Andrew,
This is great work. I’ve been super busy in RL and have not really being paying attention. One of the mods at SBAF pointed out what you are doing. I don’t think it was this video, but another one where you suggested a fuzzy zone target.
Reading around the Internets, looks like you are causing some trouble now with a “Resolve Target” LOL.
Anyway, the 1db/oct downward slope (at the listening position) is what is common in studios, mix stages, etc. There are variants of this like B&K AES 1970 which are more or less flat to 200Hz before the downward slope. Also, when speakers that measure flat on-axis 3 meters away are placed appropriate listening positions in decently treated rooms (or a normal living room with carpet and furniture), we will also see this 1db/oct downward slope behavior (at listening position). This is what I consider neutral. This is what I “train” my ears on.
The target I prefer to use is naturally what studios have in place. Naturally there will be variance, if they are using JBLs, Genelecs, ATC, Adam Audio, and even down to the specific speaker models.
This is why I prefer the 1db/oct slope or B&K (same thing but less low/sub bass), but I also like what you did with providing that zone which can accompany Harmon (preference research) and perhaps others (Audeze “house” sound).
Anyway, I wanted to clarify what you are doing. Basically applying DF comp on the 5128 and then plotting against proposed targets? Tempted to join the 5128 club and follow what you are doing. Thought it would be nice if we can converge on a method. More people taking measurements using the same method will lead to more comparable and understandable results for people at large.