The Sennheiser MKH 418S professional stereo shotgun microphone incorporates the Mid / Side (M/S) technique, yielding a high degree of directivity and focus while reproducing signals with extreme accuracy to their perspective placement, within the Left / Right Stereo field.

The MKH 418S features 2 independent acoustic systems for generating the mid and side signals. The mid (M), or mono signal is generated using an internal shotgun microphone. With its frequency range of 40 Hz to 20 kHz, the shotgun accurately reproduces audio with extreme focus, emphasizing pick up of signals at the direct-axis section (front). The shotgun also rejects signal at the off-axis sections (sides) of the microphone, minimizing noise and further strengthening the pick up area. The Side (S), or stereo signal is generated using a separate, internal microphone system that features a figure-of-eight polar pattern. This system is responsible for reproducing the spacial character needed for accurate placement of signal within the stereo field. It can also handle 130 dB of SPL. 

The output features a 5-pin XLR male connection, capable of sending the separate signals of each internal microphone system to discrete channels of a console, field mixer, recorder or matrixing system. Each internal microphone requires +48V phantom power, supplied via two Sennheiser MZA 14 P48 battery power supply units, or any mixer capable of supplying at least 2 discrete channels of phantom power.