Meyer Sound has introduced M-Noise, a new test signal that will promote standardised measurement of a loudspeaker system’s maximum linear output.
A mathematically derived test signal that effectively emulates the dynamic characteristics of music, M-Noise enables a far more accurate measurement of a loudspeaker system’s linear peak SPL in any application requiring reproduction of musical content.
The mathematical formula for generating Meyer M-Noise was derived following extensive spectral analysis of a wide variety of music program material. In particular, the analysis measured the varying crest factors in music, and how these measurements compared to pink noise. It was discovered that the crest factors of music and pink noise were similar at frequencies below 500 Hz, but with music exhibiting a steadily rising crest factor at higher frequencies.
“It’s vital to have an accurate and consistently repeatable way to measure the linear peak SPL of a loudspeaker when reproducing music,” said Vice President and Chief Loudspeaker Designer Pablo Espinosa. “Pink noise may get you in the ballpark but you still could be off by 6 dB or more when you switch to music program. However, if you measure your maximum level using M-Noise, following our recommended procedures, you will know for certain your real-world limit for sustained, linear and full-bandwidth music reproduction. The procedure is consistent and repeatable, and it gives you full confidence that your system will have the headroom required for accurate reproduction of dynamics without compression.”
Additional information and a free download of the Meyer M-Noise file are available on Meyer Sound’s dedicated M-Noise web site, m-noise.org. File format is 96 kHz WAV with a size of 10.2 MB. Playing time is 53 seconds but playback can be looped indefinitely.
The new Meyer M-Noise site includes three informative videos. A short overview (4 minutes) summarises the technical solution offered by Meyer M-Noise and outlines the development process. For audio professionals who want more background, M-Noise: A New Test Signal (8 minutes) explains the fundamental concepts behind pink noise, demonstrates the different crest factor characteristics of music and pink noise and reviews the methodology behind deriving Meyer M-Noise. The third video, M-Noise: Practical Use (14 minutes) describes the measurement equipment required to effectively use Meyer M-Noise, and details the step-by-step procedure for precisely determining the linear peak SPL of a loudspeaker system. The Real World SPL video (6 minutes) serves as a prerequisite to watch before the two technical videos.
Meyer M-Noise can be used to determine the linear peak SPL of any loudspeaker system, regardless of manufacturer, size or design. However, the accuracy and consistency of results will depend on the type and quality of the test equipment and adherence to the proper measurement procedures.
Meyer M-Noise was introduced at the 145th AES Convention in New York in late 2018.
“At Meyer Sound, we are constantly pursuing new ways of measuring and analysing what we experience when we listen to music,” said Meyer. “By uniquely combining the consistency and repeatability of a test signal with the real-world dynamic complexity of music, M-Noise provides audio professionals with a powerful new tool for system calibration.”
