The Altec-Lansing Model 19-MR3: The Loudspeaker That Never Was Audiophile Nirvana Posted on April 30, 2020 by Jim LansingMarch 3, 2022 The Altec-Lansing M500 Maestro is a largely lost and forgotten loudspeaker, but it is, perhaps, the best the company ever built. It arrived in the final days of Altec-Lansing, Inc., and production was cut short due to the sale of …