Sound
Viewers will forgive a so-so picture, but not bad sound. If the voice sounds distant, echoey or noisy, people click away within seconds. The good news: recording good sound is cheaper than getting a good picture.
Why the camera's built-in mic won't cut it
The built-in microphone is far from the person speaking, close to lens noise and your hands, and it picks up the whole room equally. Rule number one of sound is: get the microphone as close to the mouth as possible, without it showing or getting in the way.
Types of microphone
| Type | How it picks up sound | Ideal for | Watch out for |
|---|---|---|---|
| Lavalier (lapel mic) | Clipped to the chest, about 8 inches (20 cm) from the mouth | Interviews, vlogs, video podcasts, news reports | Clothing rustle; hide the cable well |
| Shotgun | Very directional, wherever it's pointed | Fiction, on top of the camera or on a boom pole out of shot | In echoey rooms it picks up reflections; get it as close as you can |
| Studio condenser | Very sensitive and detailed | Narration, voice-over, podcasts in a treated room | It picks up all the noise in the room |
| Dynamic | Not very sensitive, rejects room sound | Podcasts in untreated rooms, loud voices | You have to speak into it from very close |
| Compact wireless | A lavalier with a transmitter and receiver | An all-rounder for creators | Battery and interference; many also record internally |
Many current wireless mics record internally as well as sending the signal. Turn it on. If the transmission fails, you have clean audio on the transmitter itself.
Levels: not too low, not clipping
In digital audio, level is measured in dBFS and the absolute maximum is 0 dBFS. If the signal reaches it, it clips (clipping): the waveform gets cut off and you hear a crackle or distortion that can't be repaired.
- Have the person speak in their normal voice, and also laugh or shout if that's going to happen, and set the gain.
- Aim for peaks between −12 and −6 dBFS, with the average voice level around −18/−20.
- Turn off automatic gain control (AGC) if you can: it raises the noise during pauses.
- If your gear allows it, record in 32-bit float: it practically never clips and you can adjust the level afterward.
The meter tells you whether the level is right, but not whether there's a hum, a rustle or the fridge in the background. Always monitor on closed-back headphones. It's the only way to hear what's really being recorded.
The enemy: the room
An empty room with bare walls produces reverb: the voice bounces around and sounds like it was recorded in a bathroom. No microphone fixes it completely, and it's hard to remove in the edit. Solutions:
- Record in rooms with furniture, rugs, curtains, sofas or full bookshelves.
- Hang blankets or comforters out of shot, especially behind the microphone and facing the speaker.
- Move the microphone closer: the closer it is, the more direct voice and the less room.
- For narration, a closet full of clothes makes a surprisingly good vocal booth.
Noise: track it down before you record
Before you hit record, close your eyes and listen for ten seconds: fridge, air conditioning, traffic, a clock, a computer… Turn off whatever you can. And if you can't, at least make sure it's constant: a continuous noise is much easier to clean up than an intermittent one.
When you finish, ask for silence and record 30 seconds of the room's ambient sound (room tone). You'll use it to fill gaps when editing and to let the noise reducer learn what it needs to remove.
Wind and outdoor shoots
Outdoors, wind hits the diaphragm and causes low rumbles. Always use a furry windscreen (a windjammer or dead cat) on the microphone. With lavaliers, place the mic under clothing with a small windscreen.
Separate audio and syncing
If you record audio on a separate recorder, record camera sound too (as a reference) and give a clear clap at the start of each take. When editing, sync by the waveform; most editing programs do it automatically. You'll see this in practice in interviews and podcasts.
- Microphone close to the mouth: that's rule number one.
- Peaks between −12 and −6 dBFS; never at 0.
- Headphones, always.
- Choose furnished rooms, turn off noise and record 30 seconds of room tone.
Your turn: four mics, one sentence
Record the same sentence four ways: with the camera mic from 6 feet (2 m) away, with your phone mic from about 8 inches (20 cm), with a lavalier (or your phone in your shirt pocket) and inside a closet full of clothes.
- Listen to them in order on headphones.
- Write down what you notice in each one: echo, noise, presence.
- From now on, decide what your minimum setup is.
Frequently asked questions
What microphone should I buy to start making videos?
For most videos of people talking, a wireless lavalier mic is the most versatile option. For fiction, or shots where a microphone can't be seen, a shotgun mic as close as possible.
How do I remove echo from a video?
It's very hard to remove completely afterward. There are de-reverb tools, but what really works is avoiding it: move the microphone closer and record in rooms with furniture, rugs or blankets.