Do other phones sound OK?

As FSETH notes, only the driver's door midrange speaker produces phone sound. The other speakers are silent.

One cause of poor caller audio is the location of the Bluetooth antenna or a disconnected BT antenna. The E46 official BT antenna location is on the back side of the center console-- under the arm rest. Look there to verify the BT antenna is solidly connected. Then, check that the BT antenna cable is solidly connected to the TCU or ULF module in the trunk. That is located on the electronics stack above the CD changer.

Since you describe the clarity issue as both way (callers can't hear you and you can't hear callers), I suspect something related to the BT antenna. If other phones are OK, then you know it is the handset. If other phones are also problematic, then investigate the BT antenna and cable.

If BT caller audio is only bad with the Sprint EVO 4g, it could be a problem with Sprint's Andriod BT stack or a BT antenna problem with your specific handset. Andriod phones are notorious for having problems with advanced BT hands free systems.

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