Disclaimer: Very preliminary and exploratory work. Needs a grasp of salt. Value statements or over-interpretation never recommended.
Now I started to measure this thing – one of the reasons why I wanted to own.
Those who are not familiar with measurements of this kind of FULL LEAKING headphones must first read discussions and questions raised in the days of AKG K1000. Technically this is not a cirumaural headphone (aka overear headphone), therefore acoustic theories based on AE/OE are limited to unknown extent.
That said, results indicate several interesting points – to me.
I previously posted about placement and positioning. And the result above confirms possible variance.
Below is Tyll’s measurement of AKG K-1000. It also has positional response variance. But to less extent.
Note that Tyll’s are uncompensated against head and ear gain. Relative difference is still meaningful though.
With a single channel driven and and my wing placement (ears barely touched to metal frame), frequency response looks like the following:
To understand my compensation better, new-pad HD600 (sounds brighter and more aggressive than well-worn) added to the graph.
2k peak is partly explained (if not entirely) by possibly DIFFERENT interaction with earcanal and ear drum gains of head-related overall gain (aka HRTF): see below.
AKG K-1000 with independent of direction compensation had that peak. Very interesting.
Bass response is so FANTASTIC that can impress me for such a full-leaking structure. Note that bass is not (and should not be) compensated against head/ear gains. So, this region is easier to interpret without concerning with HRTF.
Response starts to drop from about 50 hz (small and mild peak at 90hz is due to reflection). Drivers without enclosure seem to have this character – drop slightly before its resonance frequency. Note that MySphere 3 has resonance at 55 ohm and K1000 at 70 ohm.
I also took near-field pink noise RTA with measuring mic, which was the same as I got with EARS in the bass.
Above is a near-field UNCOMPENSATED response of MySphere 3 (I don’t attach their compensated one because they adjusted bass, which I never agree with).
So, measurably SR1a has deeper sub bass extension than similarly structured headphones (K1000, MySphere 3). Actually it could be rivaled by only a few open-back headphones. Note that Utopia has leaner response, although it is an engineering decision associated with smaller (40mm) driver size and excursion limit.
Finally below is the waterfall plot (plotted from 0 to 5 ms).
As expected (no cup reflection and reverberation), cleaner than any other traditional headphones to date. Of course, be careful that cleanness may not be associated with higher quality.
I will have more fun with EARS and SR1a for sure… and report it back here.
PS. Measurements taken at 92db at 300hz. Slightly lower than my usual work, but I was concerned with power handling limit.
), of course without having heard any part of the chain yet at all. So I‘m in for an interesting journey as well, with no idea what I will ultimately end up with. For me, that ride is part of the joy, isn‘t it 
).