The first EMI Columbia Athens studio was called studio 3 (operating after 1936).
From ?? up to about 1950? recording was done with 2 microphones, at omni or directional.
One mic would be close to the singer but at 90 degrees, the other further away close to the orchestra. Leakage from each mic would add ambience reverb. This until the echo chamber was made next to the control room.
From the use of 2 mics they went to 4, up to 1955 (year not mics!).
Microphones were mostly Neumann U47. There was also Neumann KM sometimes on guitar.
Then they had 8 mics and echo chamber.
The output of each Neumann feeding each EMI RS61 low level amplifier.
Summing was done at an 8 channel in, 1 out console.
There was another console on top, an auxiliary console to feed each instrument to the echo room.
Apparently every microphone output was connected to both console inputs by splitting the cable? in parallel.
Of course everything was done live and there was no need for wearing headphones.
According to Giannakopoulos all mics after 1962 were set to cardioid polar pattern.
After 1964 the studios 1 and 2 which were being prepared started operating.
There were large sound absorbing isolating movable baffles with windows for each instrument. About 5-6 of them for each studio.
According to photo. Around the studio were wooden splays up to a height. Then there were perforated structures up to the ceiling. According to Iannis Dimitriou, technician at Columbia, roofing felt was used inside to absorber low frequencies, and other absorbing porous material for the highs.
According to photo there were pyramid like structures on the ceiling to scatter and diffuse sound waves.
The floor was wooden. There was carpet around much of the area.
The session musicians were well accustomed to studio playing controlling their dynamics and playing not loud and expressively. Loudness does not come by playing loud but by controlling the harmonic content. especially during the first years level control was done manually by gain riding. When male singers were on their low notes, correct level capture was aided by increasing sensitivity.
Typical microphone to source distance was (20-30)cm.
Manos Hatzidakis when he was director of the 3rd radio program at HRT (Hellenic Radio Television) invited for dinner some of the best engineers of the time including Stelios Gannakopoulos, Nikos Despotidis, electronic engineer Mikes Psalidas. There he asked them how could the sound quality of the 3rd program productions be improved. Some of the problem areas identified were that the recording spaces need be larger. Larger areas would help accommodate larger and tall isolating panels with windows as there were at the Columbia Athens studios.
Almost all of the above information is from conversation with Columbia engineer, Stelios Giannakopoulos. Stelios could not overemphasize how important is the quality of the source on sound, first ingredients, as it is on any area. As an example he quoted how important orchestration, arranging is. He summarized with "Εν Αρχιν Ην ο Λόγος", and λόγος with all its meaning, reason, logic, cause, sound.
Reference: Conversation with Stelios Giannakopoulos on April 22 2017.
