The M152 uses the same element as the M150 microphone. The difference is in the wiring inside the 5 pin connector. The M150 is wired so that it uses the pin 4 source resistor built into Lectrosonics belt pack transmitters such as the UM100, UM200, UM400 and LM. The M150 is wired as a three wire microphone with the bias being fed to the drain of the internal FET and the audio coming from the source of that FET.
The M152 uses a 3.3k source resistor built into the 5 pin female connector. The audio is picked up from the drain of the internal FET. This arrangement gives much better results with the SM transmitter and is still fully compatible with other Lectrosonics transmitters. The reasons for this new input arrangement on the SM transmitter are given in the link at the end of this FAQ.
The M152 is exactly like a two wire biased microphone and the M150 is a three wire biased microphone. Like all mics that can be wired either 2 or 3 wire, the M152 has opposite polarity compared to the M150. If you are using the M150 with the M152 you should reverse the phase using the receiver menu on one of the systems.
The sensitivity of the M152 is about 7 dB lower on a UM100 or UM200 compared to a M150. The sensitivity is almost exactly the same on a UM400. The sensitivity of the M152 is about 6 dB lower on a SM again compared to a M150. The sensitivity of the M152 is about 3 dB lower on a LM transmitter. These variations are easily adjusted with the transmitter gain controls.