The paper presents results of photoacoustic studies of the thermal diffusivity of CdTe and Cd1-x-yBexMnyTe crystals. The drum effect strongly influences the photoacoustic characteristics that have been measured. The values of the thermal diffusivity of the crystals have been extracted from the amplitude and phase frequency characteristics measured in reflection and transmission configurations in the Sf/Sr and Phase-Lag method. This paper presents that it is possible to extract simultaneously the thermal diffusivity and a drum factor B from photoacoustic frequency measurements. (C) 2015 Elsevier B.V. All rights reserved.