Measurement of Loudspeaker Frequency Response with Matlab

Frequency response measurement of a loudspeaker using Sound card.

The code presented here concerns the frequency response measurement of a loudspeaker. The measurement technique is based on generation of a set of sine-wave tone signals with one and the same level, reproduction of every signal by the loudspeaker and measurement of the SPL by measurement microphone. Then the transfer function (i.e. the amplitude ratio of the output/input signal) is calculated for every given frequency and finally the frequency response is plotted. For better results a data strobe is performed and StobeChoice.m file is provided, so one can choose the range of the input data used for the measurements. The code provides:
1) plot of the normalized frequency response of the loudspeaker;
2) data.txt file with the measurement results (for post-processing).

The code is based on the theory described in:

[1] T. Rossing, M. Schroeder, W. Hartmann, N. Fletcher, F. Dunn, D. Campbell, A. Pierce. Handbook of Acoustics. Springer, New York, 2007.

[2] H. Miller. 3-dimensional acoustic measurements using gating techniques. Bruel&Kjaer Application notes 17-163, 1976.

[3] H. Zhivomirov, I. Iliev. Radiation Pattern Measurement with Matlab Implementation. Journal of the Technical University of Gabrovo, ISSN: 1310-6686, Vol. 52, pp. 73-76, 2016. (http://epubl.tugab.bg/documents/cat_view/46-----/61--52-----)