at wits' end "High measurement distortion" warning

[socbutter]

I followed Jeff Mery's YT videos to run subwoofer sweeps for MSO to do its magic.
Things I did after getting the "High measurement distortion" warning:

• Replaced all cables
• Ran multiples sweeps with different AVR Volumes and Sweep Levels
• Sweeps made in dedicated HT with double entry door
• Reduce Sub GAIN in MiniDSP2x4HD
• Configured WIN10 Audio Playback Devices per pages 7-22
• A Step-by-Step Guide (Rev 6.5, Dec 31, 2022)

I'm at an impasse and do not know what next to try or just ignore the warnings.​

Any help would be appreciated.​

​

 

[John Mulcahy]

The distortion does look high at low frequencies, but the measurements look OK to use for MSO.

 

[socbutter]

Thank you.

 

[sam_adams]

A few things you can do to get better S/N. Increase the stimulus level, increase the sweep length or both. Also, John made some changes recently to the distortion plots and recommended starting the sweep at 0 Hz for better distortion measurements. Another thing to do when making measurements is to make sure to reduce background noise as much as possible. Turn off AC and other noisy appliances and home systems.