Mysterious White Noise

[zepelini]

Hey all. I've checked other white noise posts, but can't seem to find a solution for this...

I'm using a AT9941 running through an Edirol UA-4FX to a mac mini. When I try to record just silence, I get quite a lot of high frequency white noise (hiss).

- If I completely cover the microphone, the white noise sounds exactly the same, so it's definitely not some kind of atmospheric sound.

- If I use some of the effects on the edirol (e.g. delay / fx voice), it also effects the white noise. So it's being introduced before it reaches the mac/edirol.

I guess the first thing I should ask is.. is it actually possible to record silence and get a reasonably quiet signal? After searching a bit, I found this youtube video which compares a couple of microphones: (AT demo starts at 0:40)

https://www.youtube.com/watch?v=AydirkDHmLk

In this recording you can hear the constant white noise which is similar to mine. Is there something I can do to reduce it? (from the signal that is, not by using post-fx noise removal techniques).

Any suggestions would be appreciated!

-z

 

[Dogbreath]

First thing I would look at is the gain (trim) setting.

How high are you cranking the input signal?
Start with the very first "volume" adjustment you can make. They may call it "gain" or "trim". Back that off and see if the hiss goes away.

 

[moresound]

Now this microphone is meant for a video camera and is a stereo microphone with a mini TRS connector!
How are you hocking it up?
And does it need Phantom power? If so I don't think that this will work all that you will get is a bunch of mysterious white noise.

 

[zepelini]

Hey, thanks for your replys.

Dogbreath: The hiss is pretty strong -- I can set the input on 25% and still hear the noise (at which point the sound I actually want are too quiet)


moresound: ha, I didn't know this microphone is designed for cameras. This is why I feel better posting in the noob section.

The Edirol has two sized plug holes for a microphone. The small one is labelled 'MIC (plug-in/powered)' and the big one (which I tried with an adaptor) is 'GUITAR/MIC', with an additional switch which lets you choose between the two. The mic has its own small battery, and the edirol is powered just by usb.

I get the same results from both mic ins, but I just discovered if I use the guitar/mic one (large sized), I get considerably less noise. About 20%. It's much better but still not quite useable.

EDIT:
Here's a picture of the Edirol interface