Combining the energy of different channels, generally to cancel noise. Mixing usually implies that no time shifting is involved before the data are combined. Also called compositing. 1. Modern processing combines data by various stacking (q.v.) operations, which usually are not called mixing. See Figure S-20. Coherency filtering and other processing techniques also involve mixing. 2. Mixed records often preserved two or more traces unmixed so that they would not be distorted by the mixing. Mixing was usually not done between channels on opposite sides of the source or from one record to another.