A microphone jack is a small round outlet, usually on a computer, camcorder, or stereo, into which a microphone cord is plugged. The jack, sometimes called a mic jack, is an input connector that works much like an electrical socket. Plugging a microphone into a jack enables it to send its sound into the computer or other device.
In home filming and recording endeavors, microphones are more often than not plugged into machines, such as computers, that can store and edit the sound. The microphone jack is how the microphone's cable or cord connects to this technology. Once the microphone is plugged in, the computer, stereo, or other device is able to receive and translate the mic input. This input can then be converted into audio files or editable recordings.
Most of the time, a headphone jack can double as a microphone jack. So long as a port is designed for converting audio signals, it can typically be used for any sort of audio equipment, microphones included. Audio jacks are commonplace on most modern electronics, including stereos, karaoke machines, smartphones, and both laptop and desktop computers.
When an audio port is not readily available, a microphone jack adapter may be required. A jack adapter converts some other input source into an audio port. Most adapters use universal serial bus (USB) ports.
Just because a microphone has a cable does not necessarily mean that it will fit into a given microphone jack. Jacks typically range from 2.5 to 3.5 millimeters (about 0.10 to 0.13 inches) in diameter. Microphone cables are less uniform. Some are designed to fit into jacks, but others are designed to fit into more traditional XLR connections.
An XLR connection is the standard connection for most professional-grade audio equipment, including amplifiers and synthesizers. These kinds of connections are characterized by multiple prongs, usually between three and seven. The prongs fit into dedicated XLR jacks.
One of the biggest benefits of the XLR jack is its stability. With multiple prongs, the cable is more secure, and less likely to come loose inadvertently. It is rare for a computer or other mainstream electronic device to have an XLR input, however. In order to connect a microphone to a standard microphone jack, an XLR adapter may be required.
XLR adapters work just like traditional microphone jack adapters. They usually have an XLR receiver on one end, and a jack input plug on the other. Once the XLR end is snapped into the microphone cable, the microphone can be plugged into the jack.