The A2-2000 cannot mix audio together - it's purely a router. So in Dual PIP mode on a C2-7000 series unit, the A2-2000's first output follows window 1A, and the 2nd output follows window 1B.

No mixing can occur, only audio routing / selection and volume / balance control.

For powerful audio mixing, the C2-7310 with additional A2-7000 series units will perform full audio mixing with delay and SD/HD-SDI embedding/de-embedding