Inconsistent measurements

[Tony Minides]

I am taking measurements using my soundcard

Scarlett 2i but I can't for the life of me replicate the same sweep reading identically if I repeat straight one after the other. I am trying higher resolution, more repetitions, higher sample rate but I am still getting different sweeps. Any ideas?

 

[John Mulcahy]

Looks like noise, would be easier to tell if you included the frequency axis. The camera icon at the top left of the graph makes properly formatted images of graphs. Have you selected the input channel your mic is connected to?