Editor’s note: Welcome to “Ask the Engineer,” an occasional series of technical advice columns from Rob Byers, sound engineer, loudness advocate, and the interim director of broadcast and media operations with “Marketplace” at American Public Media. This time, Rob shares a list of questions that smart producers ask before they deliver their tape.
When you deliver audio to a show (or a producer, podcast, new editor, etc.), it helps to arm yourself with a few technical questions to ensure a successful handoff. Unless you’ve worked with a show many times, you might not be aware of the tech and production details that the show prefers. Even if you have worked with a show many times, asking these questions tells your colleagues that you are invested in providing them with what they need:
1. Who lays up the piece and/or mixes?
Ask early in the editing process. It could be that the show or podcast wants to do this themselves so that it fits the sonic style of the show. If that’s the case, some follow-up questions will ensure that you give the producers or engineers exactly what they need to make the best radio out of your audio:
- What program will they use? Perhaps you both use the same audio editor, in which case you can simply share your sessions back and forth.
- If they don’t use the same program, how will they ensure the audio is laid up correctly? Obviously you can share a script and have them do the heft of the work, but if you are going to lay up some of the piece (perhaps you are doing a draft for someone else to tweak), you need a way to share the un-mixed audio so that it syncs nicely on the other end. The most common way to do this is to deliver “stems” — mixed-down versions of separate tracks, usually one for narration, a couple for actualities, and one or two for ambience.
- If you use stems, ask how the person on the other end will know that the audio is in sync. Should they simply line up the files so they all start at the same time? Will you put a small segment of the same audio at the beginning of each stem? This is usually a very simple process, but be sure you understand what they will do, and what they need from you.
2. What format do you want?
There are a wide range of options. Some engineers/producers will be pretty easygoing about these choices, because they are comfortable converting between formats or because their audio editor can handle a wide range of formats. Others will be very particular about this, sometimes for technical reasons, sometimes because of quality concerns.
(You don’t have to share an engineer’s knowledge of why each of these formats is used; you just need to make sure you’re matching the audio specs that the engineer or producer needs. On most recorders and audio editors, these are probably the default settings.)
The most common formats in public radio and podcasting are:
- sample rate: 44.1kHz, 48kHz
- bit depth: 16-bit or 24-bit
- file type: WAV, AIFF, MP2, MP3, AAC, FLAC
- stereo or mono
We’re talking audio specs here, but you might also ask the same question when delivering scripts. Ask your editor if she wants to work with Google Docs and use the handy editing tools, prefers to hand Word docs back and forth, or perhaps likes plain text in an email.
Ask the question ahead of time and save your colleagues frustration!
3. What level spec do you want?
This is a very important question to ask, especially if you are going to mix the piece yourself.
A “level spec” defines the digital level at which your content is mixed. Often it’s defined in terms of a target level – a number at which the average levels in the mix should consistently be near. Level specs in public radio and podcasting can vary from show-to-show, and you want your levels consistent with the other content on the show, which is why it’s important to ask this question.
Hopefully the show or podcast you are working for is using a loudness standard by now. If they are, like many public radio programs these days, then you have an easy spec to interpret. If not, be sure to shame them silly and tell them to get with the times! (I kid … kind of.) If you aren’t familiar with loudness yet, don’t panic; just do your homework. Loudness will help make your productions more consistent.
If they talk to you in terms of peak levels, or “dBFS,” don’t worry. You just need to ask more questions.
- Are you using loudness meters or peak meters? What’s is the average level I should mix to?
- If they mix for loudness, your job is easy. Simply mix to the provided number (something like -24 LUFS) on the Short Term loudness meter. Transom has a good primer about how to handle this.
- If they use peak meters, ask where the voices should sit. You might be told a single number, like “mix your audio to around -15 dBFS,” but that’s hard to interpret. It’s hard to know if that means your mix should constantly hit -15 dBFS, just tickle it, or constantly go through it. If you need more clarification, it’s best to ask the range in which you should mix the voices. You want an answer like “between -15 and -10 dBFS.”
- What is the maximum peak level I’m allowed to hit?
- For what reason — if at all — should I hit the maximum peak level? It might be that a quick laugh, hand clap, or sound effect is a good reason to hit it. Or it could be that, in a typical public radio piece, you don’t have much reason to hit it at all.
4. What happens to the audio after I deliver it?
Even if you mix the audio, another producer or engineer might do some quality control and make slight tweaks to the audio file. That’s a good thing — it means that there is another check in place before the mix makes it to air, and another set of ears to catch mistakes or problems.
But it may be that they’ll take your file and prepare it for a podcast by processing it in some way, or they might convert your stereo file to mono, or may turn it into an mp3 for on-demand listening, etc. It may be helpful for you to be aware of these processes, and you could prevent problems later on in the workflow if you are aware of them. If there is another process further down the line, you can ask:
- Is there anything I can do to make that process cleaner?
- Are there ways of prepping my audio that would make your job easier (or harder)?
5. What “extra” help can I give for production?
There are a few audio-related production details that can really help a producer or engineer. If you want the gold star, consider asking:
- Should I provide extra ambience at the top or tail of the piece if it’s warranted? (This gives the show something to transition in and out of your piece from the studio.)
- Should I provide music or suggest tracks that might fit my piece?
- If there is music at the end of the piece should I provide extra for transitions?
- Should I provide additional ambience in a separate file?
And my favorite question:
6. What’s a piece of audio that best represents the sound of your show?
I’m a big fan of this question. It shows, right out of the gate, that you care about matching the style of the show. This question can provide you with so much useful information: pacing, use of ambience, editorial angle, use of compression and equalization, tone.
It’s a question that just might surprise your colleagues.
Now, one final question: Which questions do you ask?
Rob Byers (@RobByers1 on Twitter) is the interim director of broadcast and media operations with “Marketplace” at American Public Media, an NPR “alum,” a classically trained percussionist, a jazz enthusiast, and a member of AIR’s network. Over the years, he has been lucky enough to engineer recordings with Yo-Yo Ma, Rufus Wainwright, The Knights, Béla Fleck, Joshua Redman, Josh Ritter, Yo La Tengo, Cyrus Chestnut, and many others. He gave a recent, terrific webinar about audio levels, and he thinks everyone needs to know about #loudness.
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