Abyss is quite right, the measurements are borked.
Let me remind you that ASR measured Stax headphones without a seal because they are "earspeakers" (decades old Stax marketing term), when in reality they require a super tight seal to reproduce the correct, intended by Stax bass balance. Of course, measurement without seal showed no bass, and then "deficient bass" was claimed without further investigation. Similar levels of sloppiness with Abyss headphones.
FWIW, I've heard their top model (but the first version, not the newer ones), and I think it has epic bass for a headphone, in fact, too good, the mids and highs sounded much worse by comparison. That headphone setup was high end bass > mid fi midrange > low fi treble, IMHO. They probably "fixed" it with the newer iterations, or at least that's what the user reviews say. I have not heard Diana, but I highly doubt that bass is sub par or that it sounds distorted.
Do not waste time with ASR, they barely take time to double check things (not even going to mention listen to the products they critique). Those kind of websites are not that much different from places like 4chan or some subreddits, they are full of oversimplified bile parroted to lure insecure people that needs to feel "part" of something.