Chapter 33 — Key Takeaways
The one-page card to screenshot before an audio-post session. Definitions, the order of operations, the dialogue chain, loudness targets, and the mistakes that sink a mix — mostly tables, by design.
The core idea
Audio post is where "sounds professional" is won — the payoff of sound is half the picture. You do not start until the picture is locked, you build the mix dialogue-first, and you master to a loudness target, not past it. The picture never changes; your command of its sound does.
Definitions (first-defined this chapter)
| Term | Definition |
|---|---|
| Audio post | All the tasks that turn raw timeline sound into a finished soundtrack: organize/sync, clean, level, score, design, and master. |
| The mix | The balanced blend of all sound elements — every level, tone, and placement set so nothing fights and the dialogue is always clear. |
| Dialogue cleanup | Removing everything from the recorded voice that is not the voice — clicks, rumble, hum, hiss, room ring. |
| Noise reduction | The tool that learns a "noise print" (ideally from recorded room tone) and lowers steady background noise while keeping the voice. |
| EQ (equalization) | Raising/lowering specific frequency bands to shape a sound's tone — cut mud, add presence, roll off rumble. |
| Music bed | Music laid under the dialogue and picture to set mood and pace, sitting low and ducking under the voice. |
| Sound effects (SFX) | Added non-musical sounds — ambience beds and synced spot effects — that build a believable space. |
| Loudness | How loud a program feels over time (not its peaks), measured in LUFS. |
| LUFS mastering | Setting the whole mix's overall loudness to a destination target while keeping true peaks under a safe ceiling. |
The order of operations (memorize this)
| # | Step | Do | Rule |
|---|---|---|---|
| 1 | Organize & sync | audio into stems (dialogue/music/SFX/ambience) | separate so you can control each |
| 2 | Dialogue cleanup | de-click → high-pass → de-hum → noise-reduce | reduce, don't resurrect; less is more |
| 3 | EQ & level | cut mud, add presence; compress; ride | cut before boost; peaks ~-12 dBFS |
| 4 | Music bed | choose, license, place, duck | dialogue is the boss; music serves |
| 5 | SFX & ambience | ambience bed + synced spot effects | ambience hides edits; sync to frame |
| 6 | Final mix & master | balance, automate, master to loudness | ~-14 LUFS, true peak ≤ -1 dBFS |
The mix priority order (loudest → quietest)
| Layer | Typical level vs. dialogue | Job |
|---|---|---|
| Dialogue | the reference; peaks ~-12 dBFS | carries meaning — always clear, always on top |
| Spot effects (SFX) | ~-18 dBFS accents | punctuate actions; synced to frame |
| Music bed | -24 to -30 dBFS, ducks under lines | mood and momentum; lifts in gaps |
| Ambience | -28 to -34 dBFS, continuous | establishes place; hides edits |
If any layer ever makes a word harder to understand, it is too loud — no exceptions.
Dialogue cleanup guide (in order, gentlest first)
| Problem | Tool | Setting / note |
|---|---|---|
| Clicks, pops, bumps | de-click / manual dip / cut+patch | do first; patch gaps with room tone |
| Low rumble (traffic, HVAC, handling) | high-pass filter | ~80 Hz; back off if voice thins |
| Tonal electrical buzz | de-hum | notch 50/60 Hz + harmonics |
| Steady hiss / drone | broadband noise reduction | learn print from room tone; ~8-10 dB, then stop |
| Room echo / reverb | de-reverb | can reduce only, never remove — fix on set |
| Harsh "s"/"sh" | de-esser | tame 5-8 kHz only when it spikes |
Over-processing = "underwater," swirly voice. The cure becomes worse than the disease. Do less; mask residue with a slightly louder ambience bed.
Dialogue EQ (subtractive first)
| Region | Move | Why |
|---|---|---|
| ~80 Hz | high-pass | remove sub-bass rumble |
| 200-400 Hz | cut 2-3 dB | clear the "mud"/boom (lavs especially) |
| 500 Hz-1 kHz | small cut | open "boxy," small-room sound |
| 3-5 kHz | boost 2-4 dB | presence — intelligibility, "cut through" |
| ~10 kHz | high-shelf +1-2 dB | "air," polish |
Cut problems before boosting good parts. Toggle the EQ against raw to confirm you improved it. Then compress gently (~2:1-3:1, 3-6 dB) and ride the big swings by hand.
