Ducking

01 / UNDERSTAND & APPLY

Connect dialogue to the level of the bed

Ducker lowers a selected track when a signal is present in its assigned source. A music bed or background effect under dialogue is a common use. In Resolve 21, one Ducker can respond to multiple tracks, allowing the music to make room for each participant in a conversation.

Blackmagic describes Ducker as a level-changing process without compression or limiting of the incoming signals. It is a dedicated Track FX processor with its own controls. A sidechain-compressor recipe using Threshold and Ratio belongs to another interface.

Assigning Source establishes control of attenuation; it does not move the spoken line onto the music track. Dialogue retains its normal route to the mix. In the teaching example, A1 and A2 contain speech and A3 contains music; Ducker is opened on A3.

Reference: Blackmagic Design — DaVinci Resolve 21 Reference Manual · Fairlight Track FX · Blackmagic Design — Fairlight / Automatic Ducking

02 / UNDERSTAND & APPLY

Assign the target and every dialogue source

1. Select what should get quieter

   In the Fairlight Mixer, locate the music track, for example A3 MUSIC. Check its name and ordinary level. Open Ducker on this track.

2. Expose Track FX

   Enable Track FX in the Mixer three-dot menu. If Ducker is hidden, select it in Visible Track FX. It occupies a fixed dedicated position; this workflow does not require finding it among ordinary Effects inserts.

3. Assign the first source

   In Source, select the first speaker’s track, such as A1 DIALOGUE. Play that person’s line and confirm that the music changes level rather than the speech itself.

4. Add the other speakers

   The manual shows multiple source selection using Command-click. For an explicit list, use the selected target track’s Audio Inspector: press + beside Source 1 to create Source 2, then select A2. Additional sources can be added in the same way.

5. Check speakers separately

   Find a passage with A1 only, then A2 only, then overlapping dialogue. If only the first source is selected, the second speaker’s line does not necessarily duck the music.

6. Recheck after editing

   If speech moves to another track or a new speaker track is added, revisit Source. Use current track names and actual content rather than relying on the original A1/A2 numbers.

Reference: Blackmagic Design — DaVinci Resolve 21 Reference Manual · Fairlight Track FX

03 / UNDERSTAND & APPLY

Five controls for depth, entry and return

The processor window labels the controls Duck Level, Lookahead, Rise Time, Hold and Recovery. The manual text calls Duck Level “Duck Amount” and Recovery “Recovery Time”. These are naming differences between the illustration and description, not extra controls.

The documented defaults are 2.7 dB, 15 ms, 10 ms, 150 ms and 750 ms respectively. They provide a starting point for comparison. Suitable attenuation and recovery depend on the dialogue, music and gaps in the actual passage.

Reference: Blackmagic Design — DaVinci Resolve 21 Reference Manual · Fairlight Track FX

04 / UNDERSTAND & APPLY

Read the envelope alongside the phrase

The native window shows the incoming signal in gray and the action of Ducker in yellow. A downward dip in the yellow line indicates target-track attenuation. Compare the display with the music itself: the same depth can feel different in a busy rhythmic cue and a quiet texture.

Lookahead and Rise Time affect the beginning of the transition. If music masks the first consonant, check the source assignment and line entry first, then compare anticipation and time to reach the selected depth. Increasing Lookahead starts attenuation earlier; increasing Rise Time makes the move to that depth take longer.

Hold and Recovery affect gaps and the end of speech. In a short gap between words, listen for an unnecessary music rise. If the bed remains low for too long after the final line, compare hold and recovery separately. Changing everything together makes the cause difficult to identify.

Reference: Blackmagic Design — DaVinci Resolve 21 Reference Manual · Fairlight Track FX

05 / UNDERSTAND & APPLY

Establish balance before shaping the response

1. Choose a revealing passage

   Use 20–40 seconds with two speakers, a short pause, a longer gap and exposed music. With one speaker, retain the different types of gap.

