8mm Forum: Wobbly Music Track

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Posted by Daniel Macarone (Member # 5102) on March 13, 2016, 08:14 PM:

Have you ever heard a soundtrack on a print that had a score that was wobbly in pitch? I've heard a few of these. The dialogue and sound effects sound fine, but perhaps I can't notice they are wobbling, too. Does anyone know what causes that? I believe there is only one sound wave for everything on a Super 8 soundtrack and not a separate one for music.

Posted by Clinton Hunt (Member # 2072) on March 13, 2016, 09:11 PM:

I think it is dirty sound head or maybe it's not running at a constant fps?
I am sure the answer will appear quickly here being a great forum! [Smile]

Posted by Terry Sills (Member # 3309) on March 14, 2016, 03:22 AM:

I had exactly this problem and upon investigation found that the main drive belt was faulty. When I changed the belt it was fine. I suspect you have the same fault. It's certainly the first thing you should try.

Posted by Tom Photiou (Member # 130) on March 14, 2016, 02:41 PM:

Either that, or the film either needs a clean,(for lubrication), or it may have a little too much on already as some of my prints did.
Changing the belts and ensuring the projector has been lubricated in the correct places if hasn't been done for years is also very important. [Wink]

Posted by Rob Young. (Member # 131) on March 14, 2016, 03:02 PM:

Daniel, this is either referred to as "wow" (when the soundtrack, or most noticeably music, changes pitch, ie. is slowing down and speeding up gently) or "flutter", (where there is a chatter within the soundtrack, again, often most noticeably with music.

This isn't refined to film, but a common issue with any analogue system such as tape recorders, etc.

Super 8 is prone to such issues, most commonly "wow".

Even the very best super 8 projectors can be at fault.

There are numerous causes.

Even though the soundtrack is provided on a single magnetic or optical track, "wow" is more often only apparent with music reproduction, the ear somehow more forgiving with speech or sound effects.

However, this still remains a mechanical fault and let me tell you there are a multitude of reasons when considering super 8 (and larger formats for that matter), even down to the print itself.

"Flutter" is often due to a fairy obvious mechanical issue with the projector, sometimes even just down to bad design.

Maybe you could give us a few more details, such as the projector you are using, the print, etc.

Maybe even a recording or video?

Best,

Rob.

Posted by Andrew Woodcock (Member # 3260) on March 14, 2016, 03:11 PM:

I can honestly say Rob, aside from duff recordings on some soundtracks to begin with, there are one or two models I've used that never ever pose a problem with wow or flutter to my ears, at least.

Perhaps not the most sensitive in the world, but not without an acute awareness for such matters either.

I think it's certainly true some projectors are more susceptible to these issues than others anyhow.

I have even got away with excessive amounts of filmguard coating the places it ought not to on two of the projectors I have used without ever causing an issue apart from a glistening capstan roller.

There is a section or two on The Secret Of N.I.M.H. and Lethal Weapon that is like fingers down a chalk board in the heavily Laden string section of the orchestral backing track, but no matter what machine I've ever played these two films on, it still always sounds identical.

One I can and will be doing something about, the other sadly, I cannot.

I am surprised to hear Rob, that you find all machines can give issues regarding these matters.

Posted by Rob Young. (Member # 131) on March 14, 2016, 03:26 PM:

Andrew, I moved to a Beaulieu 708el because my beautiful Elmo ST1200HD, even with it's floor shaking stereo sound was prone to random "wow" even with new Derann, poly, stereo prints, despite every adjustment or print treatment under the sun.

Some reels, even from the same feature would be fine, others not.

It drove me crazy, and with lots of money spent an various mods and tweeks.

Even gentle "wow" makes me cringe.

I've had in my possession 3 or 4 Elmo GS1200's over the years and all provided random "wow".

I've witnessed Xenon GS1200's at film conventions over the years give the most ear aching "wow". I'm not criticising anyone, just pointing out that nothing is perfect.

Except, maybe the 708el.

[Smile]

Posted by Andrew Woodcock (Member # 3260) on March 14, 2016, 03:35 PM:

It's quoted rating is perfect Rob, or almost ha ha, but I'm not saying for one minute aging machines can replicate these measured design specs.

But even besides the 708, I can honestly say I have witnessed a few others where if it's present, it's certainly very very negligible and doesn't spoil any soundtrack that is good to begin with.

I've heard GS 1200's and on the films I've seen with them, they weren't too bad either, not at least once they had settled down into the film anyhow.
I cannot say the same for any of the ST 1200's I've owned though if I'm honest, especially at the beginning of a film or immediately after a splice.

Posted by Daniel Macarone (Member # 5102) on March 14, 2016, 03:51 PM:

Rob, thank you for the knowledgeable answer. My machine is the Elmo ST-1200HD and the belts have a little over 100 hours of use. The "wow" only happens on certain prints. I had a print of Gunga Din that did it for the entire score. I just bought The Third Man and there is only one scene where the music has the wow. And I have RBC prints of Modern Times and The Circus and I hear the wow for only a scene or two. I don't mind when it's that seldom. It's interesting to hear it's the equipment that might cause it. I think I know what the "chatter" is and that happens on certain prints always the same way.

