8mm Forum: Using DVD/LaserDisc Audio for Super 8 Stereo

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Posted by Osi Osgood (Member # 424) on November 11, 2017, 11:26 AM:

Since I'm all about audio quality for super 8 (today, it's on my mind) ...

Which is the better for doing a recording for? I'm not talking about audio quality per se, but which is easier to record an audio track off of for super 8 mag stripe?

I don't know this topic too well, but I'm betting that whichever one has the same speed as super 8 sound (24 fps), would be the obvious choice. [Smile]

Posted by Douglas Meltzer (Member # 28) on November 11, 2017, 02:24 PM:

Osi,

I have no experience with laserdiscs. I would think a Blu-ray disc would have the best audio, depending on the source material. Is that an option for you?

Doug

Posted by Mike Spice (Member # 5957) on November 11, 2017, 03:31 PM:

If I understand your post, you want to record from a dvd or laser disc or blu ray, to then put on super 8 stripe?

Given the narrow tape on super 8 I don't think you will hear a difference in the source once it is on mag stripe, and of course, you will have to record to super 8 mag using analogue unbalanced connection, so either way, just go for the easiest, but make the best possible recording using good control of the levels being recorded. .

Personally I would record in to audacity, do any top and tailing and normalising required, and from there to super 8 mag stripe.

Posted by Winbert Hutahaean (Member # 58) on November 11, 2017, 05:01 PM:

Find any sound with dolby surround encoded already. This means if you can make the stereo sound (L + R) has a balanced ouput, you can hook up the projector to a surround processor and have spatial surround presentation.

The surround effect is hidden between the L + R output. But since every projector has imbalanced output between main and balance track, you need to work with this situation.

The digital surround is an old-fashioned method, but that is the only way available to super 8mm unless you are going to use a Pedro Box and hook it up with a Bluray player for an actual 8.1 surround sound.

Cheers,

Posted by Bill Brandenstein (Member # 892) on November 17, 2017, 12:23 AM:

Another great question, Osi, and you already have some great answers. Let me add a little bit to this.

Which format is easier is entirely up to the gear and workflow you want to try. Any video format is useful. You already know that you can record through analog cables to your Super 8 gear; better is to try to extract/create digital data in a computer or recording device, then transferring. The latter gives the most control of course (hence Mike's advice), but makes the workflow much, much more complex. The benefit, however, is precise results and the possibility of exact synchronization.

So you have several considerations:
What gear you have, including computer audio and software
If you have any sort of synchronization control to regulate the film re-recording speed, or if it's guesswork
Whether or not the audio is adequately usable directly from the video device
Etc

So, for your encouragement, I can tell you that I've re-recorded faulty Super 8 soundtracks from Laserdisc, DVD, and even VHS. You'd never be able to tell now by just listening to the film sound which is which.

Posted by Brad Miller (Member # 2) on November 17, 2017, 03:36 PM:

Most blurays have remastered audio for tiny tv speakers and "home theater in a box" type of systems. In my opinion, and many others, this destroys the original audio mix.

This silly remixing practice wasn't happening with DVDs. The DVD, even though it has AC3 compression, is much lower compression than theatrical SRD Dolby Digital soundtracks and will be a better source than a bluray.

VHS HI-FI tends to have issues with buzzing during modulation so that would definitely be my last recommendation.

LaserDisc is going to have really good quality audio, but back in the day of VHS and LaserDisc I found reel changes on the video sometimes had extra frames missing that were in the Derann prints, and also sometimes had extra frames that were not in the Derann prints. Basically every reel A and reel B is a potential point for sync to suddenly be off by a frame or more PLUS the side flip point of the LaserDiscs. This just means more unnecessary work. I found this wasn't near as big of an issue using a DVD as a source.

So the straightforward answer is, get a DVD and choose the 2 channel stream. Try to avoid the 5.1 mix. By choosing the 2 channel stream, you are getting the exact mix that was Lt, Rt from the 35mm optical release prints designed for decoding with a Dolby matrix circuit (aka: Pro Logic).

