strange random noise in speakers

[fiksal]

I've asked this question before, but now it seems a bit different.

First time it happened, I thought it was my sound card, and buying a Creative sound board did help that issue. The crackling noise is back however, on a new computer.

What's different this time. It's rather loud, lasts about 1-2 min and usually seems to happen in the evening at random time(s).


During one of the crackling episodes I tried both disconnecting the three output wires from PC that go into my sub (it's a 5.1 system) as well as disconnecting the power cord and plugging into another outlet.

What I learned is - outlets dont matter, and the noise stays even if sound cables are unplugged.

So... any advices?

Are the cables acting as antennas? Is something wrong with the sub now?
If it's the antenna thing, what can help with that? I dont suppose electrical tape does anything at all, does it?

[Xenon_Slayer]

I remember my friend saying that they could hear all kinds of stuff coming from speakers even if they were unplugged because of a nearby radio transmitter. I myself have heard some faint speaking coming though while I'm on the PC.
Crackling though could well be the power supply having a hickup. I expect speakers are one of the easiest devices to notice it on.

[fiksal]

I remember my friend saying that they could hear all kinds of stuff coming from speakers even if they were unplugged because of a nearby radio transmitter. I myself have heard some faint speaking coming though while I'm on the PC.
Crackling though could well be the power supply having a hickup. I expect speakers are one of the easiest devices to notice it on.

Power supply of the PC or whatever's in the sub?
The power supply in PC is pretty beefy. And the noise is still there when Sub is plugged into different wall outlet.

[felter]

Could be a bad connection or some sort of short.

[X2-Eliah]

Have you tried if it happens on headphones? then you could know if it's passed in the signal or originating in the speakers.

[fiksal]

Have you tried if it happens on headphones? then you could know if it's passed in the signal or originating in the speakers.

hard to catch it sometimes,
last I had the problem similar to this, I didnt hear it in headphone speakers, but I'll try to test this again.



small update:

nearby dryer after it finishes does a weird series of short noises, that too get picked up by speakers as crackling static. That noise is very short however

[amtct]

This

I remember my friend saying that they could hear all kinds of stuff coming from speakers even if they were unplugged because of a nearby radio transmitter.

and this

nearby dryer after it finishes does a weird series of short noises, that too get picked up by speakers as crackling static.

should not happen in a non-haunted house

[X2-Eliah]

Oh, well then there's no mystery. I bet it happens just at the time when the snake-headed alien overlords fly over your house, causing electromagnostatic interference from their ionized maglev spacetrain.


Seriously though.. Could be your speakers are just plain not monitored properly and pick up EM field changes. (or was it ES field? can never recall)

[fiksal]

Seriously though.. Could be your speakers are just plain not monitored properly and pick up EM field changes. (or was it ES field? can never recall)

alright, how do I check for that?

[X2-Eliah]

Use different speakers, or better yet headphones/earbuds, for a day or two instead

[amtct]

Use different speakers, or better yet headphones/earbuds, for a day or two instead

Call a priest ...no ,better call the pope and a priest *.That house is haunted.
Have you thought to open the window?Some spirits like to exit the window

*Just in case there are kids on your street when you call the pope you should also call a priest ....you never know when a blind date can ruin your "remove the spirit from my house" program

[Morkonan]

Have you tried if it happens on headphones? then you could know if it's passed in the signal or originating in the speakers.

hard to catch it sometimes,
last I had the problem similar to this, I didnt hear it in headphone speakers, but I'll try to test this again.



small update:

nearby dryer after it finishes does a weird series of short noises, that too get picked up by speakers as crackling static. That noise is very short however

Sounds like you have a shielding problem with your speakers, their cords or maybe even the dryer.

Do you have very long cables for your speakers? Try using shorter ones or take up the slack in them and put a rubber-band around the resulting bundle. You might also want to double-check to be sure your dryer doesn't need servicing.

[jlehtone]

I remember my friend saying that they could hear all kinds of stuff coming from speakers even if they were unplugged because of a nearby radio transmitter. I myself have heard some faint speaking coming though while I'm on the PC.

Faint russian speaking here, from cheap Logitech 5.1. Have changed speakers (and soundcard) since.

I tried Auzentech Forte that was broken with those 5.1. Continuous crackles. Eventually I had just the Forte on my desk -- not in PC -- and plugging speakers started the noise (so no power in card, just in the speakers). Shorting to ground on the connectors of the card, it was.

