I am trying to adapt an external dynamic microphone for use with my Exhibit 4G. I bought a 3.5mm PRRS plug with three discrete shielded stripped end cables (White=Left Audio, Yellow=Right Audio, Red=Mic), a PRS inline jack, and a female XLR mic connector. Using the PRRS pinout of P=Left Audio, R1=Right Audio, R2=Ground, and S=Mic, I soldered the shields of White and Yellow to the sleeve of the PRS jack, White to the pin and Yellow to the ring. My stereo headphones work perfectly with this arrangement. I then soldered the shield of Red to ground of the XLR and Red to audio. I then successfully tested all connections from the PRRS plug to the PRS jack and the XLR connector with an ohmmeter. When everything is connected, the headphones still work the same but the phone doesn't "hear" the external mic or disable the internal mic like it does with the headset that came with the phone. What am I doing wrong? Any ideas? Thanks!