Spatial timbre uniformity analysis of loudspeakers in rooms using MFCC

Spatial timbre uniformity needs to be considered during public address system design using loudspeakers. In this paper, an analysis based on Mel-frequency cepstrum coefficient (MFCC) was conducted on room impulse responses produced by different loudspeakers including conventional cone loudspeakers and a Distributed Mode Loudspeaker (DML). Histograms of Euclidean distances between MFCC vectors of each impulse response was plotted for each loudspeaker. The tail of the histogram which represents the frequency of larger distances was lighter in the histogram of the DML. The results imply that the DML can avoid extreme spatial timbre dissimilarity. The proposed method introduces concept of timbre uniformity, which could be helpful for designing acoustic spaces.