# Harry F. Olson

Dr Harry Ferdinand Olson, E.E., Ph.D. (December 28, 1901 – April 1, 1982) was a prominent engineer and inventor with RCA Victor, the Acoustic Research Director of RCA Laboratories, Princeton, and a pioneer in the field of 20th century acoustical engineering notably in the fields of high-fidelity, digital music synthesis, microphones, loudspeakers, acoustics, radar, submarine communication, magnetic tape and noise reduction.
Olson wrote ten books including Dynamical Analogies, on electrical-mechanical-acoustical analogies, and had over one hundred patents.

## Biography

Harry F. Olson was born in Mount Pleasant, Iowa, to Swedish immigrant parents. Technically inclined from an early age, he built and flew model airplanes, constructed a steam engine and invented a wood-fired boiler that drove a 100-volt DC generator. Olson designed and built an amateur radio transmitter, gaining enough proficiency to be granted an operator's license. Olson went on to earn a bachelor's degree in electrical engineering from the University of Iowa then continued to earn a master's degree with a thesis on acoustic wave filters in solids and a doctorate in physics, working with polarization of resonance radiation in mercury.
Immediately after completing his course of study in 1928, Olson moved to New Jersey to work for RCA Laboratories. Olson would remain at RCA for almost four decades.
Olson had a continuing interest in music, acoustics, and sound reproduction, and, by 1934, he was placed in charge of acoustical research at RCA. At RCA, Olson worked on a wide range of projects, which included developing microphones for the broadcasting and motion picture industries, improving loudspeakers, and making significant contributions to magnetic tape recording.
Like many engineers of the World War II generation, Olson also made significant contributions to military technology as well, particularly to the fields of underwater sound and anti-submarine warfare.
After the war Olson, along with Herbert Belar, developed the first modern electronic synthesizer. Equipped with electron tubes, the Mark II Sound Synthesizer was used to compose music, which was recorded and sold to the public.
A prolific inventor and engineer, Olson was awarded more than 100 patents for the various types of microphones (including the widely used 44- and 77-series), cardioid (directional) microphones, loudspeaker baffles, air-suspension loudspeakers, isobaric loudspeakers, early video recording equipment, audio recording equipment, phonograph pickups, underwater sound equipment, noise reduction, sound technology in motion-pictures, and public-address systems he developed. He also authored 135 articles and ten books including an interdisciplinary text charting the dynamical analogies between electrical, acoustical and mechanical systems.
In 1949, Olson was honored by being the first recipient of the Audio Engineering Society's John H. Potts Memorial Award, an award program which was later renamed the gold medal. In 1953-4 Olson served as president of the Acoustical Society of America, which awarded him the very first Silver Medal in Engineering Acoustics in 1974 and the Gold Medal in 1981. He won the IEEE Lamme Medal in 1970, was elected to the National Academy of Sciences in 1959, and was the recipient of many honorary degrees during his lifetime.
Olson retired from RCA in 1967, continuing as a consultant for RCA Laboratories.

## High Fidelity Demonstration

Shortly after World War II, Dr. Olson conducted an experiment, now considered a classic, to determine the preferred bandwidth for the reproduction of music. Previous experimenters had found that listeners seemed to prefer a high-frequency cutoff of 5000 Hz for reproduced music. Dr. Olson suspected that this was likely due to imperfections in the sound, especially in the higher frequencies, as reproduced by equipment in common use at the time. These imperfections included clicks and pops (from 78 rpm recordings), added noise (from AM radio broadcast static), hiss and harmonic distortion (from amplifier circuits), and non linear frequency response from primitive loudspeaker designs. If the sound was free of these problems, he reasoned, listeners would prefer full frequency reproduction.
In his experiment, he set up a room which was divided diagonally by a visually opaque but acoustically transparent screen. The screen incorporated a concealed low-pass acoustical filter having an upper frequency cutoff of 5000 Hz. This filter could be opened or closed, allowing either the full range of frequencies to pass or the range only below 5000 Hz. At first, a small orchestra sat and performed on one side of the screen, while a group of test subjects sat on the other and listened. The listeners were asked to select their preference between two conditions: full bandwidth or restricted bandwidth. There was overwhelming preference in favor of the full bandwidth. Next, the orchestra was replaced with a sound-reproduction system with loudspeakers positioned behind the screen instead. When the sound system was free of distortion, the listeners preferred the full bandwidth. But when he introduced small amounts of nonlinear distortion, the subjects preferred a restricted bandwidth, thus demonstrating clearly the importance of high quality in audio systems.
As a result of this experiment and the work of others, such as Avery Fisher and later Edgar Villchur, high fidelity sound recording, transmission, and reproduction equipment saw increased investment, development, and public acceptance in the following decades. The design and manufacture of everything from microphones, to tape recorders, vinyl records, amplifiers, and loudspeakers were impacted.

