Results of comprehensive study of the DSM effect are given. The all main parameters of LCM were varied in the broadest range. A unified experimental technique was used. We did not find essential inconsistencies with the earlier published data. Simultaneously we observed a number of phenomena not described in the literature such as:tertiary DSM (DSM),non-DSM2. In detail ,experimentaly we investigated thr effect of main parameters LCMs on them electrooptical characteristics. The attempt of explanation of some results is made. A idea of multilayer structure of the scattering LC layer is developed.