For the Pro Logic to TRULY work properly though, the output of your print playback must be not only balanced level-wise, but frequency response-wise. To do this I would play a CD with pink noise through an EQ and record onto the track of the print to be re-recorded. Usually a minute or two (or make a loop out of the leader). Then I would rewind and play it back and look at the signal on a real time analyzer to see how flat it was. If I saw a dip at some frequencies, I would boost those frequencies on the EQ pre-recording and try it again. After a few passes you can fine-tune things so the final output is shockingly similar between the two channels of audio coming out of your projector. This means the Pro-Logic circuit in your receiver will do a far more impressive and discrete job.

Finally to top it all off, I encoded my prints with dbx Type II nose reduction. This gives dangerously close results to CD quality from Super 8 mag tracks, and no that is not an exaggeration. Used encoder/decoder boxes are all over ebay for under $50, but you need to do the equalizer/RTA step above before considering dbx encoding.

During the re-recording, project the 8mm image on the wall beside your tv at approximately the same size. Leave a foot or so of space in between the two images. Then watch that empty wall during the re-recording, NOT either of the images! All you are doing is watching for the camera cuts to flash exactly in sync with each other out of your peripheral vision. If you see one start to flash even a half frame before the other, by looking at the wall between the two images you will know exactly when to tap the speed control on the projector just a nudge to force them back into sync. By recording with this setup, you will never be more than 1 frame out of sync on the entire movie.

And of course, bonus points to those who change the potentiometer out on their projector that regulates speed control so they can turn the knob MORE to achieve LESS of a speed difference. That permits you to really make super fine adjustments to the speed during recording, even if one entire knob's rotation only ends up being 22.5 frames per second to 25.5 frames per second.

Posted by Evan Samaras (Member # 5070) on November 17, 2017, 04:06 PM:

I didn’t start this topic, but can’t thank you enough Brad for that detailed response. I wondered the same about utilizing Laser Discs for the sound. I have found that it is easier to rip the audio from DVD’s than Laser Discs.

Posted by Osi Osgood (Member # 424) on November 18, 2017, 10:46 AM:

WOW! good to hear form ya, Brad!

I agree, DVD is the way to go, unless what youre recording is a carttoon short or a short one reels super 8 of some kind. that would be annoying dealing with changes in reels in comparison to the running time for a side of a laserdisc.

... and, for a moment, i was thinking that i had a good new use for all of these ole laserdiscs lying about. [Smile]

Posted by Bill Brandenstein (Member # 892) on November 18, 2017, 12:00 PM:

Always great to benefit from Brad's extensive knowledge, so let me add my thanks as well.

I want to add a few technical details from my own workflow, which for those who are technically adventurous gives the best results. My home and work computers are Windows desktops and therefore both have multiple audio outs available right from the motherboard sound connectors. I also have used Adobe Audition personally and professionally for years, and if you happen to have Audition 3.0 you can do everything you'd ever want to do for Super 8 sound sync.

So with audio software that will play 2 wave files to 2 separate outputs on your computer's audio hardware, you can drive a wave file with a pulse to your projector from one output, and the soundtrack of your movie with the other. At 48KHz, that's 2002 samples between each pulse at 23.976 fps.

When I've replaced bad or mono Super 8 tracks, I've added a third track: I record the existing film sound in as a guide. Locked to the 23.976 pulse, this guide track makes a perfect re-do much easier for obvious reasons. If you happen to video the image during transfer (with sound up, please!!!), you can also scrutize any sync errors in the original transfer, but I find that usually this is done very well on Super 8 prints and no corrections are necessary.

The trick and advantage of this now comes into play. If you transfer your replacement audio into your computer digitally, you merely trim or edit your replacement sound source to match your film audio. Simple enough, right? Well, no. There are too many sources.

