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Thread ID: 90371 2008-06-01 01:15:00 Why do speakers hum static? beetle (243) PC World Chat
Post ID Timestamp Content User
674411 2008-06-01 22:51:00 Surely someone knows the technical answer for this.

If the hum is coming through the speakers, it's likely a bad/missing/loose ground connection on the signal input, or something wrong with the amplifier itself - or picking up interference from somewhere

Otherwise, inductors, transformers, coils etc can all make audible sounds if they are loose enough and the frequency going through them is in the human hearing range..

That is why I can hear my speakers' power transformer buzz sometimes - as it is running at mains voltage frequency (50hz)

You can get a good article on how this works here: www.psaudio.com

I can't be bothered writing it myself, plus I might get it wrong :o

In this case, if knocking them off the table and replugging them fixed the problem, then it was very likely a loose connection somewhere..
Agent_24 (57)
674412 2008-06-02 00:25:00 If the (Pale green?) plug to the speakers from the back of the PC is not fully inserted, sometimes it will give this effect.
(It is fairly cheap and easy to try this at home.)
R2x1 (4628)
674413 2008-06-02 08:54:00 Why do speakers hum static?
Because they are speakers, but if they were dancers they could hum mobile. :groan:
R2x1 (4628)
674414 2008-06-02 11:45:00 magic mejobloggs (264)
674415 2008-06-02 14:52:00 <removed for the usual reasons..by ME!, not a mod this time> SurferJoe46 (51)
674416 2008-06-03 11:32:00 The question is, is the humming coming from the speakers.... or is it from the mind?? :P rob_on_guitar (4196)
674417 2008-06-04 13:31:00 if its a smooth sounding hum, it is most probably mains or 2x mains frequency either inducing in the amp chokes/filters etc, or as other people have said, a loose or noisy mains transformer (vibrating transformer coils) if however it sounds sharp edged (similar to when you touch a signal input and get a prrrarp prrrarp sound from the speaker) i would suspect a dry joint, loose connection on the signal input line ground somewhere or a plug not fully in
your computer might have poor noise filtering on its sound card (on my old laptop you can hear interference from the hard disk and IRDA ports etc)
williamF (115)
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