The Soundcraft RS2552SP is a ViO/3G/HD/SD SDI (serial digital interface) 16-channel de-embedder add-on insert card for the Soundcraft Vi Series. It's able to de-embed 8 or 16 audio channels from SDI-SD as well as SDI-HD video streams. For the D21m I/O system, it acts as an 8- or 16-channel audio input card. These two modes are determined by the configuration of hardware switches located on the card.

The SDI standard defines up to 16 audio channels that can be transmitted within a video signal. These 16 channels are then divided into 4 groups of 4 each. The user can determine via the hardware switches whether all 4 groups, only groups 1+2, or only groups 3+4 will be de-embedded.

The card hosts SFCs (sampling frequency converters) which are set to be bypassed by default. When bypassed, the SDI card is fully compatible for receiving embedded Dolby® E audio data. Or the SFCs can be enabled in case the audio extracted from the SDI stream is not in sync with the local system. So that means the mixing console can run fully independent of the video sync used for SDI. This card works at a sampling frequency of 48 kHz only.