One of the most common problems we see with measurements being uploaded to Tracebook is the VHF (very high frequency) response. If you upload a response that has a surprising slope down or up, the moderator is going to seek out a reference for comparison. You can save yourself some time by doing your own verification before measurement and upload.
The most common source of these VHF problems has been vertical aim and reflective surface. First, let's discuss vertical aim.
These easiest way to verify this is to play the game of hot & cold. Watch the magnitude response while you rock the speaker up and down to find the maximum.
This is not a guaranteed solution, though. If you still have doubts, please try one of the following methods.
Measure perfectly on-axis with the speaker on a table. Use that trace as an aiming target when you go back to ground plane. For more on this, please see line 250 of the measurement procedure.
Seek out a reference from the manufacturer. This is typically how a moderator is going to grade your measurement. If you look at the speaker's spec sheet or the GLL file and your measurement varies significantly, you can expect a moderator to have questions.
The other common problem is the reflective surface. If you have some suspicions that the carpet or stone you are measuring on is causing the problem then start with one of the two verification methods above. A possible solution is discussed on line 461 of the measurement procedure:
Please comment on this post with other ideas or questions. Thank you!