. Here are suggestions for dividing your mastering work.

  • iZotope RX first look. Remove small errors in RX. Focus on minute problems that you are comfortable committing to the master file (and always have a backup of the masters, too!). Common tasks are performing minor spectral repair, removing a few clicks or pops, and de-clipping. For instance, a city ambience may have pure traffic except for a single, prominent bird chirp partway through. Open the clip in RX, remove the bird chirp with spectral repair, then commit the changes.
    The idea is that these small changes will allow later, global mastering steps to proceed more quickly. So, avoid more substantial de-noising or EQ’ing until after detailed editing is complete. (See below.)
  • Trim slates and drop markers. These quick, note-taking steps can be performed easily and quickly across all your tracks. Trim your slates from the beginning and end of your files, and drop the info into timeline markers. This prepares your tracks for simpler editing later. The markers give visual cues to the tracks you are editing, and ensure the notes are not lost from trimming. Finally, doing this step in one day provides context for all recordings. That will settle on you overnight and give you a proper sense of scope when editing in detail, later.
  • Editing. This a focused, elaborate step that is best reserved for its own day (or perhaps 2-3 days). It’s one of the most time-intensive tasks. Avoid mixing this with other tasks. If you like, you can drop head and tail fades during this task. I often leave fades to their own day, however.
  • Write names. Even the best field recordings are useless if they cannot be found. This is why writing excellent, evocative names is essential. Reserve a single day for researching details about your subject, then composing consistent names with evocative keywords. Commit the names to the regions edited so far. Read earlier articles about naming sound effects (post 1, post 2).
  • Bouncing. Bounce work completed to date into a new file within the session. Listen to the track as you do it. Keep an ear open for errors missed during previous steps. In-session bounced files commits your work within the context of editing done so far. It also allows you to roll back to previous editing if you spot errors, later.
  • Processing. Processing can be safely applied after a temp bounce file is completed. You may wish to save a separate day for each global processing step: equalization, compression, de-noising, spectral repair, de-clicking, and so on.
  • Write metadata. This usually falls in the category of curation instead of mastering. This is a more detailed spin on writing sound file names. After all, comprehensive metadata requires multiple fields beyond a simple, single file name. Take a day to complete as many metadata fields as you can. Read an earlier article about which metadata fields you should choose.

Of course, these are examples of how to tackle sound fx mastering with incremental work. Is saving each processing step for its own day too liberal? That’s up to you. However you prefer to divide your tasks, incremental work is one of the best ways to tackle the prolonged steps of sound library mastering.

The Art of Mastering Sound FX

Field recordists begin every session attempting to pull an inspiring sound from an environment. Challenges in the field often mean that these clips need polishing before they’re complete. It’s easy to get bogged down in the effort of mastering sound effects. After all, there are dozens of steps needed to clean each file and let the exciting audio that first inspired you sing for your listeners.

That doesn’t mean mastering has to be unpleasant. It doesn’t mean that hordes of files will be overwhelming. Prepare by recording the tracks properly in the field. When mastering, use the tricks of batching, organization, and incremental work to bite off and consume the complex craft of sound fx mastering.

And in the end? You’ll find that the mastering stage transforms from a debilitating grind to an inspiring art. The result? Compelling, evocative sound clips that share the inspiration you felt on location with every listener that hears your tracks.

My thanks to MP for the suggestion for this article.

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