Humming/Hissing Sound on Speaker

Any audio amplifier will have a rated signal/noise ratio, which might be given in decibels (dB).

What is happening is that the ear is so close and so well-coupled to the speaker that the noise level is becoming audible at times.

The only real solution is to replace the amplifier with one with a higher signal/noise ratio.

Thank you for your response PWSlack.

So, it means that my speaker is ok or normal sir? Except (as you mentioned) in its specification of signal/noise ratio.

My speaker is active speaker (the amplifier is inside subwoofer), so it is very difficult to change the amplifier with the greater signal/noise ratio.

Thank you for any explanation.

"2. I have given grounding cable (attach cable on one of the speaker bolts and connect it to nail on the wall), but the disturbing sound never stops."

A) This is NOT a ground, unless your wall is made of some conductive material, and is connected to earth ground! If you have 3-wire outlets, the screw holding the cover plate in place should be a good ground. B) it is unlikely that grounding the speaker frame will make a significant difference. Grounding the correct contact on the amplifier might. C) Most speaker frames are painted; you must scrape the paint off where the ground wire contacts painted metal. The same is true of anodizing on aluminum.

To me, there is a big difference between hiss and hum. Hiss is a high frequency noise with no obvious single frequency. All transistors used to have some hiss - I'm not sure if that is still true. Hum is a low frequency noise, usually at the power line frequency or twice the power line frequency. Years ago, hum commonly meant failing capacitors in the power supply, but it could also result from poor grounding.

Good luck...

Try turning the volume control on the speakers down to a lower level.

Then adjust the volume level on your computer louder until the volume level of the music you are listening to is satisfactory.

The add on speaker system will only amplify the signal you give it.

If the signal from the pc is low and poor then it will reproduce that poor signal.

If the signal coming from the pc is loud and strong... well you get it!!!

Regards.

There are some unaviodable sources of noice in eectronic components which have some effect on producing sounds [noise] e.g. thermal agitation in atoms etc etc only for researchers & designers but is info for music fans.

Others are Inducted or cnducted signals and can be minimised not altogether removed.

And Hi Input impedance also may be reason to produce Hum.

And Nail in a wal is not EARTH /Ground; but a floating wire working as an antenae.

You need to prove what is defective, if anything.

1. Disconnect the "audio system" from the PC, and take it to another room.

2. Connect an iPOD (or any MP3 player) to it, and listen to it under several volume levels. If it does that well, it is NOT the "audio system".

3. Now connect a simple stereo earphone set to the same audio output on your PC that you were going to use with the "audio system". If that works well, then:

4. You have a ground loop, or a serious RF interference problem in your computer system.

5. There are a couple or three audio outputs from most PC's. Try all of them.

Thank you for all replies..

I don't have any ipod, so I test it to my laptop (battery-powered), the humming (if louder) and the hissing (if silent) still no changes. But i still tested in the same room. Ok will try it to test my speaker to another room.

Oya maybe this one coul help you analyze the problem.

Actually i used wrong electrical socket. The electrical plug of my speaker is just like the following picture.

But i plug it into this kind of socket (British standard)

Could this thing make the humming & hissing sound? I haven't tried to plug it into the right socket like this

I know this is stupid plugging it into wrong socket, but i could not find the right socket so far. So i used the British socket (and luckily it is well-fitted, i know there is must be untouched surface inside because of the unmatched shape).

I need your comment please. Thank you very much.