Chapter 14 — Key Takeaways

The screenshot-and-re-read card for production audio. Keep it on your phone; glance at it before any shoot with a voice in it. The one idea under all of it: get the right microphone close to the source, aim it, and reject the rest — because a mic can only capture what reaches it.

The definitions, in one line each

Term Definition
Microphone A transducer that converts the sound reaching one point in space into an electrical signal — so where you put it decides the result.
Dialogue The recorded speech of people in your video; usually the most important sound, and the one viewers won't strain for.
Room tone The ambient sound of a location with no one talking (hum, hiss, air); the editor's connective tissue. (Recording it = a habit, owned by Ch.15.)
Lavalier (lav) A tiny clip-on mic worn on the person near the chest; always close, usually omnidirectional.
Shotgun mic A long, narrow, directional mic (interference tube) that hears a tight front zone and rejects the sides.
Boom The pole that holds a mic close and just out of frame — and the technique of using it.
Polar pattern The map of a mic's directional sensitivity — where it hears loudly, where it rejects.
Gain How much the recorder amplifies the weak mic signal; set manually, before recording.

The one principle, and its proof

Principle Why Proof you can run
Placement beats price A mic captures only what reaches it; closeness wins the direct-to-reverberant ratio (voice over room echo/noise). Record one line from across the room, then 6" away — same mic. The close one wins, every time.
Sound is half the picture Audiences forgive a soft image but abandon bad audio in seconds — "wrong" sound trips an alarm below thought. The "sound-off / sound-on" test; the roomy-vs-present A/B.
Quiet the room first The cheapest, biggest upgrade — beats buying a better mic. Record with the fridge/HVAC on, then off. Night and day.

Mic selection — match the tool to the job

Situation Reach for Because Watch out for
Seated interview / testimonial, hide the mic Lav (wired if static) on the person = always close, consistent, invisible clothing rustle, cable thump, off-center dropout
Subject moves / sits far from recorder Wireless lav closeness of a lav, no cable batteries, radio dropouts — buys movement, not better sound
Two-person or scripted scene, mic off-shot Shotgun/supercardioid on a boom directional + close + out of frame needs an operator; mind the frame line & light shadow
Small, reflective, echoey room Supercardioid / hypercardioid rejects reflections without a shotgun's roomy tube small rear lobe — keep noise from directly behind
Reporting, hosting, stage, vox pops Handheld "stick" rugged, at the mouth; visible is expected here occupies a hand; is seen (fine for the genre)
Any shot where the camera must be far Off-camera mic (any of the above) decouples mic from frame — go to the sound on-camera mic is stuck at the camera's distance
Phone, no budget Cheap wired lav or get the phone close proximity does the work; a $5 lav = pro dialogue need a TRRS / USB-C / lightning adapter

Buy exactly one audio thing for this whole book? Buy a lav. Highest-return purchase in video.

Polar patterns — where each mic listens

Pattern Hears Rejects Typical use Note
Omnidirectional all directions equally nothing most lavs fine because it's close; forgives head-turns
Cardioid front + sides the rear many handhelds point the back at the loudest noise
Super / hypercardioid tight front sides (small rear lobe) interior dialogue best small-room mic; watch what's behind it
Shotgun (lobar) narrow front lobe, long reach the sides film, outdoors, boom roomy indoors; directional ≠ telephoto for sound

Off-axis rejection: point the sensitive (on-axis) direction at the mouth; point the deaf (off-axis) zone at the noise. For a directional mic, aim is the recording.

Placement — the three rules

Rule What it means Lav Boom
Close near the mouth (best ratio) 6–8" below the chin (built in) 1–2 ft, as near as the frame allows
On-axis sensitive direction at the source center it on the sternum aim the barrel down at the mouth
Out of frame never seen (unless a handheld) hidden under a layer, cable dressed down just above (or below) the frame line

Two-mic safety: on important dialogue, record a lav and a boom — lav = consistent backup, boom = natural preferred sound. Gives the editor a choice and covers a rustle, a dead battery, or a drifted aim.

Levels cheat sheet (dBFS)

Target Value Why
Dialogue peaks around -12 dBFS loud, clean, headroom to spare
Absolute peak (loudest laugh/shout) below 0 dBFS 0 dBFS = clipping = destroyed forever
Room tone / quiet ~ -40 to -50 dBFS near-silence should read low; if high, the room's too noisy
Set the level using the subject's real, loudest delivery people get louder on "record"; leave headroom for it
Auto gain (AGC) OFF it pumps — raises the noise floor in pauses
Judge quality on headphones the meter shows level, not rustle/hum/echo

The asymmetry to memorize: a little too quiet is recoverable (boost it, pay in some hiss); too loud is not (a clipped peak is gone). When unsure, err low and protect headroom.

  0 dBFS ┤▓▓  ← NEVER hit this (clipping)
  -6     ┤██
  -12    ┤██████  ← dialogue peaks live HERE
  -24    ┤███████
  -45    ┤████████ ← room tone / quiet
  -inf   ┴─────────

On-camera vs off-camera

On-camera Off-camera
Mic sits… at the camera's distance (frame-chosen, usually too far) on the subject (sound-chosen, close)
Sound roomy, distant by default present, clean
Good for arm's-length vlog; a scratch track to sync to everything else — the pro default
On its own recorder = — double-system sound (sync in the edit → Ch.15)

Top common mistakes → fixes

Mistake Fix
Camera on a tripod across the room, built-in mic Get a mic close — lav on the subject or boom off-frame.
Shotgun on the camera, indoors It's far and roomy — boom it close, or use a lav / supercardioid.
"The shotgun will zoom in on sound" It's directional, not telephoto — it still must be close.
Auto gain left on Switch to manual; AGC pumps the noise floor.
Judging by the meter / camera speaker Headphones — the meter shows level, not quality.
Gain too hot → a word clips Set level to the loudest real delivery; keep peaks < 0 dBFS.
Gain too low → boosted hiss in post Aim peaks at -12; don't record tiny and lift it later.
Lav rustle on movement Mount away from fabric; tape a strain-relief cable loop.
Lav dull / drops on head-turn Center it high on the sternum (omni forgives the turn).
Directional mic aimed at the chest/wall Aim the on-axis direction at the mouth.
Forgot the noisy fridge/HVAC Kill room noise first — cheapest upgrade there is.
No room tone recorded Grab 30 seconds — the editor needs it (Ch.15).

Story & craft principles (Part III throughlines)

Principle Here it means
Sound is half the picture Give audio equal weight to picture; the mic is a second "camera" you aim and check.
You shoot for the edit Consistent close placement + room tone = cuts that assemble, not fight.
Fix it in pre, not in post Quiet the room, place the mic right, set the level — post can't add presence or un-clip.
Motivate every choice Choose the mic by the situation (subject, room), not by the spec sheet or price.

Your project increment (Production Checkpoint)

  • Record your Project 1 talking-head with a proper mic — a lav or a boomed shotgun/supercardioid, placed close, on-axis, out of frame.
  • Set gain manually so dialogue peaks near -12 dBFS, peaks below 0; AGC off.
  • Listen on headphones to a test take before the real one — hunt rustle, hum, echo, and fix it at the mic.
  • If you can, record lav + boom at once (two-mic safety; previews Ch.19).
  • Project 1's picture and sound are nearly complete — Ch.15 adds location-sound discipline + room tone and locks it.

The one-sentence version

Get the right mic (lav / shotgun / handheld) close to the mouth, on-axis, and out of frame; set gain so dialogue peaks near -12 dBFS and never clips; judge it on headphones, not the meter — and your video will sound as professional as it looks, which is half the whole game.