Calibration of a distributed sound reproduction system

A system for calibrating a distributed audio rendering system, comprising a set of N heterogeneous speakers controlled by client modules controlled by a server, the calibration system comprising:

• a microphone which, placed in front of a first speaker of the set, is able to capture a calibration signal sent to the first speaker at a first time and rendered by this speaker, to capture the calibration signal sent alternately with a known time shift to the N−1 other speakers of the set and rendered by these N−1 speakers, to capture the calibration signal sent to the first speaker at a second time and rendered by this speaker and to iterate the capture operations for the N−1 other speakers of the set, and
• a processing server which is configured to collect the captured calibration signals, analyze the captured and collected calibration signals, including multiple detections of peaks of impulse responses obtained from the captured calibration signals, a maximum peak being detected by taking into account an exceedance threshold for the detected peak and a minimum duration between two detected peaks, in order to obtain N*(N+1) timestamp data, in order to determine a plurality of heterogeneity factors to be corrected and calculate corrections for the determined heterogeneity factors and to transmit them to the various client modules of the corresponding speakers in order to apply the calculated corrections.

A non-transitory computer-readable storage medium on which there is recorded a computer program comprising code instructions which when executed by a processor of a calibration system, configure the calibration system to calibrate a distributed audio rendering system, comprising a set of N heterogeneous speakers controlled by a server:

• a) capturing, by using a microphone placed in front of a first speaker of the set, a calibration signal sent to the first speaker at a first time and rendered by this speaker;
• b) capturing, by using said microphone, the calibration signal sent alternately with a known time shift to the N−1 other speakers of the set and rendered by these N−1 speakers;
• c) capturing, by using said microphone, the calibration signal sent to the first speaker at a second time and rendered again by this speaker;
• d) iterating steps a) to c) for the N−1 other speakers of the set;
• e) determining a plurality of heterogeneity factors to be corrected for the set of the N speakers by analyzing the calibration signals thus captured including multiple detections of peaks of impulse responses obtained from the captured calibration signals, a maximum peak being detected by taking into account an exceedance threshold for the detected peak and a minimum duration between two detected peaks, in order to obtain N*(N+1) timestamp data;
• f) correcting the determined heterogeneity factors.