Do you have ?:
1. The front left set as master in the config program? This can sometime default to Centre.
2. You point the MSR at electronics AND this speaker when you press clear, so they can all receive the 'clear' command directly from the MSR.
3. The speakerlink cable for this AC12 front pair of DSP8000 connected to the 'Master' column of speakerlink connectors on the 861. (The ones with the green stripe next to them)
4. You are using either an M lead from the AC12 to the front left DSP 8000 with the pins linked in the S connector, or with an S lead with the S din cut off and replaced with a BNC connected to the Master BNC on the AC12. (AS per AC12 blues)
5. You have the two DSP 8000 connected together with S comms and then another S Comms from the right DSP8000 back into the S comms socket on the AC12.
Rick