History Automixer

dan dugan s first automixers

dan dugan showed first adaptive threshold automatic microphone mixing system in 1974 @ 49th audio engineering society (aes) meeting in new york, , granted patent control apparatus sound reinforcement systems sensed ambient sound level in environment of theater control each microphone s individual level. in 1976, dugan granted patent automatic microphone mixing process whereby total gain of system remains constant. began manufacturing first automixer system, model a, based on 2 patents. dugan built 60 units, first, hand-assembled 1 taken bell labs installed in conference room harvey fletcher. algorithm simple , effective: each individual input channel attenuated amount, in db, equal difference, in db, between channel’s level , sum of channel levels. dugan licensed system altec released several automixer models including 1674a, -b , -c series , 1684a, focusing on speech applications. (the 1684a became electrovoice product , administered commercial division.) earliest altec product implementation regarded inferior within commercial audio contractor industry, , other manufacturers began design own automixer products.

in 1978, richard w. peters of industrial research products (irp) granted improvement patent entitled priority mixer control . irp released voice-matic series of 4 × 1 , 8 × 1 automatic mixers using dynamic threshold sensing weighed combination of amplitude , history of signal determine channel access. master output attenuated @ rate of 3 db every doubling of nom. master output reduction solution used yamaha pro audio 2 decades later in dme series of digital signal processing (dsp) products, incorporating automixer function otherwise 8- or 16-channel noise gate.

eugene campbell , terrance whittemore of colorado granted patent in 1982 automatic microphone mixing algorithm allowed musical performance mixing not dominated loudest vocalist or instrumentalist.

graphic user interface digital automixer uses gain-sharing algorithm. controls include threshold, depth, polarity inversion , muting each input, volume controls 4 inputs, 4 individual outputs , full mix output

stephen d. julstrom of shure brothers, inc. (evanston, illinois) granted patent in 1987 teleconferencing system used special directionally gated microphones mixed automatically , sent distant party via telephone line. return signal distant party compared in strength local mix determine party prominent in overall mix. interrupting party given priority. 4 years later, shure introduce ams4000 , ams8000 automixers sound reinforcement; mixers required use of special directional condenser microphones of shure ams series.

in 1985 innovative electronic designs (ied) introduced circuit card frame-based auto mic mixing system featuring combine-separate function , programmable gain control (pgc) modules. combine-separate functionality useful ballroom applications movable partitions permit portions or of room used 1 program or multiple programs. pgc modules compensate individual mic channel gain soft-spoken or loud presenters, boosting or cutting channel gain, respectively.

at 87th aes convention in 1989, dugan introduced idea of using automixer inserted within target channels on professional audio mixer. each microphone s signal interrupted inside channel strip , sent variable gain circuit contained within automixer. signal returned mixer @ level consistent dugan algorithm. became dugan model d automixer.

in 1991, dugan s patent expired. competing manufacturers began bring dugan algorithm directly product designs. in 1993, travis m. sims, jr. of lectrosonics (rio rancho, new mexico) granted patent sound system rate controlled, variable attenuation of microphone inputs, including dugan algorithm loudspeaker zone attenuation when in close proximity active microphone. loudspeaker zone part of patent cited 1985 patent proportional amplification eugene r. griffith, jr. of lvw systems of colorado springs, commercial audio contractor. in 1995, sims , lectrosonics gained patent adaptive proportional gain audio mixing system incorporated number of ideas including dugan algorithm maintaining constant total gain of inputs.

in 1996, dugan came out model d-1, speech-only economy model did not offer music system of model d.

in 1997, john h. roberts of peavey electronics granted patent automatic mixer priority circuit, enabling hierarchy of logic weighting allowed selected signals push forward in mix when in use, while still maintaining useful constant unity, gain-sharing relationship first described dugan. hierarchy enabled host, moderator or chairperson speak on other participants , retain control of discussion. peavey s architectural acoustics division used 3 levels of hierarchy in 1998 automix 2 product, placing first- , second-most influentially weighted sources @ inputs 1 , 2, respectively.

dan dugan licensed system protech audio (indian lake, new york) in 1997, yielding protech 2000 model series.

in 2004, first standard audio mixer incorporating eight-channel automixer section released peavey in sanctuary series, , in 2006 similar hp-w introduced crest. both mixers aimed @ house of worship market, adding functions ease process of audio mixing religious organizations.

in 2007, mark w. gilbert , gregory h. canfield of shure (niles, illinois) granted patent digital microphone automixer system used time of arrival main decision-making criteria.

generations of dugan s insertable automixers

in february 2011, dugan announced automixer card plug in accessory slot of yamaha digital mixing console such ls-9, m7cl or pm-5d. card, dugan-my16, can mix 16 channels of microphone inputs @ 44.1–48 khz or 8 channels @ 88.2–96 khz sampling rates. channels automixed assigned in mixer s graphic user interface, , can controlled common web browser interface affecting dugan-my16 card, allowing remote control ipad, touchscreen computer or laptop on wireless network.