You're using pin 11? Any AC seen on pin 11, should be 350 mV rms for 60% deviation (3k on wideband FM). Is there Rx PL on the radio? In the CPS, under the radio configuration menu, accessory configuration tab there's Rx Audio type. This can be filtered or flat. Also check the basic tab on that page, watch the hook switch defeats PL checkbox if using PL. Lastly in the conventional personality channel settings, advanced tab, there's a pre/de emphasis setting that needs to match. Your deemph settings in software should compliment whats in the radio.