01-16-2009 09:26 AM - edited 01-16-2009 09:28 AM
I'm trying to a SNR measurement from an audio signal in LabVIEW. However, I cannot measure SNR correctly. After investigating I found that sometimes I can have a higher THD than THD+N. As I believe that this is not possible there should be a mistake somewhere in my VI.
Here the analysis part of my VI :
And sometimes, here is the result when distortion is high :
Any idea for resolving this ?
Solved! Go to Solution.
01-23-2009 06:44 AM
01-23-2009 10:23 AM
Bon soir Alexandre,
are you using simulated input signals and could post your signals? How many harmonics are you calculating?
01-26-2009 03:26 AM
No, I'm not using simulated input signals but audio input signal from a usb sound card.
The Distortion measurement VI is set to calculate 20 harmonics.
Thanks for you help.
Have a nice day.
01-26-2009 04:30 AM
It seems to be resolved now. The problem could appear when audio acquisition was too short (under 50 ms).
If audio acquisition is long enough then THD+N is always higher than THD.