I'm sending a 24 bit signal into my Finalizer but the Finalizer says it is only 20 bits in the TOOLS/DIO menu. Is there something wrong with my Finalizer ?
The reason for this is likely a difference between the status bits and the actual audio data.
The status bits read by the Finalizer most likely reads 20 bit, while the audio data is still 24 bits. Unfortunately this is not an uncommon mistake in various digital equipment on the market.
The reason is that the status bit is generated as a code in the sending device and thus has no relation to the actual audio-bits. The Finalizer simply reads the status bit as the info-data it is and writes it on the DIO page. The Finalizer cannot detect the actual audio resolution.
Depending of the type of sending device you can send status bits containing information about the word-length, emphasis-type, copy-protection (only when sending S/PDIF statusbits), samplerate, source- and destination device and whether the audio data is valid or not (CRC).
All these status bits do NOT affect the actual audio.
E.g. on some devices (for instance an AudioPrecision generator) you can send status bits informing that the transmitted audio is a 32kHz, J17-emphasis'ed coming from a "SRC1"-device even though the output is 48kHz, linear, and its origin is an AP1D.
All in all: the status bit should tell the truth, but sometimes the manufacturer forgets to set them correctly - AND - sometimes the user can set them himself/herself.