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Reducing Intereference in Your Speakers?

Posted by Cliff on from the ditching-that-annoying-hum dept.

PolicyWonk asks: "I just bought a new stereo, a Sony CMT-EP707, into which I intend to plug my laptop when watching DVDs, and my iPod when listening to music. When I first turned the stereo on I was horrified to hear interference from a local radio station, as well as a general hum emanating from the speakers. The hum and the radio emissions are audible even when the stereo's volume is set to 'min' and irrespective of what setting the stereo is on (i.e. Tuner, CD, or MD), or what input is (or isn't) plugged into the stereo. (I have tried my laptop, iPod, and no input). That means that during a quiet pause in a movie, or the intro to a song, this background noise is clearly audible. No amount of moving the speakers around the room, or plugging the stereo into different grounded outlets seems to fix the problem. I've checked my outlets, and they appear to have a ground connection, but I live on the fifth story of a circa 1900 apartment building in Manhattan, so it's anyone's guess what happens to the wires once they are in the walls. Anyone have any good solutions for reducing or eliminating interference from nearby radio sources?"

3 of 59 comments (clear)

  1. RFI chokes by Kizzle · · Score: 5, Insightful

    A fairly cheap method of reducing radio/TV signal interference involves just the opposite of "grounding". Go to your local Radio Shack store and get a bag full of "RFI chokes". They have several different shapes and sizes. They snap together and are supposed to be placed over wires and interconnect cables in order to prevent RF currents from flowing along the outside of the wires. You don't have to disconnect anything to install them. Just place them over the cables and snap them closed.

    --
    Hacker Media
  2. Grounded Outlets by Anonymous Coward · · Score: 3, Insightful

    You know you can buy a ground tester at a hardware store, right?

    I don't know but your landlord might be legally required to supply you with grouned electrical outlets.

  3. Ground Loop Isolator by Gormless · · Score: 3, Insightful

    I had the same problem while trying to play DVD audio from my PC to my home stereo.

    I bought an "Audio System Ground Loop Isolator" (# 270-054A) from Radio Shack for $20CDN... problem solved.

    Here is a link to some info on the problem and possible solutions.