[Winter Dragon]

If you have a microphone connected to the computer, make sure it's muted in the sound controls or push to talk. I know it seems like one of those 'no-brainers' one always checks, but that happened to me last year.

[fiksal]

I'll try tie the wires up, they are indeed quite long.

If you have a microphone connected to the computer, make sure it's muted in the sound controls or push to talk. I know it seems like one of those 'no-brainers' one always checks, but that happened to me last year.

I have the crackling noise when speakers arent connected to the PC at all

I remember my friend saying that they could hear all kinds of stuff coming from speakers even if they were unplugged because of a nearby radio transmitter. I myself have heard some faint speaking coming though while I'm on the PC.

Faint russian speaking here, from cheap Logitech 5.1. Have changed speakers (and soundcard) since.

I tried Auzentech Forte that was broken with those 5.1. Continuous crackles. Eventually I had just the Forte on my desk -- not in PC -- and plugging speakers started the noise (so no power in card, just in the speakers). Shorting to ground on the connectors of the card, it was.

Faint Russian? nice

[xeon_1]

I'll try tie the wires up, they are indeed quite long.

If you have a microphone connected to the computer, make sure it's muted in the sound controls or push to talk. I know it seems like one of those 'no-brainers' one always checks, but that happened to me last year.

I have the crackling noise when speakers arent connected to the PC at all

Then its probaly something to do with the power supply and or power circuitry in the subwoofer.
best case just replace the powersupply
Worst case need a new print board in the subwoofer are replace/resolder the guilty component.

[bobxii]

What you've got is a crappy power signal (like, the wall outlet) combined with a poor power input filtering setup on your speaker system. The dryer thing and the fact that the system works most of the time pretty much confirms this - other devices on your electrical loop are dumping harmonics into the line, and it's getting pushed onto the power rails of your speaker system and coming out as crazy static sounds (the sound is ELF harmonics fed into amplification circuitry the wrong way - a digital clipping/overdriven sound).

If you want to fix it, look into a power conditioning device (typically used for high-end sound devices, ironically), or hunt down the device that's causing the issue. If I were you, I'd hunt around for high-power gas-discharge lamps, such as those used in security lighting (typically come on in the evening, yes?). Worn out magnetic ballasts are known to produce massive amounts of wideband noise when they turn on - it drives amateur radio guys nuts.

Honestly, I'd be suspicious of a neighbor growing marijuana using grow lamps (aka gas discharge), due to the regularity and timing of the noise - possibly using your electricity! It wouldn't be the first time somebody's equipment interfered with the electrical grid.

*edit* fed into...

[Morkonan]

What you've got is a crappy power signal (like, the wall outlet) combined with a poor power input filtering setup on your speaker system. The dryer thing and the fact that the system works most of the time pretty much confirms this - other devices on your electrical loop are dumping harmonics into the line, and it's getting pushed onto the power rails of your speaker system and coming out as crazy static sounds (the sound is ELF harmonics fed amplification circuitry the wrong way - a digital clipping/overdriven sound).

If you want to fix it, look into a power conditioning device (typically used for high-end sound devices, ironically), or hunt down the device that's causing the issue. If I were you, I'd hunt around for high-power gas-discharge lamps, such as those used in security lighting (typically come on in the evening, yes?). Worn out magnetic ballasts are known to produce massive amounts of wideband noise when they turn on - it drives amateur radio guys nuts.

Honestly, I'd be suspicious of a neighbor growing marijuana using grow lamps (aka gas discharge), due to the regularity and timing of the noise - possibly using your electricity! It wouldn't be the first time somebody's equipment interfered with the electrical grid.

Excellent post and after I read it, I agree it's the most likely cause of the problem!

Outstanding diagnosis! ++!!

[X2-Eliah]

Does that even apply if there is a computer (psu, cpu, motherboard etc.) inbetween the outlet<->speakers chain?

[Tracker001]

Yes it can . You want to put the power conditinor before the computer and the speaker if those are powered .

You can get decent and not tooooo one expensive from music stores .

There should be a Guitar center where your at .

Best would be to get an isolation transformer before the computer .

Isolation transformers offer complete line isolation, continuous noise filtering and enhanced common mode surge suppression.