The years before ...
Brüel & Kjær was known worldwide for their accurate measurement microphones
Brüel & Kjær (B&K) began producing microphones in 1945. By the early 1970s, B&K's strong presence in the measurement microphone field had become firmly established with the development of high sensitivity 1/2″ microphones.
Ole Brøsted Sørensen, a subsequent founder of DPA Microphones, used a B&K measurement microphone to record a choir ensemble that his wife was a part of
Ole let some friends in the radio business hear these recordings. At that point in time, omnidirectional microphones were not used for audio recordings, so everyone was blown away by the sound! This led to Ole recording a live transmission of a Thursday evening concert for Denmark's Radio. Sixteen
B&K measurement mics were used and the results were amazing. Reviewers, sitting at home listening from their own speakers, could clearly hear the difference and raved about the sound.
B&K started measuring (of course!) to see if they could find a correlation between the objective and subjective parameters of the sound
People said things sounded better with these measurement mics, but did it really? B&K wanted to measure that the audio quality was indeed better. So they did.
B&K built a standardized listening station and made "blind" tests with all types of individuals - ranging from professional sound experts to soldiers with hearing issues. The results showed that close to 100% of listeners thought that the B&K microphones relayed the best sound.
B&K started transforming their omnidirectional measurement mics into a pro-audio range
Ole started up a project team to ensure that the new microphones had the qualities needed to be used in the pro-audio industry. While the capsule technology was already in place, the microphone housing needed to be revamped to ensure that the microphones could survive in the often harsh environments found on tour, in recording studios and the like. Also, the microphones needed to be adjusted to use Phantom Power from the external equipment in the audio system (see infographic for more info).
After a few years of intensive work, the first pro-audio microphones from B&K were ready and launched
Four versions - the 4003, 4004, 4006 & 4007 were created to meet the needs of several types of users. Today the d:dicate™ 4006A and d:dicate™ 4007A are still going strong.