Final Sample Overview

DEFINITION
‘Final sample’ is to record ‘clean,’ usable production dialog performances that, with minimal post production sound processing, carries to and through final sound mix and mastering. Digital audio is measured in ‘sample’ units, digital images are measured in ‘pixel’ units. Virtual production producers strive to carry the digital images displayed on the LED walls and captured in camera all the way to final picture mastering with little to no additional post production visual effects processing in between. ‘Final pixel’ is the term used to describe this goal. Final sample is to audio what final pixel is to picture.

ZADR GOAL
When dialog performances are well recorded where the tracks carry over to final sound mix without significant post production processing – light echo & noise removal, and little to no automated dialog replacement (zero ADR or ZADR) – then ‘final sample’ is achieved. The audio sample recorded on set is the audio sample delivered to audiences.

Automated Dialog Replacement (ADR) is a poor substitute for an actor’s actual on-set production dialog performance. For most actors, vocal performances are all but impossible to recreate in an ADR setting. Additionally, conflicts with actors’ schedules can make ADR sessions difficult to arrange, sometimes pushed too close to final sound mastering delivery deadlines.

PROBLEMS
Picture’s solution creates Sound’s problem. The sought after benefits of in-camera visual effects (ICVFX) or final pixel potentially gained from shooting in a volume or extended reality (XR) stage comes at the detriment of production sound recording.

LED paneled volume stages are built and designed to support virtual production. Ironically built within ‘sound stages,” LED volume interiors are notoriously challenging acoustical environments, difficult within which to record ‘clean’ non-reverberant dialog.

Reflection: Virtual production stages vary in size and design. Most are semi-circular, “J,” or closed “C” shaped. The walls stand 20+ foot tall, internally faced with glass-plated LED panels. Many volumes are capped with a ceiling of downward facing LED panels. The walls and ceilings typically rest over a floor of polished cement. The overall effect is a superb echo and whisper chamber. The hard, acoustically reflective surfaces and perpendicular angles of LED paneled stages support an extremely reverberant experience as compared with traditional production sound stages.

Noise Magnification: The circular shape of volume stages accentuate captured room noise more so than traditional sound stages. Shaped like a large parabolic microphone, any noises generated toward the open front of LED stages get picked up and magnified within the stage. Sounds such as creaky director’s chairs, dropped items, whispered conversation, and noisy keyboards are naturally magnified and easily captured in dialog recordings.

Noise Generators: Compounding this acoustically hyper-sensitive sound magnet are the additional noises generated by the increased personnel (virtual art department, camera tracking and frustum, stage operations, technical support, etc.) and technologies needed to drive and actively support on-set virtual production (servers, vendor carts, workstations, panel fans, etc.). So not only do volume stages more readily capture room noise, the technologies and personnel needed to support volume stages generate more noises to capture.

Highly reflective surfaces, shaped in a hyper-sensitive noise trap, surrounded by additional noise generating personnel and technology unfortunately work in concert to create an extremely difficult environment within which to record clean, usable production dialog performances, without the need of ADR support.
 
SOLUTIONS
No silver bullet to eliminate reflection and noise exists . . . there is no one-size-fits-all solution to extinguish a production sound mixer’s virtual production dialog recording nightmare. An holistic, collaborative, pre-visualized and executed approach can reduce reflection and  noise well enough to give post sound editors a fighting chance at cleaning production dialog tracks and avoid ADR.

Eric Rigney