[MacDV] Radio microphone noise

[Karl Hayden]

In the room where you are recording sound are there any fluorescent 
lights?  I know you checked your power supply and discovered that was 
the main cause. But sometimes fluorescent lights can cause a hum, his 
or buzz on a recording.



On 13 Jul 2004, at 21:48, Derek Roff wrote:

> I'm shooting video indoors in a classroom, using an Sony trv950 
> camcorder. I've had lots of problems with microphone noise.  Hums and 
> buzzes have plagued all my wired microphones.  The wireless mic, Sony 
> WCS 999, has given good, clear sound 90% of the time, with aggravating 
> intermittent "sssnickk" sounds.
>
> Today I discovered that the Sony power supply/charger is the source of 
> the hum on the wired microphones.  The obvious solution is to unplug 
> the camera and run off the battery.  The problem is that I am shooting 
> five hours in a row, each day.  I don't have that much battery 
> capacity between charge cycles, if I use the lcd view screen.  If I 
> use the viewfinder, the batteries may last, but my brain will be 
> destroyed by five hours of squinting through the vewfinder.
>
> In any case, the wireless mic is a better choice for capturing the 
> voices of the roaming teachers.  The sound that I get, at random 
> intervals from three to thirty seconds apart, is kind of a hiss, 
> ramping up in volume quickly to a sharp cut off.  It sounds like 
> electronic interference of some sort.  The sound reminds me of sound 
> effects in science fiction movies. Perhaps the spark traveling up the 
> wires in Frankenstein's lab.  Roughly 1/2 second in duration.
>
> We are in a small building on the campus of a small college in 
> Vermont, a mile outside a small town.  I think I am fairly isolated 
> from large scale electrical disturbances, radio stations, airport 
> control towers, and the like.  No telling how the building is wired.  
> The lights are incandescent. There are dimmers on the light switches, 
> but testing them while listening to the microphone through the camera 
> hasn't shown any obvious difference between off, on and in between.
>
> Any suggestions and speculation will be welcome.  I am also wondering 
> about Sound Soap or other software to decrease the severity of the 
> problem in post production.
>
> Thanks for you thoughts,
>
> Derek
>
> Derek Roff
> Language Learning Center
> Ortega Hall 129, MSC03-2100
> University of New Mexico
> Albuquerque, NM 87131-0001
> 505/277-7368, fax 505/277-3885
> Internet: derek at unm.edu
>
>
> ----------
> <http://www.themacintoshguy.com/lists/MacDV.html>.
> Send a message to <MacDV-DIGEST at themacintoshguy.com> to switch to the 
> digest version.
>
> XRouter | Share your DSL or cable modem between multiple computers! 
> Dr. Bott | Now $139.99      <http://www.drbott.com/prod/xrouter.html>
>
>   Cyberian   | Support this list when you buy at Outpost.com!
>   Outpost    |         http://www.themacintoshguy.com/outpost.shtml
>
> MacResQ Specials: LaCie SCSI CDR From $99! PowerBook 3400/200 Only 
> $879! Norton AntiVirus 6 Only $19! We Stock PARTS! 
> <http://www.macresq.com>
>
>