09.11.2007 12:00 AM
Audio Hum: Causes and Solutions
In virtually every television environment audio hum can be a problem, either in a studio or out in the field. Even digital audio becomes analog eventually.

Solid system design work can make the instances of hum minimal, but it will show up eventually.

The most common causes of audio hum include unbalanced cabling, long cable runs, audio equipment connected between venues with separate electrical panels or services, poor electrical wiring, or interference from other equipment. Sometimes, the cause is never known, you just want it to go away.

Whether you are in the field or in the studio, the solutions are typically the same. First, make sure that the hum is not just in your monitoring circuit. It would still need to be cleared, but your product would not be suffering.

Next, check all of the connectors for proper pin-out and integrity. This task is made much easier if you use connectors that come apart quickly and without tools.

Try to consolidate your electrical connections to as few different receptacles as possible (while taking care to not overload circuits). Don’t be afraid to use extension cords to accomplish this. Often, using a three-prong to two-prong AC adaptor will alleviate hum. However, proper care must be taken with regard to safety.

Finally, when wiring balanced audio, it is a common practice to leave the shield disconnected at the signal destination. Don’t be afraid to “lift the ground” to see if this helps.


Comments
Post New Comment
If you are already a member, or would like to receive email alerts as new comments are
made, please login or register.

Enter the code shown above:

(Note: If you cannot read the numbers in the above
image, reload the page to generate a new one.)

No Comments Found




Tuesday 03:07 PM
WMUR-TV Says FAA Drone Rules Preclude ENG
The FAA’s current rules and proposed ban on flight over people, requirement of visual line of sight and restriction on nighttime flying, effectively prohibit broadcasters from using UAS for newsgathering. ~ WMUR-TV General Manager Jeff Bartlett

Sue Sillitoe, White Noise PR /   Friday 11:15 AM
DPA Microphones Expands Its d:facto™ Vocal Microphone Range
Wall Street Communications /   Friday 04:20 PM
SMPTE 2015 NAB Show Preview

 
Featured Articles
Discover TV Technology