Automatic Dialogue Replacement (ADR)

Technical Fundamentals

ADR (Automatic Dialogue Replacement, or in German film jargon "Nachsynchronisierung" or "Dubbing") is a structured post-production process in which actors re-record dialogue in a soundproof studio and synchronize it with the lip movements on the video.

When is ADR Needed?

ADR is used in the following scenarios:

1. Technical Errors (most common reason)

• Aircraft noise impossible to remove
• Loud wind interference
• Radio interference or radio noise in the lavalier
• Permanent background noise (construction site, street)

1. Artistic Reasons

• Actor's performance was weak, director wants to re-do
• Dialogue was changed on set (not yet text-locked)
• Voice characterization changed (tonality, accent)
• Better audibility (original was too quiet)

1. International Versions

• German version for the European market
• English version for US/UK
• Dubbing artists speak a different language

1. Creative Re-recording

• Director wants to rewrite/re-record scene
• Timing adjustment (edit was changed, dialogue no longer fits)

Typical ADR Setup

A professional ADR studio consists of:

1. Soundproof Room ("Voice Booth")

• Acoustically isolated (±40-50 dB isolation)
• Small rooms are optimal (2m x 3m x 2.5m high)
• Not too much reverb (no echo, clean direct sound)

1. Technical Room (adjacent)

• ADR mixing console and recorder
• Video playback system
• Monitoring and communication

1. Video Monitor

• In the voice booth, shows the film scene
• Timing markers ("Beep" 3 seconds before line)
• Typically a 27"-32" monitor for good visibility

1. Headphones and Talkback

• Actor hears video audio and click track (3 beeps before dialogue)
• ADR supervisor speaks via talkback: "Next line..."

1. Microphone and Interface

• Studio condenser microphone (e.g., Neumann U87, Shure KSM9)
• Shock mount and pop filter
• Audio interface (minimal latency)

Level Standards for ADR

ADR is recorded to higher standards than set audio:

Practical ADR Workflow

Phase 1: ADR Preparation (Sound Mixer/Post-Production)

Before actors come in for ADR:

1. Scene Analysis:

• Which lines are unusable? (Sound mixer creates a list)
• Example: Scene 12, Line 5: "I'll come by later" (Aircraft noise)

1. Video Editing:

• ADR supervisor cuts out scenes, marks dialogue start and end
• Note timecode numbers (Start: 00:12:34:10, End: 00:12:36:15)

1. ADR Script Creation:

• List of all lines to be re-recorded with context
• Example:

 ADR LINES - "The Film"

 SCENE 12: Living Room
 Character: Anna (Actor: Maria Klein)

 1. "I'll come by later." [Sad, reflective]
 2. "Okay, see you then." [Quick, impatient]
 3. "Why aren't you talking to me?" [Angry, emotional]

Phase 2: ADR Session (in the Studio)

Pre-Session Meeting (15 minutes):

• ADR supervisor explains the process
• Actor listens to the video once completely (without speaking) – "Reference Pass"
• Discussion about tone and emotion ("This line should have more sadness")

Recording Process:

For each line:

1. Setup: Video cued to the correct spot
2. Countdown: ADR supervisor says: "Next line: 'I'll come by later' – Take 1. In 3... 2... 1..."
3. Beep Track: 3 beeps (click sounds) before the video dialogue starts (allows actor to synchronize)
4. Recording in Progress: Actor speaks while the video plays and shows lip movements
5. Actor Watches Monitor: Tries to match lip movement (lip-sync)
6. After Take Review:

• ADR supervisor checks timing
• Sound mixer checks levels and quality
• Feedback: "Too early – speak later," "Good, Take 2 acceptable"

Typical Number of Takes per Line: 2-5 takes (some lines need 10+)

Phase 3: ADR Quality Control

After the session:

• ADR supervisor reviews all takes
• Selects the best takes (typically 2-3 final versions per line)
• Rough export (WAV file)

Phase 4: ADR Integration (Post-Production)

The sound mixer receives the ADR files:

1. Timing Adjustment:

• ADR may differ slightly in timing from the original
• Sound mixer shifts the ADR take temporally to synchronize perfectly

1. Sound Matching:

• ADR was recorded in the studio (dry acoustics)
• Set audio had room reflections
• Sound mixer uses EQ and reverb to bring ADR closer to set audio

1. Level Adjustment:

• ADR levels are adjusted to the level of the original dialogue

1. Blending:

• Sometimes clean parts of the original dialogue can be retained
• ADR is only laid over problematic parts

1. Final Export:

• Integrated ADR/original mix is finalized

Common ADR Problems

Costs and Budget for ADR

Cost Example:

• 20 problematic lines
• Average of 3 takes per line = 60 takes total
• With talkback and resets: 3 hours session = €900 (Studio) + €300 (Supervisor) + €600 (Actor) = €1800

For comparison: An additional day of sound mixer on set (€800) might have prevented 50% of this ADR.

Best Practice: Avoiding ADR

The best ADR is the one that is not necessary. To save ADR costs:

1. Good Sound Crew on Set

• Experienced sound mixer and boom operator
• Correct equipment

1. Wildlines Strategy

• Record wildlines immediately after every problematic line
• Avoids 80% of ADR necessity

1. Location Quality

• Acoustic assessment before shooting begins
• If too loud, choose a different location or schedule quiet times

1. Post-Production Audio Repair

• iZotope RX can remove many disturbances (aircraft, wind noise)
• For these cases, you don't need ADR, just audio repair

Summary

ADR is a necessary evil in film production. A well-executed ADR session is professional and unobtrusive – you don't notice that dialogue has been re-recorded. Poorly executed ADR is immediately recognizable (artificial, mistimed, different sounding).

Best Practice:

• Minimize ADR (not maximize) through good on-set sound work
• Wildlines as the first choice for problems
• ADR only as a last resort
• If ADR is necessary, then with an experienced ADR supervisor and a professional studio

The ideal film has 0% ADR – 100% original set dialogue. In reality, a 5-15% ADR rate is normal; over 30% ADR means the on-set sound team was not good enough.