Back in the day, did they ever think of using film (as in for pictures) for recording sound? You could have some sort of setup like an oscilliscope without a timebase with fast decaying phosphors (dual trace for stereo), which was projected onto the film. If the speed of the film is high enough you could achieve a bandwidth up to 20Khz. The film would then contain the waveform of the audio as a streak in the shape of the waveform down the film. This way, the sound would take MUCH longer to degrade compared to magnetic tapes, and you would have bandwidth from pretty much DC to 20Khz or whatever your desired top end is. Old recordings could have been restored to 95% of their original quality of they archived them this way probably
If you ran the film by about 2m per second (pretty fast), that would give you 0.1mm to store a single cycle of a 20Khz wave but film can store quite a lot of detail so this might not be so bad. You would get through film quicker than if you were recording a motion picture but albums and stuff aren't generally as long as a film and you would go straight from tape to film without cutting and splicing so you would waste less too
Just an interesting idea I had
(I realise that they used to have the audio track down the side of films but I'm talking about the exclusive use of film to store audio)
If you ran the film by about 2m per second (pretty fast), that would give you 0.1mm to store a single cycle of a 20Khz wave but film can store quite a lot of detail so this might not be so bad. You would get through film quicker than if you were recording a motion picture but albums and stuff aren't generally as long as a film and you would go straight from tape to film without cutting and splicing so you would waste less too
Just an interesting idea I had
(I realise that they used to have the audio track down the side of films but I'm talking about the exclusive use of film to store audio)
bigwill: " ... did they ever think of using film (as in for pictures) for recording sound? You could have some sort of setup like an oscilliscope without a timebase with fast decaying phosphors (dual trace for stereo) ... "
Yes, pretty good ideas here:
The "Time Base" does exist ... the sprocket speed of the projector = its not very stable, but that's what was used on movies for a long time = about 25 sprocket click per second, so there wasn't a very good bass response = 25 Htz.
I have seen several "conversions" of old projectors to "free running" and speed controlling the drive motor with governor and timed strob lights used project the images ...
The audio track on "old" film is a series of visual images, several milliseconds of sound per frame, very like the response pattern you might see on the vertical axis display of a 'scope.
Yes, pretty good ideas here:
The "Time Base" does exist ... the sprocket speed of the projector = its not very stable, but that's what was used on movies for a long time = about 25 sprocket click per second, so there wasn't a very good bass response = 25 Htz.
I have seen several "conversions" of old projectors to "free running" and speed controlling the drive motor with governor and timed strob lights used project the images ...
The audio track on "old" film is a series of visual images, several milliseconds of sound per frame, very like the response pattern you might see on the vertical axis display of a 'scope.
Blumlein explored this in 1935 -- in his original patent -- according to Norman W. Green who gave a presentation to the AES on sound and pictures in 1988.
There is also an AES paper discussing the Haus des Rundfunks in Berlin, etc., etc. Fascinating stuff as I find a lot of the AES stuff to be (and well worth the membership.)
There is also an AES paper discussing the Haus des Rundfunks in Berlin, etc., etc. Fascinating stuff as I find a lot of the AES stuff to be (and well worth the membership.)
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