Analog sources like VHS or old Laserdiscs have to also be digitized to match the 23.976 frame rate. I happen to have access to old Tascam 8-channel DTRS machines, which are now available inexpensively on eBay. Why this is important is because a DA-88 with the SY88 card, or later DA-78s or 98s (make sure it has analog in/out!), have the ability to accept an incoming NTSC video signal (standard def) as a clock source. Well, there you go. You can hook your VHS or Laserdisc video up and digitize the analog audio at precisely the correct sampling rate. So set it up at 48KHz and go! You don't even record to a tape if you're using a DA-78 or DA-98, you simply route the audio pair to a SPDIF output and capture the SPDIF with your computer sound card. OK, so there's another workflow requirement: you need SPDIF in and out. But once that transfer is done, you can edit the audio to minimize the hum and buzz from VHS Hi-Fi tracks, or even reduce noise on analog video tracks.

Later Laserdiscs have uncompressed PCM stereo tracks identical in quality to Compact Disc, which is lovely. Obviously you can also record a 44.1KHz digital track from a laserdisc if your player has a SPDIF output, which for most Hollywood movies sound great in Pro Logic as Brad mentioned. In that case your Sync work has to either be set up for 44.1 KHz, or you need to do a conversion to 48Khz (recommended).

You can also rip a DVD, and I understand Blu-ray can be as well, and convert the audio tracks to Wave files. Your mileage will vary depending on which audio tracks you rip, how many channels are present, and whether your software reads a Dolby Digital 5.1 track as 6 channels or as bass-less, dynamically limited stereo downmix. You can also rip ac3 or DTS data directly (I've never tried the latter) and work it up as a SPDIF-wave for 5.1 playback from your computer.

Let's talk about "SPDIF-Waves" a moment. When your DVD player sends a 5.1 stream to a receiver, it's dropping compressed data through a 48Khz, 2-channel, 16-bit container. If you capture or create that information as a 48K/x2/16bit file undecoded, you have a SPDIF wave. The trick is that in no instance may a single bit of that information be altered or dithered. The slightest corruption ruins the 5.1 playback.

One of the other advantages of Audition 3.0 is you can drop into your playback track a Dolby Digital SPDIF stream as converted to such a 48Khz, 16-bit stereo wave file (this consists of a series of very loud bursts of noise if played back as PCM). Audition 3.x, and this one only, does NOT touch the data if your gains are unity and all other processing is off (panning, EQ, etc). Pretty much all other audio DAWs add dither, so they won't work. Hook a SPDIF connection from your computer output of that track to any basic home theater receiver, and your SPDIF-Wave will be heard by your receiver as if it's playing from a DVD. There, you now have the ability to do 5.1 with Super 8, locked with no drift. Unfortunately "Fantasia 2000" is the only feature I have with this capability, but some other shorts or trailers sound great this way too.

As a result, I have a small library of Super 8 sync folders on my computer with the ability to add digital stereo or surround to my presentations. Some were silent prints to begin with, so just added mono sound, some had bad transfers now made good, one has a faulty sound stripe, and most had stereo or 5.1 tracks existing in the video world but the Super 8 track was mono.

Anyone still with me? Was that helpful at all?

Posted by Stuart Reid (Member # 1460) on November 18, 2017, 03:11 PM:

This is a fabulous thread, thanks all for sharing some impressive methods of syncing super 8. Now, here's a question, is there any way of recording the digital bitstream onto stripe, then using a home cinema amp to decode?

Posted by Bill Brandenstein (Member # 892) on November 18, 2017, 05:59 PM:

I don't think so, Stuart, as the data bandwidth needed far exceeds the bandwidth capabilities of one (or two) tracks at 10/cm per second.

A question for Brad: ever gone into the internal projector workings to calibrate record bias and levels, and playback levels, to help achieve good Pro Logic results with a stereo track?

Posted by Winbert Hutahaean (Member # 58) on November 18, 2017, 06:40 PM:

This thread is really magnificent especially after Brad's input.

