Journal Article
Schottky's Law of Low-Frequency Reception for Modern Sensitivity Conventions
Journal of the Audio Engineering Society · Volume 69 · Issue 11 · pp. 860–870 · November 2021
Abstract
Acoustic reciprocity is a well-known and established concept, first proposed by Helmholtz and Rayleigh in the late 19th century. Acoustic path reciprocity has been extensively studied in the context of impulse response measurements as it allows us to interchange the locations of sensors and receivers without affecting the measurement. Electro-acoustic transducer reciprocity (also referred to as transducer reversibility) has been less studied. This work presents a literature overview of the science behind acoustic transducer reciprocity, namely Schottky's law of low-frequency reception,‡ and proposes a variant of this law that accounts for modern loudspeaker sensitivity conventions.While the proposed variant applies to all reversible transducer designs, a concrete specification is given for electro-dynamic moving-coil transducers. Furthermore a joint empirical validation of the original and proposed variants of the law is presented. Finally a hybrid empirical-theoretical scheme is proposed that uses the measured frequency response of the transducer used non-reciprocally along with Schottky's lawto predict the frequency response of the transducer used reciprocally.
