8mm Forum: Sound problem with Bauer P7 projector

This is topic Sound problem with Bauer P7 projector in forum 16mm Forum at 8mm Forum.

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Posted by Dave Cragg (Member # 401) on November 14, 2011, 04:13 PM:

Hi All,
I'm new to 16mm and am a complete novice when it comes to the technical side of our hobby, so I'm hoping someone can help me here;
The sound from my optical sound films sounds warbled/muffled through both the internal and external speakers. I've tried all 4 of my films (several times)and it's the same. Below is a photo of the sound drum and exciter lamp.

Hopefully it is something straightforward that I can fix.

I'd be very grateful for any suggestions, especially as I am having a few friends around on Saturday for my first 16mm film show (and some homebrew lager and porter!)

Thanks a lot,
Dave

Posted by Nick Field (Member # 2132) on November 15, 2011, 02:03 AM:

Hi dave, just check the film path through the lower half of the projector/after the gate when running. Check make sure the lower loop is sufficiant as if this is too tight this can often cause the film to vibrate in the sound drum, also lamp alignment may need to be checked, also check if the pinch roller is tight enough or operating correctly, usually it's something simple as there ain't much to go wrong really. [Smile]

Posted by Dave Cragg (Member # 401) on November 15, 2011, 03:46 PM:

Hi Nick,
your reply is much appreciated.
I've 'fiddled about' and the sound seems ok now without me being sure what i've done (mainly manually increasing the film loop before it reaches the sound head). It's worrying as I don't feel confident that I've actually done much, and frustrating as I'm sure it would take someone of your experience about 2 minutes to definitely sort the problem.

I'll keep you posted as to how I get on.

Thanks again,
Dave

Posted by Dave Cragg (Member # 401) on November 18, 2011, 03:44 PM:

Hi Nick,
have cleaned the film path as best I can, and have made every adjustment I can see yet I can't fix the problem. At times I can get great sound out of each of my films, but not consistently.

Does anyone know someone in the Merseyside area who can service and maintain a 16mm projector?

This is my first experience with 16mm and after looking forward to being able to buy a projector I have to say I'm pretty downhearted. Worst of all. I'nm sure it's a quick job for someone who knows what they are doing!!!

Thanks again,
Dave [Frown]

Posted by Nick Field (Member # 2132) on November 18, 2011, 03:55 PM:

Hi Dave,sorry that you are still getting trouble, if I lived a lot closer to Merseyside I would have a look at it for you but we are a fare few miles apart unfortunatly. [Roll Eyes]

Still I hope you manage to find somebody in your area.
It sounds like as if the light image shining through the soundtrack is running too close to the outter edge of the film.

Posted by Tommy Woods (Member # 2437) on November 18, 2011, 05:36 PM:

Hi Dave,I had a similar problem with one of my projectors,and after a frustrating 3 days found that someone had fitted the wrong exciter lamp,I have noticed that yours is the vertical element type,they also come with a horizontal element,I would check you have the right one fitted,this may be of some help or not!!You should look in your manual if you have one,or maybe some sage on here would know?

Posted by Claus Harding (Member # 702) on November 18, 2011, 07:03 PM:

Dave,
Tommy's idea is a good one; I bought a machine where the seller told me the sound was "bad" and it was just the exciter bulb that was wrong.

Have you tried adjusting the optical lens which is situated right next to the drum?
I don't use those particular projectors, but if you loosen the set-screw for the little lens, you will find you can adjust the lens (in your case, sideways) and if it is set wrong, it will make a big difference in your sound. It will go from muffled to terrific to muffled again as you pass "the sweet spot."
You can, with care, run a film, loosen the set screw just enough, and then move the lens to see how the sound changes. When you find the optimal spot, tighten the set screw again.

I can't guarantee that is the problem, but it could be.

Claus.

Posted by Robert Lewis (Member # 1458) on November 19, 2011, 12:19 PM:

From what I have read about your problem, I am not sure that the cause is tightness of the film on the sound drum, but rather slackness. If the film is not tight on the drum you will get heavily distorted sound. On the Bauer P7 and 8 projectors, as on others, there is a pair of rollers which "float" so ensuring that the film is held at the correct tightness around the sound drum. These rollers are "managed" by a small spring which is positioned behind the rollers. If this spring has broken, become displaced, or has lost tension, it allows the rollers to open and the film to become slack round the sound drum. May I suggest you have a look at the spring and see if all is well? I do not think the fact that the filament in the exciter lamp is vertical is related. Certainly on my P7 projectors (which I think are almost identical to the P8 in respect of the sound head arrangement) the filament is vertical and causes no problem.

Posted by Adrian Winchester (Member # 248) on November 19, 2011, 02:44 PM:

A P8 I obtained a few months ago had sub-standard optical sound and as the magnetic sound was fine, I guessed the problem was the optical lens, as mentioned by Claus. Fortunately, I was right and I managed to fix it. However, I'd be wary of moving the lens unless you rule out the other possibilities, because to get perfect sound, the lens needs to be adjusted with immense precision. I eventually managed to come up with a technique that works for me, but it's a challenge for someone without specialist skills and equipment, so it would be a frustrating thing to play around with and then find it hasn't solved the problem.

Posted by Don Sykes (Member # 1059) on November 21, 2011, 08:47 AM:

Hi Dave, Where abouts in Merseyside are you? I live in Ainsdale, Southport. Merseyside and may be able to help. Give me a call on 01704 578348. Should be a simple fault to sort out. Regards Don.

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