2. Set levels without ducking

   Disable Ducker and establish a useful speech-to-music balance. Check unusually quiet lines on the dialogue track; deeper ducking does not solve every variation in the voice.

3. Assign and verify Source

   Enable Ducker on the music, select the dialogue tracks and listen to each speaker. Confirm that all intended lines trigger a response before changing timing.

4. Choose the depth

   Compare modest and more obvious attenuation, for example 3 and 6 dB. These are teaching comparison points. Listen to the meaning of the line and the role of the music rather than aiming for silence under every word.

5. Shape the entry

   Compare Lookahead and Rise Time separately on the same initial consonant. Notice when the dip begins and how apparent the transition sounds.

6. Shape the gap and ending

   Compare Hold and Recovery separately on a short gap and after the final line. Keep the movement that fits the scene’s pace.

7. Replay the whole passage

   Listen without stopping, then compare with Ducker itself disabled. Check words, music, overlapping lines and the move into the next scene.

Reference: Blackmagic Design — DaVinci Resolve 21 Reference Manual · Fairlight Track FX · Blackmagic Design — Fairlight / Automatic Ducking

06 / UNDERSTAND & APPLY

Explore sources and five parameters on a diagram

In the teaching example, A1 and A2 are sources with predefined phrases and A3 is the music target. Select A1, A2, both or neither and observe which phrases trigger attenuation. Then change depth, Lookahead, Rise Time, Hold and Recovery one at a time.

The model constructs a simplified level envelope from known phrase boundaries. It explains the direction of parameter changes but does not reproduce the detector or exact native Ducker curve. Its 0–12 dB depth window is not presented as the plugin’s full range. There is no audio playback or analysis of your file.

07 / UNDERSTAND & APPLY

Match the response to the scene

08 / UNDERSTAND & APPLY

Inspect the material controlling the move

Ducker uses the signal from its selected sources. Before a complex adjustment, listen to them alone: confirm that they contain the intended lines and check for sustained unwanted sound, an accidental duplicate or material that should not control the music.

When music reacts at an unexpected moment, begin with Source and the track’s contents. Then check edits around pauses and the dialogue treatment. One noisy source deserves its own investigation instead of compensation through ever greater Hold or Duck Level.

Voice Isolation, Dialogue Leveler and Dialogue Separator may help prepare dialogue, depending on the recording problem. After changing a source, recheck the actual Ducker response. The manual does not supply a universal preset for the complete chain or disclose the detector’s full behaviour here.

Reference: Blackmagic Design — DaVinci Resolve 21 Reference Manual · Fairlight Track FX

09 / UNDERSTAND & APPLY

Combine automatic response with editorial intention

Ducker is useful for repeated responses to spoken lines. Automation is useful when music must rise on a particular beat, remain quiet for a dramatic pause or fade toward the end of a scene regardless of speech.

If both approaches affect one bed, compare the base level, automation and Ducker in turn. Music that feels too quiet may reflect several intentional reductions acting together. Keep a clear starting balance and listen to the result with all intended changes active.

Disable Ducker itself to bypass it; Effects In does not bypass this Track FX. After writing automation, replay the transition without making new control moves and confirm that an unintended value does not carry into the following scene.

Reference: Blackmagic Design — DaVinci Resolve 21 Reference Manual · Fairlight Track FX

10 / UNDERSTAND & APPLY

Trace the problem from what you hear

11 / UNDERSTAND & APPLY

Keep the assignments, timing and actual result

Record the target, the complete source list, all five values and the comparison passage. Identify the line entry, the short gap and where music should return. If automation is present, note what it adds to Ducker’s action.

After changing the track layout and after reopening the project, check every speaker. At delivery, listen to the rendered file at the same passages. An accepted result should retain clear words, musical character and suitable transition timing, not merely movement in a graph.

FAQ / BEFORE THE NEXT MOVE

Questions that matter in practice