The founder of "Audio Research Laboratory" - Prof. Ivan Valtchev (1927 - 2011), graduated the State Polytechnic - Sofia in 1950. He worked as a designer, technologist and researcher of
electroacoustic transducers in the Weak Current Plant, Sofia and the Research Institute of Cinematography. In 1975 became Associate Professor at the State Polytechnic; then, since 1984 is professor of Electroacoustics (electroacoustic transducers) with the Technical University, Sofia. Retired at 1993 and founded the "Audio Research Laboratory".

   Throughout his active life, he developed electrodynamic speakers and solved technological problems related to their production.

   He created his first high frequency loudspeaker far ago in 1968. He has developed and implemented in production 12 models of ribbon loudspeakers, for approximately 40 years.
In this not so short time the construction and technology of ribbon loudspeakers were improved.

   Professor Ivan Valchev was president of the Department of Acoustics at the Bulgarian Federation of Scientific Societies and president of the Bulgarian section of Audio Engineering Society, USA.

   Since 2012 Audio Research Laboratory is running again production of legendary ribbon loudspeakers NdRL41-MkII and NdRL81-MkII, which are distributed all over the world.
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