The present invention relates to a process for the preparation of a zeolitic material having a CHA-type framework structure comprising YO2 and X2O3, wherein said process comprises the steps of: (1) providing a mixture comprising one or more sources for YO2, one or more sources for X2O3, one or more optionally substituted ethyltrimethylammonium cation-containing compounds, and one or more tetraalkylammonium cation R1R2R3R4N+-containing compounds as structure directing agent; (2) crystallizing the mixture obtained in step (1) for obtaining a zeolitic material having a CHA-type framework structure; wherein Y is a tetravalent element and X is a trivalent element, wherein R1, R2, and R3 independently from one another stand for alkyl, wherein R4 stands for cycloalkyl, and wherein the YO2:X2O3 molar ratio of the mixture in (1) ranges from 2 to 1,000, as well as to zeolitic materials which may be obtained according to the inventive process and to their use.