Tips & Tutorials | February 3, 2016
If you’re producing a podcast of your own, you’re likely a writer, journalist, or subject matter expert with great ideas and stories but working with a small budget. Poor audio quality can detract from the message that you’re trying to deliver, so it’s important to get great-sounding, compelling audio.
With a few simple steps, you can vastly improve the sound quality of your podcast—without buying any new equipment or software. Here are 10 podcast audio production tips to help get you the best possible sound.
Whenever you start recording with a microphone while reading from a script or capturing an interview, think about things in your environment that might make noise. Is there a fan on your computer? Can you hear mouse clicks as you scroll through your script? What about page turns? Refrigerators? Cell phones? Cats? Dogs? Birds?
Use headphones to monitor your recording. Turn them up to listen to what the microphone is hearing before you start your delivery or interview. Try to minimize any extra noise as much as possible. A cleaner recording will be easier to handle later on in the process.
It’s also important to think about the acoustics of the space you’re in. Hard, flat surfaces reflect sound like a mirror reflects light. Leave space around you and your microphone to minimize early reflections. Set up on a carpet, near some bookcases, and away from walls. Also avoid reverberant spaces. Some offices, classrooms, conference rooms, and huddle spaces can be especially reverberant. Reverb is hard to remove after the fact (the De-reverb module in RX 6 Advanced makes it much easier), but easy to add later on if you need it for some particular effect.
Plosives, the burst of air that exits the mouth when we make “P” and “B” sounds, are like giant gusts of wind to a microphone. To help mitigate these, avoid talking directly into the front of the microphone and use a windscreen or pop filter when possible. Set your microphone up slightly to the side so those bursts of air don’t go directly into the diaphragm.
Don’t set it up at too extreme of an angle, though, or you’ll be talking into a null in the pickup pattern of directional microphones. You should notice a much more natural sound for your voice. Experiment with your microphone placement and capture test recordings to find what sounds best for your voice.
Many broadcasters and voiceover artists stand when recording to help provide better air support and a strong, confident read. This can also help mitigate early reflections caused by a desk. If you do need something to hold your script, a music stand works well. Consider placing a piece of foam or a carpet sample on the music stand behind your script, to avoid early reflections.
Most audio interfaces and recorders need you to set an input level for your microphone. Since the advent of high-quality digital recording, there’s really no reason to set input levels too “hot.” You can always make things louder later on.
To set a good, modest input level, speak at a normal-to-loud speaking voice and aim to make this level around -20 dB, or about halfway up on most meters. Then test with a hearty laugh or emphatic phrase to make sure the level never peaks above 0 dBFS or goes “into the red.” If you’re worried that it might, just turn it down and be conservative.
Compression artifacts compound over time, so make your initial recording with a high-quality WAV or AIFF file. However, there’s really no need record a file at any resolution higher than 24 bit, 48 kHz. With high-quality source material, even if your recording goes through a data compression codec (like MP3 or AAC) for distribution, it will be starting from the best possible source material.
Before recording an entire podcast, make a test recording first. Or listen back to a previous recording and compare it to other podcasts that you enjoy. Listen to your test in the environment you expect your listeners to be in, like a bus, subway, or car, and on multiple listening devices, from earbuds to high-fidelity headphones. Take some notes on what you might improve. Does your read trail off at the end of phrases? Is there a lot of background noise or mouth noise that you might want to remove?
You can also use this test recording to get feedback from trusted colleagues, both on the content and sound quality. You might even send it to one of your favorite podcast hosts and see if they’ll give you some feedback (and perhaps a mention in one of their podcasts or social media channels!).
No matter how nice your microphone is, there is no substitute for a confident read and great content. There are only a few professionals with the innate ability to do it live. Editing a script is much easier than editing audio, and gives you the advantage of having all your great ideas laid out in a text format that could be used for something else, like a transcript (extra credit for timestamps), blog post, or even a book down the road.
Obviously, you can’t script interview segments and co-host interaction. But having a solid outline with your introductions, questions, transitions, and closings prepared can help make for a smooth podcast, and show your guests that you’ve done your homework and are prepared and professional.
It can also be helpful to give your listeners an outline of what you’ll be talking about up front, and a summary of takeaways at the end. This can set the context for your episode and wrap it up nicely—a great idea for presentations and pitch meetings, too!
When working with guests and co-hosts who can’t be in your studio, you can turn to VoIP services, like Skype or Google Hangouts, or the telephone. The audio quality is not always the greatest, but it’s easy to record great audio in both locations and then merge them together later. Just ask your remote guest to record a high-quality WAV/AIFF file of only their voice that they can send to you later.
