Video summary

Audio Post 202: Pro Tools and Soundly Sound Effects Editing - Background Ambience

Main summary

Key takeaways

Technology

Main topic

An “Audio Post 202” live class focused on Pro Tools background/ambience editing for a short film. The goal was to build a world behind dialogue using layered sound effects, accurate scene transitions, and practical mixing considerations—especially keeping edited ambience consistent with production sound (dialogue glue, masking, and continuity).

Key workflow + technical concepts (background/ambience editing)

Purpose of backgrounds/ambience

Backgrounds/ambience (“room tone,” “ambience,” “backgrounds”) are sound effects around characters that happen in the location.

They serve world-building and practical functions:

  • Glue dialogue to picture
  • Mask inconsistencies in production-recorded dialogue
  • Ensure the background supports what production sound already contains—so the edit doesn’t sound detached

Start by listening to natural layers

Dialogue is kept audible during setup to preserve/understand what’s already in production sound, then backgrounds are built around it.

Stereo monitoring, 5.1 delivery

  • The intended delivery is 5.1
  • For streaming/monitoring, they work in Stereo
  • During editing they use both headphones for stereo monitoring

Session organization in Pro Tools (track strategy)

Checkerboard approach (A/B backgrounds)

They arrange backgrounds in an A/B pattern across scene transitions:

  • When moving between transitions, the editor can quickly duck/adjust one set while the other comes in
  • This supports later mixing with scene-to-scene A/B riding

Track count / layer approach

They initially create many tracks (example given: multiple mono A tracks and stereo B tracks, plus a second set for B).

Rationale:

  • Start with a “blank canvas” pallet
  • Delete unused tracks later

Routing requirement

Everything is routed to the two-bus (explicitly mentioned during track creation).

Scene markers / region groups for frame accuracy

Frame-accurate transitions are emphasized as essential for tight action sequences.

They mark transitions using:

  • Scene 1 / Scene 2 markers
  • Region group creation (option/command G)
  • Markers for crossfades (e.g., “CF”)

Navigation/marker workflow helps keep everything aligned to the edit.

Editing techniques emphasized

Hard cuts vs crossfades

  • Hard cuts: a two-frame crossfade approach is recommended to avoid clicks from poorly matched fades.
  • Action/scene transitions: cut points must align tightly, with crossfades placed around the cut using specified frame offsets.

Crossfade length and frame-rate note

  • Fades are referenced at about 82 ms ≈ two frames at 23.976 fps
  • They confirm tolerance by zooming in
  • Batch fade tools are used, with “option click” mentioned for standardization

Clip Gain instead of fader-first leveling

Rather than riding faders early, they mostly leave faders at zero and manage background levels using clip gain.

Reuse vs repetition warning

They reuse sounds to maintain consistency, but warn against leaving the same full loop visible across shots—repetition can become noticeable.

Better approach:

  • Use cut fragments
  • Place by frame/marker

Sound design with Soundly (sound effects sourcing)

Soundly is used heavily as a sound search + playback tool integrated with Pro Tools (press S to send to Pro Tools).

They like Soundly for:

  • Simplicity
  • Frequent updates and new features (including Voice Designer—text-to-voice reading)
  • A built-in Cloud Library
  • Searching FreeSound.org (noted as CC0, with the claim that credit isn’t required and commercial use is allowed)

They previously used Soundminer / Soundly alternatives, but prefer Soundly for reliability and ease.

Mono vs stereo decisions (background ambiences + SFX)

Reasoning for mono backgrounds

If dialogue is mono, mono SFX help them fit more naturally.

Stereo-only layers can:

  • “stick out”
  • be harder to pan convincingly

Reasoning for stereo layers

Stereo can add more convincing spatial cues—especially when buried under music/dialogue.

Notes from the class:

  • Stereo placement is acceptable for off-screen bird calls if the spatial information sounds natural
  • Stereo → mono is described as easier than mono → stereo

Guideline mentioned

  • Interiors often need less layering
  • Suggested minimum example:
    • quiet intimate dialogue: 1 mono + 1 stereo
  • For intense scenes, use more layers (example: keeping large pallets like 12+12 tracks for a wood/creeping sequence)

Content examples added to backgrounds

Across the short film, they added/edited:

  • Wind beds
    • quiet/gentle, whipper/strong, and sometimes pitch shaping
  • Birds
    • forest birds, lake birds, crows, geese, etc.
    • note: directors often request less birds
  • Water elements
    • lake lapping, water slosh, stream/creek, waterfall rumbles
  • Distant traffic / cars passing
    • car sounds are positioned so the peak aligns with vehicle center in frame
    • Doppler timing: shift pitch so it changes after passing center
  • Aerial/ambient items
    • e.g., a “propeller plane” used as background texture
    • later also mention geese recorded for another film
  • Perspective cuts
    • some tracks remain static for the same location
    • others shift when camera perspective changes

Processing approach discussed (EQ/filtering)

Low-pass / high-pass filtering

Backgrounds are often corrected to match production-sound tonal balance:

  • Low-pass around ~5–8 kHz (gentle slope)
  • High-pass to remove rumble (example: ~100 Hz)

They use EQ mainly as troubleshooting, not always as a creative requirement.

Less tonal fuss if music is present

When music carries the moment, backgrounds can stay simpler to avoid distracting tonal details.

Mixing principles (how they think about final level relationships)

Mix by ear, not numbers

  • Dialogue is kept balanced enough so backgrounds can be raised/lowered around it.
  • Backgrounds may be pulled up “hot” in editing to preview detail.
  • Later they’re ducked under dialogue/music.

They emphasize:

  • Many scenes handle background relationships through clip gain + VCA/bus control
  • Avoid heavy reliance on automation for every move

Tooling / organization concepts explained at the end

Routing folder vs VCA

  • VCA controls group track volume before the bus
  • Routing folder behaves like sub-bus gain and can interact with limiter behavior differently
  • A caution is noted around these differences

Checkerboarding benefits

Makes it easier to perform mixing moves between A and B:

  • scene ducks
  • cross-scene consistency

Batch fades and standardization

Batch fades are used to keep crossfades consistent.

Review / tutorial framing / class structure

  • Described as a short class (starting late due to technical issues).
  • It builds on a previous class about dialogue editing.
  • This session focuses on the “fun part”: sound effects + ambience/background world-building.

Planned next steps for future streams:

  • Next Tuesday: sound effects (vehicles, fight/gun)
  • Possibly foley
  • Then mix in a later session

Contest / community feature mentioned

After the workflow/live collaboration, they planned a mix contest:

  • Viewers upload their stereo mix (5.1 may be mentioned, but described as difficult for streaming)
  • Audience votes (blind voting mentioned)
  • Cash prize discussed

Main speakers / sources

  • Speaker: The instructor/host (unnamed in subtitles), working in Pro Tools and using Soundly
  • Tools / sources cited: Pro Tools, Soundly (including FreeSound.org integration / CC0 cloud library), and comparisons to Soundminer / Soundminer-like DSP tools

Original video