Film-Tech Forum ARCHIVE: intermission music problem

This is topic intermission music problem in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=008202

Posted by Gary Meyer (Member # 2936) on 08-15-2006, 09:37 PM:

We installed a second projector so we can show archival prints and do changeovers. The result is that our intermission music doesn;t shut off automatically when the projector starts...it used to. So it is playing simultaneously with the fil's sound until we do a manual switch off.

Any ideas?

Posted by Jack Ondracek (Member # 1466) on 08-15-2006, 10:12 PM:

What are you using for a sound processor?

Posted by Monte L Fullmer (Member # 2797) on 08-16-2006, 05:12 AM:

If a selinoid dowser is used, one could place a microswitch to where when the dowser opens, the microswitch is opened also which would cut the N/S off heading to the amplifier...if one is mechanically able to construct such a device ...

..but true..what kind of processor (if any) is used, or just a switch box that switches the sound between machines when doing the changeovers..

Looks like an "A/B" switch (DPDT switch) needs to go into the circuit.

-Monte

Posted by Ken McFall (Member # 845) on 08-16-2006, 04:38 PM:

In a normal automated system the projectors 'DO NOT' control sound format selection. They only control projector selection 'ONCE'the sound format has been changed to film.

On the projectors there would be one with a switch that would determin which projector was 'active'. On Dolby systems this would be a SPDT, change over, switch, that would be operated by the shutter control system.

That being the usual case I would suspect that when the second prjector was installed the original format selection wiring was disturbed in some way. The sound format selection would not need to have been changed in any way with the addition of a second projector. The only wiring change would have been the addition of projector selection wiring to the processor.

I would suggest you take a look at the way the wiring was changed with the new projector installation as the fault is most likly there.

Just to make it clear....

The automation would normally make the format selection, ie film or non sync.

The projector(s) would make the selection as to which projector was 'active' (Shutter open on number 1 then number one 'active. Shutter closed on number one then number two 'active')

Hope this helps.

Regards Ken.