Loudness targets (master to these)
| Destination | Integrated target | Peak ceiling | Note |
|---|---|---|---|
| Streaming / social (YouTube etc.) | ~-14 LUFS | -1 dBFS true peak | the book's Project 3 target; platforms normalize to ~this |
| Podcast / spoken word | ~-16 LUFS | -1 dBFS | mono deliverables common |
| Broadcast — Europe (EBU R128) | -23 LUFS | -1 dBTP | strict, enforced; ±1 LU |
| Broadcast — North America (ATSC A/85) | -24 LKFS | -2 dBTP | LKFS = LUFS under another name |
Treat exact numbers as current-and-revisable — confirm the destination's spec (Chapter 36). The principle is fixed: measure integrated loudness, master to target, never cross the peak ceiling.
dBFS vs LUFS (don't confuse them)
| dBFS | LUFS | |
|---|---|---|
| Measures | instantaneous peak | perceived loudness over time |
| Ceiling / target | 0 dBFS = clipping | destination target (e.g. -14) |
| Used for | leveling dialogue, avoiding clipping | mastering the whole program |
Music: the licensing rule
Use only music you can prove you are licensed to use. Credit is not a license; "not for profit" is not a defense; automated systems block/mute/demonetize infringement.
| Legal source | Cost | Watch for |
|---|---|---|
| Royalty-free / production library | one-time or subscription | keep the license/receipt |
| Creative Commons | free | follow the exact terms (attribution? non-commercial?) |
| Commissioned original | pay a composer | clean ownership |
| Platform-cleared library | free on that platform | may not transfer off-platform |
Full legal treatment — sync rights, releases, copyright — is Chapter 38.
Top mistakes → fixes
| Mistake | Fix |
|---|---|
| Starting audio post before picture lock | lock the cut first; every fix is frame-keyed |
| Music too loud / fighting dialogue | duck the bed; dialogue is the boss; pick a sparser track |
| Unlicensed "temporary" song | license first — never build the mix on it |
| Over-cranked noise reduction ("underwater") | back off to ~8-10 dB; mask with ambience |
| Boosting EQ before cutting | subtractive first |
| Dead silence at cuts ("blinking") | lay a continuous ambience/room-tone bed |
| Spot effects off-sync | place frame-exact; nudge to the action |
| Over-limiting to be "loud" | platforms normalize — master to target |
| Judging only on studio headphones | QC on phone speaker + mono + a car/TV |
Craft principles surfaced
- Sound is half the picture — this chapter is its payoff; the finish decides "professional."
- Fix it in pre, not in post — pointed at your own workflow: lock, then finish sound; and cleanup reduces, it cannot resurrect.
- You shoot for the edit — room tone recorded on set becomes the noise print, the edit patch, and the ambience seed.
- Motivate every choice — every effect, cue, and bed serves the story or comes out.
Pre-flight checklist (run before you export)
| ✓ | Check | Pass if… |
|---|---|---|
| ☐ | Picture locked | no pending edits; every sync still holds |
| ☐ | Dialogue clarity | every word clear on a phone speaker at half volume |
| ☐ | Dialogue level | peaks ~-12 dBFS, steady; no volume-knob moments |
| ☐ | Noise | floor low, no hum; voice not "underwater" |
| ☐ | Music | licensed (receipt kept); ducked under every line |
| ☐ | Ambience | continuous; no cuts "blink" to silence |
| ☐ | Effects | synced frame-exact; below dialogue |
| ☐ | Loudness | integrated ≈ target (-14 streaming) |
| ☐ | True peak | ≤ -1 dBFS |
| ☐ | Mono check | dialogue survives; no effect vanishes |
If any box is unchecked, you are not done — that box is exactly what a viewer will hear and you will not be able to name.
Project increment
Production Checkpoint (Project 3): mix Project 3 — stems; clean and level the dialogue; add a licensed music bed and an ambience bed with synced effects; master to about -14 LUFS, true peak ≤ -1 dBFS; QC on a phone and in mono. Keep the stems (Chapter 36 exports to delivery spec; Chapter 39 folds it into your reel).
Anchor
The Café Scene got its soundscape: cleaned/matched counter dialogue, a looped-room-tone café ambience, the door bell and espresso SFX, a ducked warm music bed — mastered to -14 LUFS. The scene never changed — your command of it did.