Crackling Buzz

Whenever I turn up the onboard sound from Windows, I get a buzzing/crackling
sound. I updated the MB's Bios and the Realtek AC97 Drivers to no avail.
Anyone know what it could be?

Thanks

 

What is your motherboard ?

Paul

 

Do you get a buzzing/crackling sound when there is no signal (i.e.
volume high but nothing playing), or are you referring to signal distortion?

The former suggests a poor connection or grounding problem, while the
latter suggests a software problem (BIOS PCI latency timer setting can
cause it, for example).

P2B

 

You guys are fast to reply - Thanks!

The Motherboard is a P4S8X-MX

And, yes I get the buzzing sound when the volume is med-high but nothing
playing. It is louder when plugged into the front audio input than in the
rear.

Sounds like it may be the grounding problem. Any suggestions to get rid of
that? Will installing a (new) soundcard take care of it (and disabling
on-board sound)?

 

There's a hint ;-)

I'd try disconnecting the front audio ports (all of them) from the
motherboard. If that fixes the rear port, you know the cables to the
front are inadequately shielded or part of a ground loop.

Quite possibly, but also quite possibly not. Better to understand the
problem before throwing money at it.

Other information that might help:

What does your external audio system consist of? Is it externally
powered? From the same outlet? Have you tried headphones?

P2B

 

In the electrical standard for your country, do you have a safety
ground ? In North America, newly built homes have three prong plugs,
and the third prong is a safety ground (earth). Older homes have only
two prongs, and that can occasionally cause problems.

Computers typically have PI filters where the AC enters the power
supply. One of the side effects of the PI filter, is it dumps a
small amount of AC from the power line, into the safety ground.
If, for any reason, the connection to the safety ground is open,
the computer case can become electrified. I'm guessing there is
a potential mechanism there, to introduce "AC hum" into an audio
circuit. Especially if the computer and the stereo are on separate
AC circuits or AC wall sockets, and one of the sockets is defective
or is behaving differently than the other socket.

Also, one of the hardest things, in diagnosing audio problems, is
in the terminology used to describe the problem. Buzzing, popping,
and crackling mean different things to different people, so it is
sometimes hard to know just exactly what a person is hearing.

If you had a way to record the sound and could post it somewhere
for download, that is one way to get a good description of the
symptoms.

Paul