Measured Frequency Sweep Output level varies

[texbychoice]

Using REW ver 5.30.1. Recently monitored waveform output from Laptop soundcard as frequency manually swept in REW. The P-P voltage varies up and down as the REW Generator frequency is manually swept from 20 Hz upward. Would expect the P-P voltage to remain constant regardless of frequency. Otherwise, how can any REW measurements be accurate? Is this REW or a soundcard issue?

 

[John Mulcahy]

Soundcard, could be bandwidth limitation or some monitoring active. Running a soundcard cal would show either, if the laptop has a line input to use.

 

[texbychoice]

Soundcard, could be bandwidth limitation or some monitoring active. Running a soundcard cal would show either, if Tue laptop has a line input to use.

Thanks, gives me troubleshooting ideas.

 

[texbychoice]

Sound card "enhancements" option the problem. Thought that was permanently off. Latest Windows 11 update apparently turned back on since that is the only recent change. Thank you Microsoft!