When I first walked into a Munich sound studio for dubbing and sound mixing in the seventies, there were still 20 huge machines clattering noisily in a machine room.  To stop all this machinery, an equally noisy, man big, mechanical generator had to be started up, with the only task to stop the whole gears wheel machinery, these so-called "Perfoläufer" (The German word for a Tape Payer, which could play magnetic film tapes) and then ramp up in line again to the 50 Hz mains frequency to go back into the play mode again. A very noisy affair. The format of the perforation and the width of the magnetic stripe was equal to the usual film format of 16 and 35 mm films. The individual tapes contained all recordings of speech, sounds, music and atmospheres that were considered for the respective film mixing necessary and came from the editing room. At the cutting tables these recordings got ordered, synchronized and mounted to the film accordingly.

   During the sound mixing thereafter than ran all these required tapes for the first time simultaneously together, which  caused occasionally surprises, because on a cutting table you could usually only here two tapes with the film print.  The sound engineer was in the rerecording room (see picture above from the 80) with its mixing console and could operate from there all the tape players.  The audio signals of the individual tape players were placed on the inputs of the mixing console and passed through its various channels, so that the rerecording engineer could adjust each signal to it's optimum quality or purpose for the project. The mixed signal in turn was recorded on a magnetic film with  a recording camera. This was only a magnetic film player equipped with a recording unit.

   The mixing technique used could be best described as a "edit-mix technique". But it was a very sportsmanlike technique, because the automation memory was the mind of the sound engineer, the automation tools were his finger and the  error correction of its automation was left to his ears. The usual procedure was to listen to a scene, make adjustments and corrections to the signals and then to practice the dynamic processes until you master the necessary timing and then again repeat the whole pattern flawlessly during the recording. For a perfect punch in, into an existing recording at a scene transition or within a scene, in case of failure to repeat a flawless pattern with your fingers, you had to remember all the console settings up to this point in time and bring all active control devises of the console back into this position, move with all your machinery up to this point in time and punch into your existing recording precisely.

      At those times, this was one of the most modern sound studios, because you could not only make a "punch in" into a recording, no -  you even could "punch out" of a existing recording without an crackle. Among the traditions of this period, however, are the stories of how you recorded the mix on optical sound, before the times of magnetic film tape. Since there was no way to punch in or out at all. Those mixing techniques could have been called the "drill-drill-drill-mixing technique".  The sound engineer could only practice, practice, practice ... until he finally reached a point that  he could dare to expose an optical sound negative,  but in case of a blunder another negative had to be exposed. What an effort of skill, time and materials?

     Given this history, it seems like a miracle that we can comfortably run today all these works on a home computer or laptop.