View Full Version : interference in sound and other things

03-10-2002, 12:54 AM
[i'm a musician with a bit of a physics background, and lots of math]

i recently got a nice 5.25 frontend 7-band eq that i intend to use for recording. it dawned on me as i'm listening to some static right now [from it's output through my headphones] that, even if it was through my original speakers, i still get a hum or some static. i used to use [or not use, actually] another poor-mans front-end that picked up a lot because it wasn't grounded correctly or something [i decided to just get the real stuff and not have to bother with trying to make my own eq, that'd be really messy in the confines of a 5.25 drive bay, and expensive]... anyways, you get this hum even from your sound-card's output, and it is really bothersome... is there anything i can do to fix this? [i'm guessing if i buy a really expensive audigy-class sound card that'll do the trick... or maybe some new speakers or headphones with a higher tolerance] also, if i want to use the output from my amp, is setting the intensity to 1 going to give me a one to one ratio in signal intensity? [it has distortion, and i have another amp with reverb that i'd want to use. and i could bother to buy a pedal, but i'm still thinking...] thanks for all your input i appreciate it.

03-10-2002, 01:27 AM
okay i changed the levels a bit, and it helps a little, but there is still something keeping it from being clear.

03-10-2002, 01:32 AM
does the mute all option stop the noise?

03-10-2002, 01:35 AM
Yes, so I'm guessing it's in the device I got, I'll check some other sound channel tweaking to localize the problem, thank you.

03-10-2002, 03:22 AM
>i'm listening to some static

English is not my first languange, can you explain what you mean by this?

In case you mean there's no really sound, an explanation could be:

It could be that you're having a finite wordlength problem. The soundcard uses N bits to represent audio-data. When the volume is high, many bits will be used to represent the data. When you turn the volume low, less bits will be used. When the volume is very low, just a few bits, perhaps 1 bit, will be used. In case of 1 bit, there is a blockwave, which is a constant signal and which sounds like a low sinewave.

03-10-2002, 03:56 AM
Static is background noise

ie: when you turn on your TV on channel 421, it's just a load of black and white dots.

That's static

03-10-2002, 04:14 AM
Thanks Brian.

So if I understand well, this noise is always present, even if you turn the volume up?

Some systems do always add a little background noise, this is to prevent from finite wordlength problems. If you are listining to a piece of music, sometimes at the end the volume is going very low. So very less bits will be used to represent the data and the wave approximates a blockwave. To solve that problem, some noise is added to make a volume a little higher so that more bits are used and the sound doesn't sound like an almost blockwave.

To me it would be logical if the noise would be heard when the volume is turned up, but perhaps there's something strange and the noise is also amplified.

03-10-2002, 12:24 PM
well try muting any channels that you not using or some you are sometimes, the noisiest are the line-in, the microphone, and strangly the CD audio on some drives.

03-10-2002, 01:46 PM
What kind of setup are you using?
I have quite a bit of experience in this area.
I'm guessing a large part of the problem is the quality of the equipment but there are things you can do to get the best performance out of them.