Thread: Could any of the following (...) cause static in speakers?

Hi. I've bought a new speakers recently, and they are pretty powerful, compared to the ones I've had. The old ones were from a market, we could say...

Anyway, I hear some sounds, not radio, it's like Morse's alphabet messenges, it sounds like that. Static, I think it's called in English. So I've tried to investigate a little, what could cause this sound:

A fridge ~3 meters away,
Antennas on the other side of the house, 2 satellites and one old (I live in kinda... undeveloped country...).

I found nothing else around, that could exceed any electromagnetical impuses, or something like that, which could possibly cause such things.

So anyway, could any of these things cause that sound?

are they hooked up when you hear this?

If the speaker cables aren't shielded very well, its easy to pick up other EM signals that can cause a bit of noise. It's also possible that the fridge is interfering, but probably through the house wiring if your speakers are the kind that plug an amp into the house's AC. The easiest way to test the refrigerator is to unplug it and see if you still get the interference.

You can do the same for the satellite system or other electronics. Just do it one-by-one. If you find the culprit, check the cabling for unshielded / poorly shielded conditions. Lots of things emit RF that can interfere with speakers, the most common that everyone is probably aware of are cell phones, which tend to have a distinct interference pattern when it rings or accesses the cell tower.

If your Speaker and Amplifier is not shielded good ,
Then just the AC current flowing through your house wiring can also cause that.

The sound might also be due to Non regulated varying current provided by the power supply to amplifier.

You may have a radio ham close by, usually what happens is the speaker cable acts like an antenna collecting radio waves, these are can then be 'demodulated' by the active components in your amplifier (such as transistor junctions).
This is called radiated susceptibility. If the interference is from the speaker cable the volume control will not affect it.

Another form of interference is called 'conducted susceptibility' where the interference travels through cables conncted to other equipment or the power supply such as the AC plug - this can be cured by a good quality mains filter.
With this case the volume control may affect the level.

A third form is from some defect within the sytem such as a part overheating, a dry joint, 'noisy' component. You could check this bby moving the system to a friends house and see if any interference of the same kind occurs.

If you can record the sounds and post them up somewhere it might help.

Turn the fridge off and on a few times thermostats can produce lots of interference.
Turn oher things off when using the amp - essentially try to elminate other things by trial and error.