Is the STA309a stereo input configured correctly for 2.1 out

[dometoeer]

Hi!
The STA309a documentation is a bit lacking on this topic, so some explanation is needed.
Required configuration:
Single stereo I2S input on SDI12
Two I2S outputs: stereo to main speakers and mono to subwoofer
problem:
1. What is the correct output for I2S mapping: SDO12 to the main speaker, SDO56 to the subwoofer (right or left)?
Can you tell if the following configuration is correct?
Enable AMBMME and AMBMXE bits (bass mixing and crossover)
CSS and RSS are set to 10 (closed)
SUB is enabled
FSS and XO positions are set according to the speaker configuration
Thank you!