Connecting USB speakerphone to PC 

graphic of how to plug in a usb cord
  1. Connect the USB cable to the USB port on the back of the speakerphone.
  2. Connect the other end of the USB cable to the USB port on your computer. A blue light will illuminate through the buttons on the top of the unit indicating the speakerphone is powered on and operating.​

Using your P420-M USB speakerphone

Volume up, volume down and mute

speaker labeled for volume down, mute key, and volume down button

1.  Press the down arrow (left button) to decrease the speaker volume.

2. Press the up arrow (right button) to increase the speaker volume.

NOTE: A prolonged press of the volume buttons will increase or decrease the volume several levels until you stop pressing the button. The P420-M will beep when a volume up button or volume down button is pressed and a series of beeps when a prolonged press is performed. Each beep signals one level of volume increase or decrease.

3. Press the microphone icon (middle button) to mute the microphone. A blue light will flash indicating that the microphone is muted.

4. Press this button again to unmute. The blue light will become solid indicating the microphone is unmuted.

External speakers/headphones Connection

speaker labeled for stereo jack and USB port

The P420-M is equipped with a 3.5 mm stereo headphones/external speaker connector. Connecting your computer’s loudspeakers (or headphones) to the P420-M will disable the P420-M’s internal speaker. Your computer’s audio (music, VoIP communication or any other) will be passed through to the external speakers, maintaining the same sound quality your computer can deliver. While the internal speaker is disabled when using this connection, the P420-M’s internal microphone is still functional.

Confirming Plantronics Calisto P420-M  as Microsoft Lync 2013 speakerphone

The P420-M works plug-and-play with Microsoft Lync 2013 and requires no drivers or additional software. For most computers, the P420-M should become the default speakerphone device when connected to your computer. To ensure the P420-M is configured properly as the Microsoft Lync 2013 speakerphone, follow these steps:  

1. Click the show menu option on the upper right-hand corner.

red arrow pointing to settings drop down menu

2.  Select the “Tools” option

3. Select “Audio Device Settings”

 4.  Now  in Audio device :  Plantronics P420-M will automatically be selected.

Lync - Options window. highlighted - select the device you want to use for audio calls: speakerphone.

5. Click Ok

6.  If the speaker phone is not auto selected , then select Plantronics P420-M in the drop-down lists under "Select the device you want to use for Audio settings", and then  Click ok.

You are all set to use the Plantronics P420-M speaker phone.

Article number: 
Last updated: 
January 16, 2014