## Influence on High-Quality Modern PA Systems

The Grateful Dead's early sound engineering team, led by Owsley Stanley and Dan Healy, considered Harry Olson's 1957 book "Acoustical Engineering" the Dead's "bible" on building the Wall of Sound (Grateful Dead), the first touring sound system that allowed a band to actually hear themselves and have the audience hear what the band was hearing on stage. The band made copies of the book for all of the Dead's sound crew.
The Wall of Sound influenced all modern high-quality PA systems for live music.

## Personal life

Harry F. Olson was born in Mt. Pleasant, Iowa, on December 18, 1901. He was the first of two children. His parents were Swedish immigrants.
Olson married Lorene Johnson of Morris, Illinois in 1935. Both his mother and his wife were talented amateur artists — Lorene's paintings were displayed in Olson's RCA office for many years. Olson died at Princeton Medical Center in Princeton, New Jersey on April 1, 1982, at the age of 80.

## Awards and honors

| Year | Honor or Award |
| 1940 | The Modern Pioneer Award of the National Association of Manufacturers |
| 1952 | The John H. Potts Medal of the Audio Engineering Society |
| 1955 | The Samuel L. Warner Medal of the Society of Motion Picture and Television Engineers |
| 1956 | The John Scott Medal of the City of Philadelphia |
| 1956 | The Achievement Award of the IRE Professional Group on Audio |
| 1963 | The John Ericsson Medal of the American Society of Swedish Engineers |
| 1965 | The Emile Berliner Award of the Audio Engineering Society |
| 1967 | The Institute of Electrical and Electronics Engineers' Mervin J. Kelly Medal |
| 1969 | The Institute of Electrical and Electronics Engineers' Consumer Electronics Award |
| 1970 | The Institute of Electrical and Electronics Engineers' Lamme Medal |
| 1974 | The Acoustical Society of America's first silver medal in engineering acoustics |
| 1981 | The Acoustical Society of America's Gold Medal |

