PC speakers making a faint clicking noise at about 2Hz

[boylesg]

Would it be worth making an RC filter (**broken link removed**) and pass each speaker channel through 2 such RC filters?

Filter

Vin(s)→ **broken link removed** →Vout(s)

[SIZE=-1][SIZE=-1]R = 160Ω
C = 470uF

[/SIZE][/SIZE]

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Actually it seems to be an RF source in the PC box or the LCD screen. Moving the speakers away from the box and screen etc seems to result in the clicking noise stopping.

I wrapped the speaker with the amplifier in it with alfoil and it seemed to stop the clicking sound coming from that speaker but it is still coming from the other speaker. I suppose the RF might be coming through the cable joining the two speakers. Wrapping the audio cables in aluminium tape might do the trick

 

[godfreyl]

Would it be worth making an RC filter (**broken link removed**) and pass each speaker channel through 2 such RC filters?

R = 160Ω
C = 470uF

You're joking, right? or you just didn't think this through properly?

 

[BradtheRad]

1.

2 Hz does not seem like it would come from the screen. Unless your screen refreshes at 60 Hz and something else is happening at a rate of 62 Hz. Then there might be an interference tick at 2 Hz.
Any combination of events which are 2 Hz difference in frequency, could cause it.

2.

Do you have a wifi card in the computer? Perhaps it is sending out rf pulses at 2 Hz because it is set to detect guests on its network? Can you try turning off your wifi?

Also try disconnecting peripheral devices, one at a time, to see if the ticks stop.

3.

I believe there are sound cards which can detect what device is plugged into the audio 'out' jack.
Suppose that is sending out ticks at 2 Hz in order to detect a device?
Can you try adding a resistor, say 50 ohms, across the plug which goes to your speaker amplifier? This will reduce the amplitude of all signals going to your speakers. But it might tell the sound card to stop the ticks.

4.

A ground loop may be the problem, although that typically causes 60 cycle hum.
I got hum in my system until I disconnected the cable TV. With a little more experimenting I found I only needed to stop the ground rings from contacting. It was okay to leave the tiny center wire connected to the jack.

 

[boylesg]

You're joking, right? or you just didn't think this through properly?

I am a beginner godfrey so you tell me. I am just making a bit of a guess from the bits and pieces I have picked up over the last 12 months or so.

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1.

2 Hz does not seem like it would come from the screen. Unless your screen refreshes at 60 Hz and something else is happening at a rate of 62 Hz. Then there might be an interference tick at 2 Hz.
Any combination of events which are 2 Hz difference in frequency, could cause it.

2.

Do you have a wifi card in the computer? Perhaps it is sending out rf pulses at 2 Hz because it is set to detect guests on its network? Can you try turning off your wifi?

Also try disconnecting peripheral devices, one at a time, to see if the ticks stop.

3.

I believe there are sound cards which can detect what device is plugged into the audio 'out' jack.
Suppose that is sending out ticks at 2 Hz in order to detect a device?
Can you try adding a resistor, say 50 ohms, across the plug which goes to your speaker amplifier? This will reduce the amplitude of all signals going to your speakers. But it might tell the sound card to stop the ticks.

4.

A ground loop may be the problem, although that typically causes 60 cycle hum.
I got hum in my system until I disconnected the cable TV. With a little more experimenting I found I only needed to stop the ground rings from contacting. It was okay to leave the tiny center wire connected to the jack.

No wifi card in the PC but I do have an ADSL modem with a wireless connection above - I presume this would be wifi.

It seems to be peculiar to a particular set of speakers and the volume of the tick changes when I move the speakers around on the desk.

In the end I just changed the speakers.

 

[godfreyl]

I am a beginner godfrey so you tell me.

OK.
You proposed a 2'nd order low pass filter set to 2Hz. That would remove the ticks nicely. It would also remove all music, speech, and any other sound you want to listen to.