Cavern calibration process

Cavern's exact calibration process depends on the system it's used on. However, using pink noise for frequency analysis is strongly discouraged, as the error margin is too large. A full range frequency sweep for measurement, and a linear-phase parametric EQ instead of a third-octave one should be used for calibration.

Regular theatres and studios

These are the recommended settings for Cavern DCP creation and playback. The center of the microphone placement should be at 2/3 of the room from the screen, in the center. The correct microphone aligment is behind a seat, but at least the size of the microphone higher than the top of the seat, facing upwards. The room should be equalized to the X-curve (-3 dB/octave above 2 kHz), at the following peak sound pressure levels.

Peak channel sound pressure levels (-20 dB FS)

In regular theatres, Cavern-ready systems, even with custom layouts, must match the standard levels.

Channel Level
Screen channels (max. 45° from center on both axes) 85 dB
Low frequency effect channels 95 dB
All other channels 82 dB

Cavern theatres and studios

For Cavern-only content creation and playback, the channels can only be calibrated by peaking filters, based off a frequency sweep reading with at least 7 microphones positioned around the reference listening position, to a flat response with the error margin of 0.2 dB between 100 Hz and 16 kHz (25 to 120 Hz for LFE channels).

Peak channel sound pressure levels (-20 dB FS)

For a Cavern theatre, each individual channel must be capable of outputting 105 dB SPL at the center of calibration. The channel array peak is also the same, it must be enforced in the content creation process by the authoring tools.

Channel Level
Full range channels 85 dB
Low frequency effect channels 95 dB