GearHack: Revision: Single Pin Mono Headset Pin-Out

Older Revision of Single Pin Mono Headset Pin-Out

Revision: 20140116_220000 | All Revisions

Single Pin Mono Headset Pin-Out

The mono headset is a combined ear speaker and microphone used with many classic mobile phones and 2-way radios. It generally have a 3.5mm (mini) audio connector or a 2.5mm (sub-mini) audio connector (see photo below). Both sizes are standard in the audio world. It's single pin connector has three contacts.

This 1-pin connector is usually wired up in the following manner:

1 - ground
2 - speaker
3 - microphone

Based on the pinout above, the ground contact is shared with the speaker and microphone contact.

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Application Differences

Note that even though the pinout may be exactly the same from one Single Pin Mono Headset to another, there may be other differences. For example, as pointed out before, in some application the diameter of the connector differs.

But more importantly, we have found the connector to be different length between different applications. Take a look at the photo below.

As you can see the connector on the left is longer than the connector on the right. The connector on the left is from a generic security headset marketed for Motorola and Cobra 2-way radios. (See the "Advanced Nipple Covert Acoustic Tube Bodyguard FBI Earpiece Headset Mic PTT/VOX for 1-pin Motorola Talkabout Cobra Radio" link in "Related Links" section below.) The connector on the right is from the "Jabra Classic EarSet" for cellphones (see "Related Links" section below).

Our Jabra Classic EarSet did work with our Motorola TalkAbout MR350R radio in Push-To-Talk (PTT) mode; you can hear and send your voice through it. However, it did not work in VOX (voice activation) mode. Maybe the longer connector has something to do with it.

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Headset Examples

The following photo shows a security headset with a 1-pin connector for 2-way radios.

The following photo shows a Jabra Classic EarSet with a 1-pin connector for cell phones.

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