8mm Forum: Sound problem with a Bell and Howell Specialist

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Posted by Bradford A Moore (Member # 426) on January 29, 2010, 07:16 PM:

I recently got a Bell and Howell Specialist. The overall running of the projector is great but I'm having problems with the sound. I took it to guy who works on audio equipment, and very knowledgeable. He realigned the sound drum with bulb. and relubercated the rollers. Some films sound ok, but not perfect, and others sound horrible. I don't think it is normal either to turn the volume all the way up to hear it.

My guess is it might be be the amp, but what aspect. Any info would be great. I would like to take it back with any suggestions. Other than the sound it is a smooth running machine.

Posted by John Hermes (Member # 1367) on January 29, 2010, 07:25 PM:

He might have not focused the sound lens correctly. It takes very fine adjustment, best done with SMPTE test film and the right tools. Everything has to be aligned correctly as far as the rollers and guides too. I have done this before and it takes patience and care. There are two SMPTE test films to align everything, sound focusing and buzz track. If the amp were bad, it would probably be bad all the time.

Posted by Simon McConway (Member # 219) on January 30, 2010, 06:16 AM:

I'm afraid this guy who worked on the machine could have made things worse. I've heard various horror stories from people who've said "I took the projector to a guy who's an engineer"...they could be a first-class engineer, but that wouldn't gave them the first clue about working on projectors. I'm confused where he said he'd re-aligned the sound drum...this isn't really able to be aligned. The exciter lamp slit can be aligned, but the sound drum itself is fixed. I think your best bet may be to try a whole new soundhead. Gordon Ogbourne, here in the UK, should have them. Don't trust your machines to anyone unless they've had experience (and plenty of it) on projectors.

Posted by Bradford A Moore (Member # 426) on January 30, 2010, 08:08 AM:

Sorry for the confusion. He didn't touch the sound head, but aligned the lamp with the lens, which was out of place. I think at one point before I got the projector it had been banged, because there is a dent in the speaker screen. Some of what I play through it sounds ok, but some of the high end sounds a bit garbeled. I also think it should be louder than it is.

Posted by John Whittle (Member # 22) on January 30, 2010, 08:34 AM:

Garbled sound can result from a loose loop around the sound drum. When the film is threaded and the projector stopped, you should be able to move one of the dampening rollers and have the other follow and be tight against the film around the sound drum. If it isn't, the film wasn't threaded right or something is loose.

This would also result in very low sound output. The focus of this is very critical which is why you need the SMPTE 7,000 hz focus film to set the sound optics along with an meter to watch the output as you move the lens. It doesn't take much to go from high to zero and you have to go in the right direction to have a split focus for A and B wind prints.

John

Posted by Bradford A Moore (Member # 426) on January 30, 2010, 08:41 AM:

The Focus is sharp as can be. I will check on the rollers. How would you move one of the dampening rollers?

Posted by Chip Gelmini (Member # 44) on January 30, 2010, 03:10 PM:

Hi Brad

Try this before you do anything with the rollers, because they could infact be fine.

1. While a film is running

2. Push up on the black retaining plastic that holds the film in place on the BOTTOM of the BOTTOM SPROCKET. This is that trap door thing that when you push it down you remove the film for manual un threading.

3. I have a B&H 2592 that has a garbled sound. When I press up on this plastic retaining cover, the garble goes away.

4. I have yet to figure out how to repair it. However,

5. There are two screws revealed when pushing this plastic down. There is one on each side of the bottom sprocket.

6. Check to see that the left screw is tight.

7. Check to see that the right screw is just alittle loose (you can have "snug" you can have "tight" --> so make it "almost snug")

8. If I am right, setting the right screw "almost snug" will reduce the garbaled sound but it will not eliminate the problem. Also, as set "almost snug" there is no danger of it vibrating loose and falling out.

9. Also try and see if this garbaled sound problem happens when the take up reel is pulling on the film during normal play. Stop the take up reel with your hand and let slack film pay out and see if during that time if the sound problem dissappears and then let the take up reel work again and see if the problem is back, etc.

10. It might be worth the effort of trying to get another projector that would not have this problem to fall back on.

Now there is a big difference between your specialist and my 2592 but this area of detail should be almost identical.

As for the volume problem, how clean is that slit lens. Also, what kind of optical track are you running, because the really early first generation sound 16mm prints where varaiable density which is a different kind of optical track. It is my guess the films that sound better in your machine have the standard optical track, the two separate squiggly lines.

Hope that helps and please let us know as I am curious.

Chip G in Falmouth

Posted by Bradford A Moore (Member # 426) on January 30, 2010, 04:51 PM:

Hey Chip,

What do you clean the slit lens with? I would think i would get better volume, without having to put it all the way up. I did clean the everything that I could, and the sound was better. I'm curious about the lens, and there is annoying squeak that i can't detect where its coming from either.

Posted by John Whittle (Member # 22) on January 31, 2010, 01:23 PM:

Is this an autoload machine perhaps?

To clean the sound optics, you need to remove the cover for the exciter lamp, remove the excter lamp and using a Q-tip with lens cleaner, clean both the side towards the exciter lamp and the other side which focuses the slit on the film. There is no user adjustment for the focus of the slit since it needs to be done with equipment.
John

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