Boom Acting like an antenna? at DVinfo.net
DV Info Net

Go Back   DV Info Net > The Tools of DV and HD Production > All Things Audio

All Things Audio
Everything Audio, from acquisition to postproduction.

Reply
 
Thread Tools Search this Thread
Old February 22nd, 2004, 10:41 PM   #1
Regular Crew
 
Join Date: Feb 2004
Location: Toronto, Canada
Posts: 76
Boom Acting like an antenna?

I did a bunch of sound tests with my new shockmount and boom. Shockmount works great. Needs some tweaking, but it should be fine.

The thing is that I pick up radio or tv signals with it! My mic is connected to a pre-amp, and than to a 20GB jukebox. I get this weird static, and sometimes I hear people talking, and music. Its really quiet. I get it even when the mic is off. So im gussing the pole acts like an antenna, the coiled extension cable is fed into the amp, which amplifies this interference, and feeds it into the jukebox, which records it.

The cable itself is shielded, or at least thats what it says on the box.

Any ideas?
__________________
PlanetBoredom.net
Yegor Sak is offline   Reply With Quote
Old February 22nd, 2004, 10:57 PM   #2
Retired DV Info Net Almunus
 
Join Date: Dec 2001
Location: Chicago, IL
Posts: 6,943
Tell us more about the microphone and cabling you're using. In particular, is the cable connection of an XLR type?
__________________
Lady X Films: A lady with a boring wardrobe...and a global mission.

Hey, you don't have enough stuff!
Buy with confidence from our sponsors. Hand-picked as the best in the business...Really!

See some of my work one frame at a time: www.KenTanaka.com
Ken Tanaka is offline   Reply With Quote
Old February 22nd, 2004, 11:01 PM   #3
 
Join Date: Jan 2004
Location: Stockton, UT
Posts: 5,648
A loose or undone shield will do this, and quite regularly. In fact, you can coil up a crappy mic cord and actually talk into it for a microphone. We used to have a cable just for this effect back in the days of 2" tape machines.
Also, even with a good cable, if it's wrapped around a metal object, it can become an antenna.
Use ONLY XLR cable, and even then, you should be looking at a Quad Star type cable or similar. This should kill your problem.
__________________
Douglas Spotted Eagle/Spot
Author, producer, composer
Certified Sony Vegas Trainer
http://www.vasst.com
Douglas Spotted Eagle is offline   Reply With Quote
Old February 22nd, 2004, 11:03 PM   #4
Regular Crew
 
Join Date: Feb 2004
Location: Toronto, Canada
Posts: 76
Im a student, so I don't have heaps of cash.

I use AT55 Shotgun, and a radio shack bought pre-amp, as well as some shielded gold plated wires.

I was informed that the actual pre amp might not be shielded or its just very low quality. I get the static even when the mic is off.
__________________
PlanetBoredom.net
Yegor Sak is offline   Reply With Quote
Old February 22nd, 2004, 11:30 PM   #5
 
Join Date: Jan 2004
Location: Stockton, UT
Posts: 5,648
Then it's definitely either preamp or cable....If you bought the cable at Radio Shak, I'd also be looking at those as a big part of the problem.
You can usually find even used mic cables around, and resolder the ends if they are weak/broken. that's usually a better answer than cheap. One place you can never go cheap is cables. And going cheap with the Pre definitely carries some issues too...but if it's what you got, it's what you got..
__________________
Douglas Spotted Eagle/Spot
Author, producer, composer
Certified Sony Vegas Trainer
http://www.vasst.com
Douglas Spotted Eagle is offline   Reply With Quote
Old February 22nd, 2004, 11:40 PM   #6
Regular Crew
 
Join Date: Feb 2004
Location: Toronto, Canada
Posts: 76
Further tetsing revieled that the pre-amp was very low quality. I'll be returning it back.

I was thinking, why bother with recording audio to another device, if I can just get a camcorder that has a mic jack built in, and connect the shotgun right into the camcorder.
The mic doesn't have to be pre-amplified, or does it?
__________________
PlanetBoredom.net
Yegor Sak is offline   Reply With Quote
Old February 23rd, 2004, 12:18 AM   #7
 
Join Date: Jan 2004
Location: Stockton, UT
Posts: 5,648
I don't know the 55, and of course, it will depend on your camera, but much of the time while a preamp will nearly always improve sound, it's also not entirely necessary. And as you've learned, a preamp isn't always the best thing anyway. Good pre's aren't cheap.
__________________
Douglas Spotted Eagle/Spot
Author, producer, composer
Certified Sony Vegas Trainer
http://www.vasst.com
Douglas Spotted Eagle is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

B&H Photo Video
(866) 521-7381
New York, NY USA

Scan Computers Int. Ltd.
+44 0871-472-4747
Bolton, Lancashire UK


DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > The Tools of DV and HD Production > All Things Audio

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



All times are GMT -6. The time now is 09:25 AM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network