If they don’t have a microphone and podcast setup themselves, just making a local recording with their computer microphone or into an app on their mobile device can provide superior sound quality to what you would get through VoIP or telephone. Conduct your two-way communications for the interview recording through the traditional channel, but then get their recorded audio after the fact and combine it with your recorded audio.
When scheduling your podcast for recording and deployment, be sure to leave time for a careful edit and QC (quality control) of your entire piece. The listener’s time is precious, so make your message clear, concise, and professional. Limit dead air, remove duplicated topics, and fix the occasional “um,” “ah”, and false starts.
Editing can be overdone, however, so challenge yourself to get the best possible read in one segment. You don’t want to edit the audio to death, but brevity is always appreciated by listeners!
Here are some tools built right into your DAW (digital audio workstation) or audio editing software that can help mitigate some problems in your audio and create a great-sounding podcast for your listeners:
A high-pass filter only allows sounds above a certain frequency to pass through. Everything else is filtered out. Because most speaking voices don’t generate any fundamental frequencies below about 85 Hz, you can set a high-pass filter around 80-100 Hz to help remove rumble and plosives that your listeners won’t want to hear anyway.
A bit of equalization can help compensate for resonances in your room, or certain frequencies that might seem to stick out when you hear your voice through your microphone. It’s generally best to cut frequencies rather than boost them. Be aware of using extreme boosts or cuts of more than 6 dB. They may sound good on your headphones or speakers, but may be too extreme on a different set of headphones.
Compression takes louder sounds and turns them down slightly whenever they happen, to even out the differences between loud and quiet words or sections. After compressing these louder sounds, you can turn up the overall sound of your voice, making everything seem louder overall. This can be helpful when people are listening to your podcast in noisy situations like a subway, car, or bus. This is another effect that shouldn’t be used to extremes. Start with a ratio of 2:1 and lower the threshold of the compressor until it activates only on the loudest sounds
De-essing is like a blend between compression and equalization. It compresses the sound of your voice but only in the frequency range where very sibilant sounds live (4 kHz to 7 kHz). Many people’s voices exhibit an unpleasant sibilant sound when speaking into a microphone. A subtle de-essing can make your voice easier to listen to for a long period of time. (The De-esser module in Nectar is a great tool for helping reduce unwanted or exaggerated sibilance.) Set the threshold for a de-esser just like you did with the compressor: Lower the threshold of the de-esser so that it only activates on “S” sounds. Be careful not to overuse it, though, or you could lose intelligibility in your voice.
Broad level adjustments can help bring your podcast into a loudness range that is similar to other podcasts. There are two levels that you will want to consider: peak and RMS. Peak level represents the amount of signal before the sound starts to distort. Generally, a peak level of -1.0 dB is good for podcasts and will ensure that your audio sounds good even when it’s converted to a lossy format like MP3 or AAC. RMS level approximates an average level of your signal. An RMS level around -16 to -12 dB should be good, and is similar to the level that services like YouTube and iTunes normalize material to. Use the meter in your DAW to look at these levels and raise the output of your audio until your levels look just right. Broadcasters across the world use loudness measuring tools to deliver their audio to very particular loudness standards.
Here are three well-known podcasts that have great sound quality to complement their outstanding content. Use these as references for your own podcast. Listen to yours next to each of these, and see where you might make some adjustments to get yours to sound just as good.
It makes sense that a podcast about great music would make sound quality a top priority. Notice the natural dynamics and balance among the voices of hosts Bob Boilen, Robin Hilton, and their guests. Originating from NPR’s studios in Washington, D.C., they have the advantage of carefully designed and well-appropriated studios as well as a staff of top-shelf engineers who help engineer their live music recordings and broadcasts from venues all over the world. TechHive author Mark Sullivan gives some good tips for podcasters on equipment you might look at for capturing that “NPR Sound” at home.
Executive coach Tom Henschel and his company Essential Communications just celebrated their tenth year publishing this free podcast of executive coaching tips. In addition to over 30 years of coaching experience, Henschel is a Juilliard-trained actor. He presents his ideas in a thoughtful and engaging way, delivered with all the effortlessness of a professional voice actor.
This podcast, an offshoot of the hugely successful (and great-sounding) This American Life, has garnered record-breaking listenership in its first season. Its cinematic storytelling and engaging content combine with careful production, editing, and mixing with the help of composer and engineer Mark Henry Phillips. Employing skills from forensic audio restoration to composition and sound design, he helped ensure every element of the story is able to be heard by listeners, and reinforced with underscoring and sonic painting that brings extra dimension to the story.
We spoke with some of the best podcasters in the world today and asked them one simple question: as a podcaster, what is your top audio challenge, and how do you address it?
Mixer/composer Mark Henry Phillips' arsenal of audio techniques have helped transform the hugely popular Serial podcast from an auditory-only medium into a multisensory, tactile experience.