• In the relative system, there is a calibrated, reference volume at which movies are played in theaters, which is duplicated in your environment and referred to as “0 dB.” Regardless of how large or how small the theater, a setting of “0 dB” is always the same, known volume. Changes from that volume level are shown as either positive (louder) or negative (quieter). People who have spent any time making recordings will recognize that this is similar to the notion of “0 dB” on a record level mete