Phonometrical precision measurements during a high end classical music live recording and four standardized recording systems’ signal comparison

Discographical sound recording process is very seldom accompanied by real sound pressure, intensity and level measurements. Usually available data are often referred to mathematical extrapolations calculated on sound recording audio signals. This article investigates the situation defined as ‘‘real’’ from a scientifical point of view, having as a referring base a Swedish precision sound level meter fresh from calibration, during the stereophonic multichannel live recording session of the Philharmonische Camerata Berlin. Comparison among reference signal and eight high quality microphone capsules signals coming from four different stereophonic standardized microphone systems devoted to discographical purpose recording (XY, ORTF, Binaurale and AB) shows big differences among the respective signals and the same recording spot measurement system position. It is noticeable how differences even higher than 6 dB can make microphone positioning particularly critical. A standardizing method is proposed.