Apparatus for processing all audio signal comprising a sequence of blocks of spectral values: a processor for processing the sequence of blocks using at least one first modification value for a first block to obtain aliasing-reduced or aliasing-free first result signal in an overlap range and using at least one second different modification value for a second block of the sequence of blocks to obtain an aliasing-reduced or aliasing-free second result signal in the overlap range; and a combiner for combining the first result signal and the second result signal in the overlap range to obtain a processed signal for the overlap range, wherein the processor comprises: a modifier (510, 509, 508, 507) for modifying the first block of the sequence using the at least one first modification value to obtain a first modified block, for modifying the second block of the sequence using the at least one second modification value to obtain a second modified block, for modifying the second block using the at least one first modification value to obtain a third modified block and for modifying the first block using the at least one second modification value to obtain a fourth modified block; a spectrum-time converter (501, 502, 503, 504) for converting the first to fourth modified blocks into a corresponding time representation (561, 562, 563, 564); and an overlap-adder (505, 506) for overlap-adding time representations (561, 563) of the first and third modified blocks (551, 553) to obtain the first result signal and for overlap-adding time representations (562, 564) of the second and fourth modified blocks (552, 554) to obtain the second result signal. a processor for processing the sequence of blocks using at least one first modification value for a first block to obtain aliasing-reduced or aliasing-free first result signal in an overlap range and using at least one second different modification value for a second block of the sequence of blocks to obtain an aliasing-reduced or aliasing-free second result signal in the overlap range; and a combiner for combining the first result signal and the second result signal in the overlap range to obtain a processed signal for the overlap range, wherein the processor comprises: a modifier (510, 509, 508, 507) for modifying the first block of the sequence using the at least one first modification value to obtain a first modified block, for modifying the second block of the sequence using the at least one second modification value to obtain a second modified block, for modifying the second block using the at least one first modification value to obtain a third modified block and for modifying the first block using the at least one second modification value to obtain a fourth modified block; a spectrum-time converter (501, 502, 503, 504) for converting the first to fourth modified blocks into a corresponding time representation (561, 562, 563, 564); and an overlap-adder (505, 506) for overlap-adding time representations (561, 563) of the first and third modified blocks (551, 553) to obtain the first result signal and for overlap-adding time representations (562, 564) of the second and fourth modified blocks (552, 554) to obtain the second result signal. a modifier (510, 509, 508, 507) for modifying the first block of the sequence using the at least one first modification value to obtain a first modified block, for modifying the second block of the sequence using the at least one second modification value to obtain a second modified block, for modifying the second block using the at least one first modification value to obtain a third modified block and for modifying the first block using the at least one second modification value to obtain a fourth modified block; a spectrum-time converter (501, 502, 503, 504) for converting the first to fourth modified blocks into a corresponding time representation (561, 562, 563, 564); and an overlap-adder (505, 506) for overlap-adding time representations (561, 563) of the first and third modified blocks (551, 553) to obtain the first result signal and for overlap-adding time representations (562, 564) of the second and fourth modified blocks (552, 554) to obtain the second result signal.