Automated Dialogue Replacement (ADR recording) is the process of rerecording production dialogue in a professional studio after shooting a film. This is done for a number of reasons. There could be technical problems with the production audio (too much bleed from another actor’s voice). There could be a distracting sound in the background during the best take. Maybe the actor off was off mic (it’s too late to fire your boom operator). In specialty films like musicals, on-screen dialogue and singing is always replaced. Studios also require a TV-safe version without profanity. In this case, another visual isn’t substituted, only the sound. It’s time for ADR recording.
Audio quality can make or break an indie film… or any film for that matter. The industry has been fixing it in the mix for almost 100 years. By the late 1930s, most Hollywood film production audio was redone in post. Today, many indie film producers have been told that ADR recording is evil because of the time and expense. But ADR and post-sync sound allows filmmakers to be free from the technical constraints of production sound limitations. Unless you have clean location sound, ADR is highly recommended and an expected part of any professional production workflow.
“Visual ADR” is the process of having an actor listen to dialogue and attempt to match it while watching a performance on screen with no sound. “Audio ADR” is the process of having an actor recite the dialogue along with the recording (heard in headphones) over and over again to reproduce the line with the right inflection and intonation.
If the entire scene is recorded during ADR, then you don’t have to worry as much about matching location ambience. It can be faked. However, extended recording of scenes can be time-intensive, so if you just need a couple of lines, relying on a professional engineer in a professional ADR setup is essential.
The video below gives a solid background on ADR recording… it’s history and process. But professional recording studios diverge slightly from this tutorial, which incorporates the Adobe Audition workflow instead of Pro Tools HD, the industry standard. Even in productions with a modest recording budget, video editors export files (ADR lines) specifically for Pro Tools engineers to use in an ADR session. Actors do watch a loop over and over again and there’s usually a 3pop right before the line to prepare the actor. Also, Pro Tools engineers don’t have to cut and paste lines to loop them during recording. The loop feature is built into the software and can be used in the recording process with less preparation. This tutorial video also uses a lower end mic (Rode NT1). The professional standard is a Sennheiser 416 or similar hi-end mic typically recorded into a tube preamp with a compressor/limiter before going into a digital audio workstation.
Every line is prepped beforehand so when an actor arrives, he or she can jump right into recording. When running an ADR recording session, microphone placement is important… just like during location recording. The location ambience is also a huge component of the overall sound. Because studio recordings tend to be super clean compared to location recording, engineers attempt to match the original on-screen sound with a reverb; this effect can be turned on during ADR to simulate the “feel” of the scene. It allows the producer to see the end product of the recording before the final mix instead of a sterile hi-end re-telling of a scene. Professional engineers have these effects for ambience and EQ settings ready to go to match the production sound. Even though this kind of processing is applied during the final mix, it’s also incorporated during the recording process to allow both actors and producers to see past the differences between hi-end studio sound and location sound. The producer can choose a “select” take on the spot before going to the next line. This actually saves time and money (paying for a proper studio space). Alternate takes are saved as a backup. After the actor is dismissed, the engineer can zoom in and slip syllables in time down to the millisecond and change pitch to match the proper vocal inflection and on-screen timing. The final ADR track is then incorporated in the final audio mix before layback to the video editor.
Plug-ins can be applied to alter the pitch and timing of syllables, creating an exact (or even better) duplicate of the original. Without these tools (both the hi-end software and the engineer’s ears), ADR recording results can have both sync problems and “lip smack”. Even incredibly slight differences in timing between sound and picture are subconsciously annoying and even painful to watch. This unwanted result of the re-recording process can destroy an otherwise spectacular film. ADR done wrong can actually make a film worse. Lip smack noise is easily removed with plugins like Isotope RX or those found in the WAVES Restoration suite. But it’s not as easy as running a sentence through Isotope De-click and clicking “apply”. Engineers have to adjust the threshold of the click removal and the nature of the clicks being removed (high ticks or something closer to a knock). Also, just like with medication, every process applied to audio material creates an artifact. Too much De-click processing results in consonants being degraded and vowels becoming “squirrel-y”… so the negotiation between the degree of audio processing being applied and the negative results of the artifacts created as a result of plugins is the job of the engineer.
Filmmaker IQ’s great introduction to ADR recording clip on YouTube is below. We hope to see you on your next ADR, voiceover, music edit, or final mix session.