Zone 2 should work fine for this. But, you do need to use the Zone 2 remote control to select the audio source you want to come out on the Zone 2 audio outputs. You can then listen to whatever you want on Zone 2: Tuner, CD, TV, AUX, etc. independent of what the 990 is sending to the mains.
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Outlaw 990 Preamp/Processor
Outlaw 7125 7-Channel Amplifier
Outlaw LFM-1 Plus Subwoofer
Paradigm Mini Monitor V.3 Fronts
Paradigm CC150 Center
Paradigm ADP-170 Bipole Surrounds