Will input clipping give false measurements??

[Dirt9]

Two measurements,everything the same other than the volume using a cross spectrum umk-l,

 

[Dirt9]

obviously there would be a decibel change but why a slope difference?

 

[John Mulcahy]

Yes, clipping gives false measurements. The first measurement was very heavily clipped, so the actual levels could not be captured. The measurements align well out of the clipped region.

 

[Dirt9]

Thank you very much for your response.just to be clear the green was taken with the master volume at -20 and the red was at-10.