loss of high frequncies

[mrhairy]

Here's my problem. I have a track of white noise. Record a new 2nd track that uses the white noise track as its input.

Result:
The 2nd track doesn't have as much high end. When checking a spectum of the signal, it shows that frequencies greater than about 10k begin to get filtered out.

I have tried this with two different labtops with Audacity and Kristal with the same results. When I use a desktop, however, the two tracks are exactly the same and the problem is gone. I'm doing a project for school. To be honest, I haven't used a labtop very often for audio, only my desktop. So maybe someone knows a setting I should change. By the way, the labtops had windows 98 and 2000, and the desktop xp. Can some plese help me?
-Justin

 

[AGCurry]

Other than the obvious question of why you're recording white noise a second time...

Sounds like a problem with either cables or sound card.

 

[scrubs]

please describe the equipment you are using to record this white noise? i would also suspect the soundcard/converters as the culprit.

 

[reshp1]

I'm guessing here, but the laptops probably only have a "mic in" while the desktop has a "line in" and also a better soundcard. The "mic in" on the laptop is attached to a crappy preamp that doesn't have a flat high frequency response

 

[mrhairy]

I already have the white noise generated, so I'm just importing the file in. Then, for the second track I'm recording "what you hear", which is the white noise that I just imported. I'm not sure what soundcard is in the labtop (I'm renting out from my department, I think it was a EXX Malesto???) But anyway the only reason I'm recording it again because I want to make sure the computer is actually outputting a true white noise signal to the system I'm testing, so I'm just recording the output of the soundcard. It's not a true white noise signal with a cuttoff frequency at 10k!