I have tried to implement ISIB (Index Selectable Ind. Band Filter) in ADAU1701 and I have no problems with it. Now, it seems like the ADAU1452 DC block input is causing confusion on the filter index select pin because output seems weird and distorted even if the index filter has its filters disabled or flat . Tried 32.0 and 28.4 DC input formats to no avail. On the ADAU1701 the 28.0 format works perfectly. Is this a bug on the numbering format or just me being having a mistake implementing?