## Patents

| Year | Patent Description | Patent Number |
| 1931 | Acoustic Device For Sound Pick-up (Ellipsoid Microphone) | 1,814,357 |
| 1932 | Apparatus for Converting Sound Vibrations Into Electrical Variations (First Practical Ribbon Microphone) | 1,885,001 |
| 1932 | System Responsive to The Energy Flow of Sound Waves (Pressure and Velocity Sound Level Meter) | 1,892,644 |
| 1932 | Sound Pick-Up Device (Unidirectional Cardioid Microphone) | 1,892,645 |
| 1933 | System For the Conversion and Transfer Of Energy (Condenser Microphone Step-Up Transformer With A Remote Preamplifier.) | 1,897,732 |
| 1934 | Acoustic Device (Loudspeaker Horn) | 1,984,542 |
| 1935 | Loud Speaker and Method of Propagating Sound (Passive Radiator Loud Speaker) | 1,988,250 |
| 1935 | Acoustic Device (Double Voice Coil Loudspeaker) | 2,007,748 |
| 1936 | Electroacoustical Device (Ribbon Telephone Microphone/Speaker) | 2,064,316 |
| 1937 | Sound Reproducing Apparatus (Multi-Cellular Horn) | 2,102,212 |
| 1937 | Acoustical Device (Small Portable Closed Back Ribbon Microphone) | 2,102,736 |
| 1938 | Microphone | 2,113,219 |
| 1938 | Microphone And Circuit (Microphone Mixer By Verifying Field Coil Strength) | 2,119,345 |
| 1940 | Loud-Speaker (Multiple Flare Horn) | 2,203,875 |
| 1940 | Loud-Speaker (Hybrid Bass-Horn/Bass-Reflex Design) | 2,224,919 |
| 1941 | Electroacoustical Apparatus (Line Microphone "Shotgun Microphone") | 2,228,886 |
| 1941 | Acoustical Apparatus (Woofer Surround) | 2,234,007 |
| 1942 | Signal Translating Apparatus (Multiple Co-Axial Loudspeaker Designs) | 2,269,284 |
| 1942 | Electroacoustical Apparatus (Design of the RCA 77 Ribbon Microphone) | 2,271,988 |
| 1942 | Radio Remote Control System (Using Different Frequencies of Sound) | 2,293,166 |
| 1942 | Electroacoustical Apparatus (Line Array Microphone) | 2,299,342 |
| 1945 | Signal Translating Apparatus (Sub-Aqueous Submarine Microphone) | 2,390,847 |
| 1947 | Magnetostrictive Signal Translating Apparatus (Rugged Sub-Aqueous Submarine Microphone) | 2,414,699 |
| 1947 | Signal Translating Apparatus (Sub-Aqueous Submarine Pressure Compensated Speaker) | 2,429,104 |
| 1949 | Signal Transmission and Receiving Apparatus (Ultrasonically Power Wireless Earphone) | 2,461,344 |
| 1949 | Air Suspension Loudspeaker | 2,490,466 |
| 1950 | Synthetic Reverberation System | 2,493,638 |
| 1950 | Diffraction Type Sound Absorber (Suspended) | 2,502,016 |
| 1950 | Diffraction Type Sound Absorber Covered By A Membrane | 2,502,018 |
| 1950 | Diffraction Type Sound Absorber With Complementary Fitting Portions | 2,502,019 |
| 1950 | Diffraction Type Sound Absorber With Fiberglass Walls (Cylinder) | 2,502,019 |
| 1950 | Single Element, Unidirectional, Dynamic Microphone (With Pattern Control) | 2,512,467 |
| 1950 | Feedback Controller System For Recording Cutters And the Like (Phonograph Recording Lathe) | 2,516,338 |
| 1951 | Directional Microphone (Coincident Pair Of Ribbon Microphones With Horizontal Pattern Control) | 2,539,671 |
| 1951 | Coaxial Dual-Unit Electrodynamic Loud-Speaker (Improved Version) | 2,539,672 |
| 1951 | Transformerless Audio Output System (Tube Amplifier) | 2,548,235 |
| 1951 | Means For Improving The Sensitivity And The Response Characteristics Of Velocity Microphones | 2.566,039 |
| 1951 | Line Type Pressure Responsive Microphone | 2566,094 |
| 1951 | Velocity Type Microphone (Acoustic High Frequency Equalizer | 2,572,376 |
| 1953 | Suspension System For Dynamic Microphones | 2,628,289 |
| 1953 | Distortion Analyzing Apparatus (Improvement) | 2,629,000 |
| 1953 | Second Order Gradient Directional Microphone | 2,640,110 |
| 1953 | Portable Radio With A Bass-Reflex Cabinet | 2,642,948 |
| 1953 | Noise Discrimination System | 2,645,648 |
| 1953 | Cabinet For Sound Translating Apparatus | 2,649,164 |
| 1953 | Multisection Acoustic Filter (Filtering Out Frequencies above 5,000 Hz) | 2,656,004 |
| 1954 | Uniaxial Microphone | 2,680,787 |
| 1954 | Noise Reduction System | 2,686,296 |
| 1954 | Sound Translating Apparatus (Second Speaker Inside The Cabinet) | 2,688,373 |
| 1954 | Coaxial, Dual Unit, Electrodynamic Loud-Speaker (Improved Magnetic Structure) | 2,699,472 |
| 1955 | Velocity Microphone (Improved Magnetic Structure) | 2,699,474 |
| 1955 | Dynamic Microphone (Compact Design) | 2,718,272 |
| 1956 | Unidirectional Microphone (Low Cost Ribbon Design) | 2,751,441 |
| 1956 | Acoustical Resistance For Pressure Type Microphones | 2,773,130 |
| 1957 | Methods Of Restoring Phonograph Records (Re-synthesizing The Recording) | 2,808,466 |
| 1957 | Transducer With Fluid Filled Diaphragm Suspension | 2,814,353 |
| 1957 | Loudspeaker Structure (Sculpted Cone For High Frequency Pattern Control) | 2,825,823 |
| 1958 | Combination Chassis And Loudspeaker | 2,838,607 |
| 1958 | Directional Microphone (Using Two Microphones To Increase Directivity) | 2,854,511 |
| 1958 | Noise Discriminator, Threshold Type | 2,645,684 |
| 1958 | Music Synthesizer (Electronic) | 2,855,816 |
| 1958 | Wide Range Dynamic Phonograph Pickup | 2,858,375 |
| 1959 | Acoustic Apparatus (Improved Acoustic Labyrinth) | 2,870,856 |
| 1959 | Signal Frequency Change Detector | 2,918,667 |
| 1960 | Vibration Control Apparatus | 2,964,272 |
| 1961 | Apparatus For Speech Analysis and Printer Control Mechanisms | 2,971,057 |
| 1961 | Electronic Sound Absorber | 2,983,790 |
| 1961 | Directional Electrostatic Microphone | 3,007,012 |
| 1961 | Music Composing Machine | 3,007,362 |
| 1963 | Stereophonic Loudspeaker | 3,104,729 |
| 1968 | Voiced Sound Fundamental Frequency Detector | 3,400,215 |