These cables are designed to enable a normal microphone that has a 3-pin XLR output and unbalanced (mono) signal, to be connected to devices that have a stereo (Left and Right channel) input. The mono signal from the mic, is sent to both the Left and Right channels on the stereo input.

Using a regular “balanced” XLR to 3.5mm cable, can mean the “inverted balanced” signal (Pin3) gets sent to either the Left or Right channel (Ring) on the stereo input. This will result in a weird hiss sound on 1 of the channels (Left or Right).

A microphone outputs a “balanced” signal, which is also “mono” (1 audio channel). If you need to connect a mic to a 3.5mm “stereo” input, such as on an iPod, PC sound card or HD camera, a cable like this is required to SPLIT the “mono” signal into a “stereo” signal, so it reaches both the LEFT and RIGHT side of the 3.5mm stereo input.Devices with stereo 3.5mm “mini jack” inputs include digital video cameras and laptop and desktop computers.

Though with computers, note that different sound card manufacturers do things quite differently and these mic inputs (usually coloured PINK and with a little mic symbol), some can be stereo, though others are only mono, but with a splitter automatically built in to send the signal to both left and right inputs on the recording software.

Wiring:
XLR Pin1 = TRS Sleeve
XLR Pin2 = TRS Tip
XLR Pin2 = TRS Ring
XLR Pin3 = TRS Sleeve

unbalanced 3.5 mm TRS JACK to 3-pin XLR female Wiring diagram

If you need to know more about unbalanced to 3.5mm stereo Cable, check the products on the website, http://propaudio.com/product/bxj05-basic-3-5mm-mini-jack-balanced-microphone-cable/

BXJ05 Basic balanced Microphone Cable for 3.5 TRS mini JACK