Posted by Andrew Woodcock (Member # 3260) on March 14, 2016, 03:56 PM:

Daniel, have you had the opportunity to view these prints on any other machine to see if there are any differences during the problematic scenes?

There is a chance it may be the original track, but you would only know one way or another by trying them on another machine.

Posted by Paul Adsett (Member # 25) on March 14, 2016, 08:25 PM:

Daniel, IMO Elmo projectors are susceptible to WOW by nature of the design of the capstan and roller. The brass capstan is too small in diameter, as is the rubber pressure roller. The WOW is the result of slippage of the film at the capstain and sound head, as a result of the varying tension on the take up reel. You can prove this by relieving the tension of the take up (by holding the take up reel from turning), and then all WOW will disappear. Not all films have WOW on Elmo projectors, in fact most do not, but the projector design results in WOW if the film is a)too slippery or b) the film take up torque is not absolutely smooth, or c) the clamping force on the sound capstan roller is slightly weak.
Eumig projectors do not have any of these problems, no matter the condition of the film. This is because all Eumig's have large diameter stainless steel capstan rollers and large diameter rubber pressure rollers, and large clamping roller force. I have never heard any WOW on any Eumig projectors with any film.

Posted by Andrew Woodcock (Member # 3260) on March 14, 2016, 08:27 PM:

Mr pro engineer, once again here. I doff my cap!

Paul outlines and details here, what I was speaking of earlier to Rob.

I too, include the Eumig models I've used in this excellent appraisal/ assessment here by Paul, especially the "High Quality Sound" models, of any variant.

Eumig placed great emphasis on sound in particular with regard to their later Super 8mm models. All feature a very large stabilizing Capstan Roller.

A lot of good Super 8mm projectors fare very well in this department, just not some of the most obvious choices you may select, as it transpires.

[ March 15, 2016, 05:42 AM: Message edited by: Andrew Woodcock ]

Posted by Daniel Macarone (Member # 5102) on March 14, 2016, 10:40 PM:

Paul, thank you. That's really great knowledge. I'm always happy to learn more.

Posted by Andrew Woodcock (Member # 3260) on March 15, 2016, 05:31 AM:

Daniel, have you had the opportunity to view these prints on any other machine to see if there are any differences during the problematic scenes?

There is a chance it may be the original track, but you would only know one way or another by trying them on another machine.

Posted by Rob Young. (Member # 131) on March 15, 2016, 08:12 AM:

Paul's analysis of the ST1200 design is spot on of course.

That said, it's still a beautifully made, rock solid machine which can sound superb when behaving itself.

Elmo did introduce a mod for later machines, which was a rubber coating on the brass capstan. It didn't really help!

Andrew is right to try them on another machine of course.

One thing to look for during a "wowy" section, is (with the front cover open) watch the two small, sprung jockey rollers near the bottom of the film path, below the sound capstan and pressure roller.

If these are "dancing" or moving up and down, it is a mechanical cause, with the film tension not being steady.

As Tom has pointed out, this can actually be due to the film not being sufficiently lubricated, but can also ironically be due to over lubrication!

Posted by Andrew Woodcock (Member # 3260) on March 15, 2016, 08:46 AM:

These are very susceptible machines to film lube Rob, it does have to be said.

Posted by Brad Kimball (Member # 5) on March 07, 2017, 10:12 AM:

I have 3 Chinon projectors (6100, 7000, 700MV) and whenever there's music I get flutter on all 3. It drives me insane. All three units have varying degrees and hours of use. When there's dialogue - no flutter. Now with projector bulbs all slowly going on permanent moratorium (DNE being the most recent) I just plan to make the best of it until I'm forced to bin my projectors because I can no longer acquire the lamps for them [Frown]

Posted by Andrew Woodcock (Member # 3260) on March 07, 2017, 10:14 AM:

Simple solution to your problem Brad. Buy a different make of machine, ones which lamp replacement poses no imminent threat of extinction and ones which wow and flutter will also never cause you a concern.

A nice Eumig 938/40 may fit your requirements well.

Posted by Brad Kimball (Member # 5) on March 08, 2017, 03:20 PM:

Thank you, Andrew. The only thing is that the models you mentioned are really designed for someone who does alot of mixing/re-recording whereas I just watch. I just wouldn't want to pay for extras that I would never utilize. I agree, a different brand may be in order.

Posted by Andrew Woodcock (Member # 3260) on March 08, 2017, 03:38 PM:

An S938 makes the perfect "viewing" projector Brad.

If it can mix, record well, play in Stereo etc etc etc,

Chances are, it can project films better than most!
That's the difference!

Don't believe for one minute, that if you want to watch a film without Wow, flutter, scratches and unsteady image, without noise and duress, you don't need one that will record on films in a similar manner.

The two run hand in hand.

They are designed with all these factors in mind and the less you actually needed, the less you actually got, in every aspect!!

Posted by Brad Kimball (Member # 5) on March 08, 2017, 04:42 PM:

Great info. Thank you so much. I'll definitely keep this in mind.

Posted by Andrew Woodcock (Member # 3260) on March 08, 2017, 04:43 PM:

Please do, it will serve you dividends in the future!

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