Digital Sound on Super 8, Is It possible ?

[Rob Young]

Hi Steve. I remember having similar conversations with a fellow collector 20 odd years ago. The notion of getting a DTS time code onto the magnetic stripe such that a DTS reader could identify and use it was intriguing, but at that point everything home computing and software wise was still rather limiting, so I forgot about the whole thing.

I would love it if you could achieve this. I guess the problem still remains as to how practical it is to get a DTS time code onto a super 8 magnetic stripe, whether this is doable at all? Let us know how you get on.

[Lindsay Morris]

For those NOT familiar with 35mm film & DTS track.

The DTS track on a 35mm print lies alongside the Optical Stereo tracks and its just a series of dots and dashes...sort of best way to describe it I can think of.
That is read by the DTS scanner which then syncs the audio on the DTS disc/s inserted into the scanner to the exact frame of fim.
Its so quick that should you chop a few feet of image out due to damage etc the the DTS reader knows exactly whats been removed and almost instantly matches the audio to the image.

Just HOW one would capture that Time Code as added to a 35mm print is anyones guess...you might have the DTS disc's but they aint any good without that critical Time Code.

BTW 35mm film runs through a machine at 90 feet per minute which is way faster than 16mm film and one hell of a lot faster than Super 8. However having said that good quality reel to reel machines such as Akai and others give VG audio response at 3 & 3/4 IPS past the capstan.
So good striping is the answer.
Lindsay

[Ed Gordon]

Also see: 35mm cinema film and digital audio

[Rob Young]

“Just HOW one would capture that Time Code as added to a 35mm print is anyones guess...“

Exactly, Lindsay. Therein lies the problem / challenge.

The DTS playback requires that digital time code to sync with the print. Is there any possible way to convert that signal into something that could be recorded onto magnetic stripe and then replayed and converted back to the digital signal required…and then make sure the time code was actually in sync with the print as well.

Hmmm…quite a challenge!

[Osi Osgood]

Ed, thank you for those images on 35mm, close up. Amazing as to how much technology has advanced over time. I remember being awed by microscopic blowups of a record groove, and how all those minute "canyons" in the vynl produced sound merely by the "vibrations" produced. Then, I found the early "selecta-vision" video discs ( out there in the early days of laserdisc ) had not just audio, but we're able to capture video as well. For some odd reason, a laserdisc made more sense than a vynl video disc. Then came these "upgrades" to the reproduction of sound. Wonderful!

[Joerg Polzfusz]

You could probably do an approach similar to this one (in the „record“-step, only feeding track #4 with the Timecode into the projector so that the timecode gets recorded onto the magnetic soundtrack. Later, in the „play“-step, you’ll sync the reaper software to the timecode from the projector…).
https://www.reddit.com/r/audioengine...digital_audio/

[Steve Lee]

How I propose to do this is like so.
I will use the Disney excerpt of The Jungle Book as I have a couple of copies of this. This is perfect as it hasn't been edited from the original film, so the soundtrack on the DVD should match without editing.
I will extract the multi track soundtrack from the DVD using mkvextract software. This allows for each track to be controlled individually or played back as one multi track. On this software there is a timecode generator that allows for a code to be added on a seperate track.
I will start by playing both the soundtracks from the computer and the projector simultaneously, so it is possible to control the speed and pitch from the computers version, so they both match exactly, by ear.
On the computers version I will place a pulse tone 5 seconds before the track and timecode starts. On the film leader I will count back 5sec worth of frames and mark the frame with a cross. This then can be placed in the gate ready to start the recording. I will then record just the timecode signal onto the balance track on the film.
The next step would be to record the soundtrack and the timecode onto a SD card using a WAV file format, as this can be used for multi track recordings.
Using a raspberry pi or something similar, feed the signal from the projector into this and allow this to control the timecode sync with the card reader, so that both codes match when playing.
Looking at this logically, it is no more than controlling a MP3 player with a timecode. If it is possible to make this work, Yes this would be a first for Super 8. But in the real world this is obsolete vintage technology. Things have moved on so far from the days of DTS.

[Lee Mannering]

Going back a few decades I successfully re recorded Never Ending Story at high enough level to trigger my Pro Logic surround system.
I demonstrated that to the great Mr Simmonds.
Machines were much newer then of course with higher tolerances.

A little off topic.
I fitted Digital outputs in my Eumig and Elmo GS machines so i only use the old pre amps. This is then fed into a modern Denon amp.

[Joerg Polzfusz]

Here’s a webpage with a sample of LTC (linear time code) in an audible (and recordable) form:
https://www.production-expert.com/ho...ode-101-part-1
To quote the page: „Listening to the LTC signal itself isn't the most pleasant experience as it is just a square shaped waveform operating between 960 – 2400 Hz.“
Hence it should work with S8 instead of an audio tape, too.

