[gammi]

Just picked up some in ear microphones (MS-TFB-2-PREM) and did frequency sweeps on almost all of my headphones.
Note: This mic has a treble dip at 8K, so ignore that for all readings. Upper treble gets messy on these sweeps anyway.

Some thoughts:
-Susvara and CA-1a both have odd resonances that create a sawtooth effect. Probably why people love Mitch's filters so much on the CA-1a, they correct this. CA-1a had the open pads on btw.
-Inversely, X9000, Expanse, Nova Signature, Verite Open and Utopia are all exceptionally smooth in the sense the curves are the least jagged.
-But Verite Open has some seriously large treble dips at 1.2k and 3k.
-SR-007 MK1 and LCD-R have smooth readings too except for some weirdness going on in deep bass.
-SR-007 MK1 is known to be warm, and it is, but because of treble dips at 1.2k and 3k not because of more bass. It actually has the least amount of sub-bass of them all. Mid-bass has a little hump.
-Nova Signature looks like a better SR-007 MK1 imo. Less bass roll off and less treble roll off. Makes sense, since to my ears it sounds both warm and detailed somehow. It's like having the SR-007 warmth but also treble detail, win-win. Probably want to tame that spike at 1.7k though.
-Expanse has the most bass and a very smooth treble roll off without any spikes, it's no wonder I find this to be the easiest to listen to and is a favorite of mine when I want music to be smooth/unobtrusive like when I'm working. Anyone sensitive to treble probably loves Expanse.
-X9000, Nova Signature, Verite Open, and LCD-R all have exceptionally flat midranges from 100 to 1k or so.
-SR-007 is pretty flat too except for the dip at 500Hz and it rises earlier than the other STAXs, rising from 500 to 900.
-Sizable spike at 6k on X9000 is worth experimenting with bringing it down.
-Utopia spike at 5k isn't bad when you look at it on its own but probably sounds sharp because 500-600Hz is so recessed.

Hope this helps some people, let me know if anything else stands out to you.

 

[AnakChan]

Interesting, I only had a few mins with the SR-X9000 but didn't hear the 6k peak. Got to try to get another chance to listen to it again.

 

[SolarCetacean]

Interesting, I only had a few mins with the SR-X9000 but didn't hear the 6k peak. Got to try to get another chance to listen to it again.

For me, the 6K peak isn't as large as the measurement says and is flanked by small dips, so the peak isn't that noticeable in music, it mainly contributes some bite and incisiveness to the sound. I only found it via sine sweeps.

 

[gammi]

Interesting, I only had a few mins with the SR-X9000 but didn't hear the 6k peak. Got to try to get another chance to listen to it again.

I just did a sine sweep and yeah, I hear it get a bit sharp around there. Only place in the sweep it hurts a little. Maybe also slightly at 10k-ish.
Also agree with Solar's point that it's flanked by a small dip, 5k and 7k sounded like they dipped a bit. 3k too. Overall when it does deviate from flat it seems to deviate in a way that it undershoots and then overshoots, thus oscillating around flat and seeming flatter than if there were just a null or spike.

Despite the sweep getting sharp at 6k, I've never found it sibilant when listening to music. 6k is presence/overtones/sizzle not really the actual fundamental frequencies of instruments so I think a spike there is going to be a lot more benign than spikes lower.

Also worth noting I could hear the bass start as low as 22Hz. Ear drum vibrating kind of deep bass down there. I respectfully disagree with the estats can't do bass crowd.