Unfortunately the title does not show the importance message inside. So if Osi can edit the title.please to something like "DIY how to record stereo sound from LD/DVD to super 8 tracks".

And to Doug, could you put this into technical compilatuon thread please.

Cheers,

Posted by Stuart Reid (Member # 1460) on November 19, 2017, 02:23 AM:

In which case Bill even if the bandwidth is too low for that, I wonder if there's enough to hold the DTS timecode? Imagine a GS1200 syncd with a DTS player!

Posted by Winbert Hutahaean (Member # 58) on November 19, 2017, 05:04 AM:

quote:
I wonder if there's enough to hold the DTS timecode?

There is another method that MIGHT work.

In DJ community nowadays, vinyl is no longer used but the turntables (record player) are still used. Why? Because the DJ are using timecode vinyls while the sound coming out from digital format (MP3).

What is timecode vinyl, i.e a vinyl with normal groove like the ordinary vinyl but bringing only signal (like fax machine sound).

This signal become code for the MP3 when to start, speeding up/down or stop.

I don't know if this timecode sound is recorded to super 8mm tracks will also work the same. Obviously the film soundtrack is now stored in MP3.

So no matter the projector plays speed up/down or stop, the MP3 will follow.

Any comment?

Posted by David Hardy (Member # 4628) on November 19, 2017, 05:11 AM:

If the question were quite simply " what has the better audio quality Laserdiscs or DVDs and Blu-Rays ? " My reply would have to be Laserdiscs.

I don't like the compressed digital sound from DVDs/Blu-Ray discs.
Even the good old simple 2 channel audio on laserdisc sounds better. Be it Mono or Stereo.

Posted by Stuart Reid (Member # 1460) on November 19, 2017, 03:33 PM:

Winbert I could see that working but you'd have to know the projector was absolutely locked at 24fps in order to make sure it is sync-locked to the timecode. Of course once the timecode track is recorded it can then be played back on any machine that has a slight speed inaccuracy as bybthat point it will be the master to the audio speed slave, yes? And imagine if we can record only on the balance stripe, leaving the main stripe as a fallback. Love the idea!

Posted by Bill Brandenstein (Member # 892) on November 19, 2017, 05:32 PM:

Stuart, there's no reason a DTS timecode couldn't go on the balance stripe. If there's any problem with that at all, it would be that the bandwidth would be too LOW!

David, I agree that the uncompressed digital tracks on Laserdiscs were special. Pristine sound with that perfect PCM clarity! However, discrete 5.1 is worth the lossy compression in my opinion because it's so much more immersive when mixed well. That's a big IF, though. However, Blu-rays with DTS Master HD or other such formats are essentially lossless compression in 5.1, so you can't beat that.

Posted by David Hardy (Member # 4628) on November 20, 2017, 06:43 AM:

Bill I agree with you about DTS sound.

When I was cinema a projectionist we used to have Digital Sound , DTS Sound and Sony S.D.D.S sound options with some prints.

One time using the same film I compared the sound options.
I was in the auditorium while another projectionist switched between the various sound sources randomly.
So this was in a way not unlike a Hi-Fi sound blind test.

I kept a score chart and the times for my preferences at various points.
The other projectionist kept note of the times and what sound source could be heard and other variables such as volume.

I found I preferred the DTS sound more than the others.
I found it to be more rich and smooth and more natural sounding.

Of course this is only my subjective preference and others may not agree.

Posted by Bill Brandenstein (Member # 892) on November 20, 2017, 04:01 PM:

Some years ago our local Audio Engineering Society held a meeting at a movie theater and went switching back-and-forth between the various formats. DTS won there also.

And I think Dolby AC-3 sounds great so far as lossy compression goes.

Just want to encourage any of you who are collecting Blu-ray to note that many of the newly remastered titles have "Dolby" or "DTS" tracks that are NOT lossy compression as we're accustomed to on DVD, but are fully lossless. Read the fine print!

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