Film-Tech Forum ARCHIVE: Buzz out of Center Channel

This is topic Buzz out of Center Channel in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Tracy Bellar (Member # 3049) on 12-01-2010, 07:30 AM:

I will have to get the make of all the equipment later to fully get this issue resolved I'm sure. But here is the basics. We are having a buzz (white noise) from our center channel. This is not a digital house. It is a red sound head. I will get the necessary make of equipment today. I will list all amps processor and EQ.
We have changed out the processor and it did not help. We have changed out the sound head with no results. We have isolated each amp trying to pinpoint the cause.
We have been able to eliminate the buzz slightly if we only connect it up to run in mono. But this is not a fix.
When the buzz is coming out of center and you unplug the center channel the buzz moves to left and right channel. Which is a different amp.

Currently the automation is not working in this house. Manual startup. It is a homemade console made by Dan Worthington. A few relays are not working.

Also this projector was recently rebuilt. I just want to provide any info possible. If all this info helps I hope to get a answer from someone who may have experienced this and has a quick fix. If not I will list all the components in a few hours.

Posted by Sam D. Chavez (Member # 1841) on 12-01-2010, 09:46 AM:

What exactly are you unplugging when you say you unplug the center channel? The power cord, the input audio cable, etc.?

Posted by Tracy Bellar (Member # 3049) on 12-01-2010, 01:40 PM:

The audio input.

Posted by Monte L Fullmer (Member # 2797) on 12-01-2010, 04:02 PM:

? ground loop issue ?

Posted by Tracy Bellar (Member # 3049) on 12-01-2010, 04:54 PM:

This is just an idea. Also a question. Since the automation is out due to burned out relays could this be coming through the crossover? Actually from a defective relay say mixing in some white noise from the music channel along with the movie sound?
We have been concentrating on Amps, Processor, and sound head.

It just seemed strange that when the center channel wasn't connected that it didn't eliminate the buzz it only moved to another channel. Left and Right.