(pronounced "Melissa") ( maximum-length sequences system analyzer) Trademarked name for the first MLS measurement instrument designed by DRA Laboratories (Sarasota, FL). Maximum-length-sequences methods were used for room impulse response measurement by M.R. Schroeder in 1979 (based on work dating back to the mid-60's); however, it was not until 1987 that the use of MLS became commercially available. The first MLS instrument was developed and made practical by Douglas Rife, who described the principles in his landmark paper (co-authored by John Vanderkooy, University of Waterloo) "Transfer-Function Measurement with Maximum-Length Sequences" ( J. Audio Eng. Soc., vol. 37, no. 6, June 1989), and followed up with new applications described in "Modulation Transfer Function Measurement with Maximum-Length Sequences" ( J. Audio Eng. Soc., vol. 40, no. 10, October 1992). Further information available directly from DRA Laboratories .

MLSSA is an acronym for 'maximum length sequence system analyser'. Such analysers have become standard in the testing of loudspeakers and listening rooms for colouration caused by resonance effects.