Comparison table for the Primo Microphones
Sensitivity: EM258 -32±3dB WM61A -34±4dB
S/N Ratio: EM258 74dB WM61A 62dB
The Primo EM258 is identical to the Primo EM158 which is no longer available
Ultrasonic Response
While the EM258 is used mainly for receiving audible signals it is not limited to these frequencies. Like the now discontinued Panasonic WM-61A it has a useful ultrasonic response extending up to 95 kHz. We have done some tests and the EM258 performance exceeds that of the Panasonic WM-61A. Graphs to follow.
“The EM258 sound is clear and dynamic with a great sense of detail and a pristine stereo image.“ JF, Helsinki, Finland.















