I have the 3CX softphone configured on a few installations. These installations use a Plantronics 638 wired headset. The audio options are set as desired. However when in a call, you cannot click the speaker button to go to loud speaker mode, it is greyed out. Audio Options are configured as: Microphone - Headset Speaker - Headset Ringing = PC Speakers Is it possible to go from using the headset, to loud speaker mode somehow?