Some problem with electrical interference from my power source

[porkie72]

I am currently using a Swans D1010IV speaker set.

I have noticed occasional low frequency humming sounds coming from my speakers. I have tried to isolate the problem and realised the root cause is most likely from the power input as the humming will persist even when I have unplugged all inputs and turned off my pc.

Is there some special electrical cable I should get to minimise this random distortion?

 

[mypillowtalks]

Maybr u can try shifting your speaker set away from the ac line. Seems like u r talking about the 50hz hum.

Another common hum is caused by ground loop hum.

 

[valueair]

As mypillowtalks said more likely a 50Hz hum from power supply or ground loop.

Try a different power adaptor that has a better line filter.

http://electronics.stackexchange.com/questions/2122/mains-hum-filter

Or add a RFI filter yourself if you a DIY person.

For 5A
http://www.newark.com/tyco-electronics-corcom/5vr1/rfi-power-line-filter-5a-700ua/dp/52K3857

10A
http://www.newark.com/tyco-electronics-corcom/10vr6/rfi-power-line-filter-10a-700ua/dp/52K3303

 

[wwenze]

We're dealing with a 2-pin power plug speaker that has hum when nothing is connected to it.

The hum is either self-produced or airborne (and gets picked up because of poor shielding). Nothing you can do about.

Sometimes the sound goes away when connected to a source. (Tech tidbit: This is because airborne EMI generates a higher voltage when load impedance is high. An audio out connection pin shows up as a low impedance.)

Then, mechanical imperfections can cause noise to appear on and off too.

All these points to speaker design or build quality which frankly you can't do much about.

 

[porkie72]

Thanks for all the advice.

Just to be safe, I have sent the speakers back for RMA.

I just find it peculiar as to why the humming is reduced to almost inaudible when I turn the treble knob to maximum.

Also the decibel level of the hum is not affected by the volume knob. Meaning to say it still hums even when I put the volume to zero.

 

[porkie72]

Oh I went to google 50hz hum and that's not the sound I'm hearing. I will upload the sound when I get back to my desktop. I sounds more like a beep tone.

 

[porkie72]

https://www.youtube.com/watch?v=5DMoAJf0s24

this is how the beep sounds like. sorry u will have to turn ur volume high to hear it

 

[wwenze]

Try YouTubeing a 10 kHz sine wave. This tends to be intermittent and airborne. And tend to appear more often at certain time of the day.

Design issue. The behavior with regards to volume knob position isn't uncommon.

You can try playing with the grounding of your source and amp (in the speaker) to try to get rid of it. You may end up having more or less noise. Then you'll accept what can and can not be achieved.

 

[porkie72]

im really keeping my fingers crossed that the problem will go away when the set returns from the service centre.

as u have mentioned, i guess there is no way i can purchase a 2 pin fig-8 which is able to shield off the interference as the root of the problem is most likely airborne and not due to noise in the electrical input

 

[porkie72]

guess i wasted money buying ferrite sleeves for the cables