Home Headset Installation FAQ Plantronics S11, S12 Headset System Frequently Ask Questions (FAQ)

Plantronics S11, S12 Headset System Frequently Ask Questions (FAQ)


Q. What is the difference between the Plantronics S11 and Plantronics S12?

A. S11 use the same amplifier base, but they come with different styles of headsets. The S11 headset is a simple headband style. The S12 replaced the old S10. Both include the same convertible headset, but the S12 amplifier is updated with a newer look and feel. The new S12 base does not include a tone controller.

Q. What is the “Firefly” feature on the Plantronics S12?

A. The Firefly in-use indicator light is a LED light on the end of the microphone that flashes when the headset is in use or “On Line” to let others know you are on the phone.

Q. Callers cannot hear my voice on the Plantronics S12/S11.?

A. There are a few things that may be causing this.

  • Make sure the mute button is turned off.
  • Increase the outgoing volume by adjusting the speak volume control. (see below)
  • Adjust microphone so it is closer to your mouth.
  • Check the configuration setting (see below) to be sure it on the correct setting
  • Check to be sure the unit has been installed correctly.

Q. How can I increase the volume of my Plantronics S12/S11?

Adjusting the Receive volume (what you hear):

  • This is controlled using the volume dial of the amplifier base.
  • On the Plantronics S11 the dial is labeled “Listen.” The S11 also have a dial labeled “Tone” which will change the bass/treble frequency of the incoming sound.
  • The Plantronics S12 has a soft rubber volume dial between the headset/handset and mute switches which will increase or decrease your listening volume.

Adjusting the transmit volume (how others hear you):

  • The Plantronics S11 and S12 all include two transmit volume adjustments. The TX setting adjusts the transmit level to HI or LOW, and the dial allows you to adjust the sound level within each range.
  • On the S11, the range setting is located on the left side of the amplifier labeled “Tx Level.” The transmit volume dial is on the top of the amplifier labeled “Speak.”
  • On the Plantronics S12, the TX setting and transmit volume dial are on the right side of the amplifier.

Plantronics S11 Volume Control

Plantronics S11 Volume Control


Plantronics S12 Volume control

Plantronics S12 Volume Control

Q. Where should my configuration switch be set at with the S11 or S12??

A. For most phones is should be set to either 1 or 4.

1- most phones
2- Definity phones
3- Merlin Phones
4- GE 2-9450 phones
5- Siemens phones
6- NW Bell phones

Please see the Plantronics compatibility guide for switch setting information.

Q. How do I install the Plantronics S12?
A. On the back of the S12 Base unit there are 2 ports. One says “Handset” and one says “telephone”. Unplug the “Handset” from the base of your existing telephone and plug it into the S12 base unit where it has the “Handset” icon. Then take the short cable that came with the S12 and plug it into the port on the base of the S12 where it has the “telephone” icon, Then plug the other end into where your “Handset” was on your existing telephone. Plug the headset into the port with the icon of a “headset” on it. Route the headset cord through the cable management channel on the bottom of the amplifier. Make sure the AC Power is plugged into the wall and the configuration setting should be on one where the call is clear to you and your caller.

Plantronics S12

Q. I don’t hear a dial-tone on my Plantronics S11 or S12. What should I do?

    • Make sure all cable connections are correct and firmly in place. Pay special attention that the handset cord is properly connected.
    • Ensure Ac power adapter is connected and the power is on.
    • Make sure you have pressed the headset button and the headset indicator is on.
    • Make sure the telephones handset is off hook .Adjust listen volume control.
    • Adjust the compatibility slide switch.
    • Ensure that the headset is centered on your ear.

Q. Can I buy a replacement headset for the S11 or S12?

A. Yes. This is the Plantronics S11 replacement headset (shown below).

Plantronics S11 Replacement headset

This is the Plantronics S12 replacement headset (shown below).

Please note: The S12 replacement headset is the headset only. No headband p/n 43298-01. You will need to purchase these item separately.

Q. Can I use an Plantronics H-Series headset or different headset with the Plantronics S11 or S12? A. No, The S11 & S12 are designed to be used with the specific headset it comes with.

Q. I hear a hum in the headset of the S11 or S12.?

A. Suggestions:

  • Adjust the compatibility slide switch until the sound is clear.
  • Try other switch settings (It will not harm the headset or your phone).
  • Try installing the headset on another phone in another location, if the hum is still present you may need to replace the unit.

Q. Can the headset on Plantronics S12 be worn on either ear?

A. Yes, the S12 headset can be worn on either ear. Wear the headset on either ear, then rotate the microphone boom so it is positioned along your cheek. The microphone should be positioned approximately 2 – 3 finger widths from the corner of your mouth.

Q. How do I make a call using the S12?

A. Put the headset on. Remove the telephone handset from the cradle and place it on your desk.if there is no dial tone in the headset make sure the headset button is pressed.Use your telephones keypad to make a call.When you are done with the call simply place the telephones handset back into the cradle to disconnect the call.

Q. The red light at the top of the box (just above TONE) keeps blinking on the Plantronics S11. It stays on for a while and then goes out. Is this normal?

A. Yes, this is normal. The red light flashing is an On Line Indicator Light and it is voice activated. This lets people know that you are on the phone.

Q. Is the headset on S11 and S12 Noise Canceling?
A. Yes, Both models have a noise-canceling microphones.