I went and compared a bunch of my gear to make my own technicality test playlist.
Anyway, you should temper your expectations for $30 IEMs and be very skeptical of audiophile hype trains. No manufacturer is going to leave money on the table by charging that little for an IEM they know sounds high-end given how absurdly deep people's pockets go in audio land, although you should be warned that many of them do overestimate their products' quality and overcharge.
Try playing with how the Anandas are positioned and angled on your head. The cups are big with the pads being angled, so it might take some experimentation to find a good spot. Egg-shaped Hifiman planars seem to be quite sensitive to that, and even the $2,000 ones frankly sound on the level of $100 bleh-fi (comparing the HE1000 V2 with the SRH840, to be specific) if you don't get it right.
"i do not know what any of the terminology i am using actually means but will choose to offer my enlightened commentary on it anyway"
t. the most intelligent headphones subreddit poster
"tonal effects are a meaningless audiofool myth. so is timbre and things sounding enjoyable"
t. biggest brained arr headphones user
If you want an example, think of a recording of someone playing a low piano note. On something with thicker note weight, you might hear a full-bodied "DUN!", with emphasis being placed on the initial part of the note that makes it sound like the key is being struck more heavily. On thinner-sounding gear, you might hear a plain "DUN!" without the emphasis, making it sound like it's being hit more weakly. Measurement-wise, it would generally be associated with the upper/lower midrange balance being skewed towards the lower mids. V-shaped/Harman IE stuff will tend to sound thinner.
If you don't build your self-identity around your consumer purchasing choices, some light roasting centered around your consumer purchasing choices won't be a problem. If anything, DMS is being far too mild towards Sennheiser basslets and others of such subhuman ilk. Speaking as an HD800S owner, unironically liking the HD800S is the being 4'11" with a Peyronie's micropenis of musical enjoyment tastes
Find a parametric equalizer for more fine-grained control and try adding a 5 dB peak at 4 kHz, Q 2.0. Make sure to set the preamp to -5 dB as well. Connect your earphones to your PC and set up Equalizer APO/Peace GUI if you need to. If doing that makes the Momentum sound better, the issue is that you don't like its tuning.
Before anything else, I would start with the basics and try to make something that can reliably describe the overall sound signature of a headphone based on its graph. As is, the execution seems wrong on many levels.
You should not be examining portions of the frequency range solely in isolation, as bass/midrange/treble exist relative to each other and each affect how the others sound, you should be aware of how the measurements are being compensated, you should know the limitations and quirks of various measurement setups, you should 100% not be taking MiniDSP EARS treble measurements at face value regardless of how it's calibrated. Even if the AI were not hallucinating a peak at 10 kHz, "a peak at 7 kHz followed by a sharp dip and a peak at 10 kHz" describes what the pinna notch might look like on a typical GRAS rig. As questionable as AutoEQ may be for actually improving sound, its measurement database would be a much better means of sourcing standardized graphs than arbitrary user-uploaded images.
You need to use your listening impressions of the headphones whose FRs you're running through this program as a sanity check to ensure it isn't spouting nonsense. There is no getting around making the effort to correlating FR features to what you are hearing in reality if you don't want the output to be a crapshoot. Assuming you wrote the Headphonesty review this graph originates from, you yourself are calling the H1H's midrange mediocre at best and the treble subdued.
The way Rtings attempts it is an interesting metric but not one I'd take overly seriously. Ananda and HD800S being ranked next to each other is just lol
Electrical impedance is like resistance but with AC electrical current (flows back and forth, which is what creates vibrations in headphones to generate sound) instead of DC current (flows in one direction). Electrical impedance can be different for lower frequencies (e.g. headphone bass) and higher ones (e.g. headphone treble).
Headphone/earphone makers account for this when designing gear. If an amplifier has a high output impedance, it adds impedance, potentially skewing the ratio and, thus, the sound. That's why you generally want low amplifier output impedance, though some headphones can sound better with high.
David D. and Justin K. already wrote a very influential paper on exactly the topic of your post back in 1999
No fully agreed-upon definition for either of these as far as headphones go, especially not for the latter. Saying all you have to do is accurately simulate human HRTF and PRTF is easy, actually doing it is not. Trying to jam an approximation of loudspeaker acoustics into a pair of ear cups also leads to design compromises needing to be made. Manufacturers like Hifiman, Sennheiser, and DCA do try to tune to their own target curves that they believe sound neutral, and many headphones do feature angled drivers and such to attempt to replicate speaker/ear interaction.