In the late 1930s and 1940s, the music recording and playback industry and technologies like early record players and sound in movies exclusively utilized a monaural (mono) system. What is mono, you may ask – well, Mono involves recording and playing back audio through a single channel, regardless of the number of sounds or instruments in the recording.
By the 1960s, the production and release of records transitioned to stereo, where audio was delivered through two distinct channels, left and right.
Stereo subsequently became the prevailing standard, extending its influence to formats like cassettes and stereo playback systems and into the modern digital age. It’s worth noting that the concept of stereo was conceived in the late 19th century, and stereo technology was available in the early 20th century. Nevertheless, mono persisted for an extended period because technology companies and radio broadcasters of the time were not yet prepared to abandon their mono systems.
So meet the person responsible for this evolutionary experience: Alan Blumlein, who was given a posthumous Grammy Award for technical services to music 75 years after his death.
Alan Blumlein’s remarkable contributions to the field of electronics are evident through his 128 filed patents during his tenure at EMI. Although he worked on various aspects of transmission and communication media, such as telephone lines, television, and radar, perhaps his most significant invention is what we now recognize as stereophonic audio. His innovative method involved using two microphones for audio recording, which is still known as the Blumlein Pair and remains in use today. These microphones are of a special type known as dipole microphones, capable of capturing sound from both the front and rear directions.
Source: The Conversation
When positioned at right angles to each other, these two microphones, in combination, can capture sound from all four corners of a room. This unique approach records the direction from which the sound originates. For instance, if individuals were standing to the right and left during the recording, they would sound as if they were positioned to the right and left of the listener when the recording is played back. This innovation represented the first technique developed to capture the directional aspects of sound faithfully.
Lightbulb Moment!
Picture this: Back in the day, people flocked to the cinema for a movie night, but there was a hitch – they were stuck with just one sad little speaker for the entire gigantic screen. It’s safe to say that a solitary speaker wasn’t cutting it, and it seriously messed with the way folks enjoyed their films. Enter our hero, Alan Blumlein, who had a lightbulb moment while watching a movie in 1931. He decided to fix this audio conundrum and filed a patent for his “binaural” recording technique.
Blumlein wasn’t content with just revolutionizing the cinema experience. He also came up with a brilliant way to make his new stereo recording compatible with the good old gramophone records of the time. He devised a nifty method to capture two audio channels in a single groove on the record. It involved tracking the sound information from two needles moving in two different directions, like two friends dancing to their own beats but always at right angles (that’s a fancy term for rotated by 90 degrees). For regular mono recordings, the stylus moved from side to side, but for stereo, one stylus moved in and out diagonally, and the other did the same but with a cool 90-degree twist.
Source: The Conversation
What did all this lead to? Well, it paved the way for the first stereo recordings of the London Philharmonic Orchestra in 1933 at what we now know as the legendary Abbey Road Studios. Interestingly, even though Blumlein had unleashed this fantastic stereo tech, it took a while to catch on. Interestingly, this technology took quite a while to become widely adopted. Even as late as 30 years after its introduction, the Beatles continued to produce their LPs using the older mono recording method, which meant they were single-channel recordings.
Surprisingly, despite his remarkable innovations, Alan Blumlein’s name didn’t gain the recognition one might assume. It wasn’t until the latter half of the 20th century that his genius was truly acknowledged – we owe him for the music we are able to hear on vinyl today as well. A genius unrecognized, truly.
