David E. Blackmer (11 January 1927-21 March 2002) was an American audio electronics engineer, most famous as the inventor of the DBX noise reduction system and founder of dbx, Inc.
As well as audio noise reduction, Blackmer worked on extending the frequency response of audio electronics beyond the conventionally-accepted audible range of 20 kHz. He also published research on the value of ultrasonic frequencies in sound reproduction, claiming that the time resolution of human hearing is 5 microseconds or better – which would correspond to a frequency of 200 kHz, requiring audio equipment ideally to have a flat response to that frequency.
David formed Earthworks with his passion focused on inventing new technologies for microphones, preamplifiers and monitor speakers.
Here’s the story of how Earthworks Microphones came to be, as told by the folks at Earthworks to Audio Times
“Earthworks microphones and preamps all descend from a philosophy reflective of our roots as a scientific measurement device manufacturer. As such, we strive to maintain an identity as a manufacturer of precision equipment capable of reproducing audio with maximum consistency & accuracy throughout a microphones polar pattern and preamps operating range.
“Earthworks Audio was originally founded to design and manufacture audiophile loudspeakers. David Blackmer’s goal when starting the company was to make the best sounding speakers on the planet. His enjoyment of music was a true passion. His philosophy to achieve this goal involved many principals in science and art. When the journey began, David used measurement tools that were accepted to be the world standard. After the first few steps he realized that the measurements he was getting were not as good as he believed they could be. He analyzed these tools carefully and realized that new standards would be necessary if he were to even come close to achieving the results he knew were possible.
“The first tool he designed to this new standard was an omnidirectional microphone. This led to the manufacture of the OM1. David now thought that he could get back to designing his “dream” loudspeaker. His colleagues, however, persuaded him to design other microphones and preamplifiers. These products would soon set a new world standard for realism in the art of recording music. While the years passed and these new microphones and preamplifiers were being manufactured, David constantly worked on his goal of designing the best sounding loudspeaker for true audiophiles. He assembled and groomed a team of real world oriented people with the same goals and dedication to achieving these goals. Created in beautiful hand selected solid Cherry panels, the Earthworks Sigma 6.2 was the end result of many years of research.
“While we no longer make the loudspeakers, the scientific and artistic principles that David first envisioned when the journey began can still be seen in our microphones. Our microphones are able to capture and reproduce a soundstage so deep and wide that if you close your eyes you can “see” the music in front of you. Microphones that present transients so smooth you can feel the rosin on the bow as it plays across the violin. The unique design allows the timbre of all instruments to be translated so accurately that your “sixth” sense creates their presence right in front of you.
Approach to Microphone Design
“Acknowledging that only small diaphragm condenser microphones were the only technology available capable of the precision his specifications required (extremely short diaphragm settling times to achieve near ideal transient and impulse response characteristics), David Blackmer’s philosophy regarding time domain precision has been the guiding principal behind all Earthworks microphone designs since.
“A very wide bandwidth transducer ( e.g. from 4Hz-50kHz in our QTC50) with extremely flat frequency response, and a minimal phase response guarantees that these time domain conditions are met. Even our narrower band (20Hz – 20kHz) offerings maintain the same time domain response, but a lessened ability to precisely capture extremely fast transients. Equally as critical is the need to make sure Earthworks products are phase and time coherent across a nearly textbook perfect polar pattern. This is achieved without the traditional EQ techniques used by other manufacturers, so our polar patterns do not suffer due to our efforts to make ruler flat responses in our directional microphones. At Earthworks we use our understanding of how time and frequency are interrelated by impulse to drive our design philosophy. The results are microphones which are both phase and time coherent, which results in a marked audible improvement in sound quality both in clarity and accuracy.
“Earthworks microphones are always designed with form and function in mind as complementary elements. For example, the best way to accomplish the goal of minimizing microphone body reflections and interference was to maximize distance and minimize area’s immediately behind the microphone capsule. The very recognizable shape of our extended frequency response M, QTC, SR and TC Series microphones is because of this principle. Very similar in principal to how the shape of a stealth aircraft is used to minimize its radar cross section, Earthworks microphones are designed to minimize their acoustic cross section.”
“Another microphone that takes form and function to a new level is our FlexWand Series. This Series includes 4.7 and 7 foot integrated microphone systems, which have a 30kHz microphone, mic stand and boom in a single unit. The XLR is at the base of the FlexWand, so no cables or wires are visible above floor level. When the microphone needs to look as clean as it sounds, the FlexWand provides an option in which one doesn’t have to sacrifice sound quality for appearance.
“Hand built, hand tuned and hand tested in our Milford, New Hampshire facility, Earthworks microphones are designed and manufactured in house. Our microphone bodies are predominantly machined out of solid bars of stainless steel. Our mil spec circuit boards are encased in a special polymer epoxy. In fact -except for the microphone capsule tip, Earthworks microphones are completely sealed. The result is a microphone that can be subjected to environmental extremes, maintain specification and can be offered with a 15 year warranty.
“Earthworks products functionality is constantly being expanded by users all over the world. Many product developments have occurred because of user feedback to our engineers. The PM40 PianoMic system for example takes full advantage of our QTC40 omnidirectional capsule, and once modified for use in a random incident sound field (inside a piano) and installed on a extendable bar designed for seamless, results in a nearly invisible closed lid miking applications. Users will attain real live sound reproduction without hot spotting and with maximum sound isolation with the piano lid down.
“Our first ever handheld vocal condenser microphone, the SR40V, places Earthworks technology into a familiar form factor. Most recently we have adapted the 30hz-40khz SR40v to be attached to popular wireless transmitters made by Shure, Lectrosonics and Line 6 so performers can experience the increased clarity, gain and pattern control of Earthworks technology untethered. New uncompressed digital wireless technology further helps make the sonic advantages of our WL40v very obvious to all who wish for greater clarity in a vocal handheld microphone.
“We are constantly evaluating and innovating new uses of our fast, wide frequency, phase and time coherent products and have the appreciation of artists, engineers, and scientists worldwide. Earthworks products should appeal to those who seek to capture waves as they appear naturally.
“We welcome user input and will in fact custom design products for specific applications not served by our already broad Earthworks Audio product line. Since 1995 we have been at the audio community’s service and strive to never diminish our reputation by making any product not in comportment with the high standards set by our founder.”