In-line surface wave reflector filter with measures to prevent the occurrence of direct crosstalk between the input (2) and output (4) transducers. For the first in-line track there is a second transducer system with an input (12) and output (14) transducer in which the input (2, 12) or output (4, 14) transducers in both systems have the same structures but the equal-strength signals of the direct crosstalk are in opposite phases at the output terminals of the two transducer systems.