Data copied from the old super8data (from the backup on https://www.filmkorn.org/super8data/ to be precise):

frequency response: 40-11,000 Hz at 18 fps, magnetic sound with Eumig S 926 GL 40-13,000 Hz at 24 fps, magnetic sound with Eumig S 926 GL 50-7,000 Hz at 24 fps, optical sound with Fumeo 9119 OM 50-5,000 Hz at 24 fps, optical sound with Eumig S O&M

Drawback of this method would be that it‘s „sepdig“ - with the real soundtrack being stored in a separate digital file, requiring a separate playback device. Advantage of this method would be that the sound playback would work with any projector that supports playback of sound from the soundtrack - you would only have to put your computer between projector and the speakers.

[Ed Gordon]

Steve, here are my thoughts in comments embedded in your post.

I will use the Disney excerpt of The Jungle Book as I have a couple of copies of this. This is perfect as it hasn't been edited from the original film, so the soundtrack on the DVD should match without editing.

Comment: That sounds perfect. The only possible "gotcha" is that the excerpt itself may have been edited before put on film.

I will extract the multi track soundtrack from the DVD using mkvextract software. This allows for each track to be controlled individually or played back as one multi track. On this software there is a timecode generator that allows for a code to be added on a seperate track.

Comment: I have used Audacity to create a 6 channel (5.1) audio file from scratch. You can add as many tracks as you need. I would add a 7th track dedicated as the control track. I would then output the first 6 tracks to a file that would be played from a computer, and put the control track on the balance strip of the film. The projector's control track output would then be sent to the computer to start the audio playback

I will start by playing both the soundtracks from the computer and the projector simultaneously, so it is possible to control the speed and pitch from the computers version, so they both match exactly, by ear.
On the computers version I will place a pulse tone 5 seconds before the track and timecode starts. On the film leader I will count back 5sec worth of frames and mark the frame with a cross. This then can be placed in the gate ready to start the recording. I will then record just the timecode signal onto the balance track on the film.

Comment: That would be track #7 in my example above.

The next step would be to record the soundtrack and the timecode onto a SD card using a WAV file format, as this can be used for multi track recordings.

Comment: In my first comment, the 6 channel file I created came from a mono WAV file. The format of the final file in my case was an MKV file with the audio and video. I would recommend MKV format since you can add or remove tracks on the fly. The transfer rate on SD cards my be too slow to support AC3 audio. I extracted the Dolby Atmos audio from a movie and it was 1.3 GB alone

Using a raspberry pi or something similar, feed the signal from the projector into this and allow this to control the timecode sync with the card reader, so that both codes match when playing.
Looking at this logically, it is no more than controlling a MP3 player with a timecode. If it is possible to make this work, Yes this would be a first for Super 8. But in the real world this is obsolete vintage technology. Things have moved on so far from the days of DTS.

Comment: Yes, but in the real world nobody is interested in Film anymore, and we know that is not the case. You can do all this without film. Just buy the Bluray. However, cool projects like yours will draw more interest in film, so go for it!

[Brian Fretwell]

I once asked someone from Dolby at a demonstartiob of 25mm Dolby Digital, if the Double D symbol on the treck was ro prevent others copying the system by making the decodet shut down if it didn;t see that (copying would be a breack of trademark). He said that it wasn't but they had spacroom in the bit rate so put it in!!

[Chip Gelmini]

Good luck getting this done. I'm all for it if workable.

I must admit however the task seems impossible based on possible cost. I will also admit I got the biggest laugh over this idea in general. And most importantly no dis respect to those trying to get it done. For some reason, I just thought it was quite funny......

Now if you will all excuse me I'm going to be busy for a long time. I'm going to paint the spacing between the sprockets on all of my features in hopes that I might be able to encode Dolby Digital in that location.......

[Douglas Meltzer]

We had an earlier thread on this subject that was started by a more serious(!) Chip almost 20 years ago:

Digital Sound on Super 8?

[Chip Gelmini]

LOL. Yup I do recall asking before.....

[Rob Young]

Wow, 20 years and here we are again...lol!

To be fair, Chip, Steve is going down to the route of attempting to add a time code recoded onto the stripe, which, at least in theory is possible.

I'd love to see him succeed, just for the heck of it. It is a hobby after all.

Slightly off topic (more adventures in super 8 sound really) but I believe, was it Adam (?) that recorded the Jurassic Park 600ft using Dolby Prologic II and managed to get Prologic II 5.1 playback from it?! Not digital I know, but quite something.