Ed Long (audio engineer)

Ed Long is an American audio engineer and inventor, best known for his pioneering work in Time Delay Spectrometry (TDS) and Maximum Length Sequence (MLS) measurement techniques, which revolutionized acoustic measurement and loudspeaker design. Long's contributions significantly improved the accuracy and efficiency of analyzing sound systems and room acoustics.

His development of TDS, later refined and popularized, enabled the isolation of direct sound from reflections and reverberation, providing a clearer picture of a loudspeaker's performance. This technique allowed engineers to measure the frequency response of a loudspeaker in anechoic conditions, even in non-anechoic environments.

Long founded the company E.M. Long Associates (ELMA) in Oakland, California, which produced measurement equipment and provided consulting services based on his TDS and MLS technologies. He was a prominent figure in the Audio Engineering Society (AES) and actively contributed to the advancement of audio engineering through his research, publications, and presentations. His work remains highly influential in modern acoustic measurement and sound system design.