Ok guys here's some FR+HD graphs of both the pre-production 560 and production 560, and a CSD of the production 560.
Production 560 FR+HD:
Production 560 CSD:
Preorder 560 FR+HD:
I know these can be hard to read, so a couple of things to note:
-Treble rolloff after 10khz is most likely a measurement artifact
-Both models seem to have pretty much the same frequency response, with the preorder maybe having slightly less of a hump centered at 4khz. Different iterations of each measurement will produce slightly different results because of the nature of measurements themselves
-These headphones have overall some of the lowest distortion numbers I've seen on any of the headphones Purrin has measured. Second harmonics are usually benign compared to 3rd and 4th order harmonics unless there's massive problems. The 560 manages to stay pretty much under -90db in these areas, whereas other headphones like the LCD-X and HE-500 are just under -80db.
-The 560 boasts the typical linearity from bass to 1khz as with all other hifiman planars, has a null at 2khz, and is back to near neutral in its treble presentation. Upper treble is much more in control than any previous Hifiman yet.
-CSD shows a really clean decay, with the 4khz resonance possibly being traces of an 'ortho wal,' which is usually seen as benign compared to other resonances.
-These have somewhat of an Audeze look to their FR graphs, with a 10db shelf from 2khz and beyond, but sound nothing like an Audeze. They sound much less dark and congested compared to an Audeze. Just goes to show you that measurements aren't everything.
Take a look at Jerg's topic
here for comparisons to HE-500 measurements. Take a look
here to compare to HE-4 FR+HD.
Purrin really likes these, and commented that they are worth it over an HE-500 for "comfort and fit, bass clarity, being less bright than HE-500 in the upper treble, and being more resolving." He also didn't like the HE-4 too much for being 'thin and having a tiring treble." He also refers to the HE-560 as an "Abyss Lite."
A couple of my own remarks..
I initially thought the 560 had a peak or a resonance in the lower treble around 6khz, but it turns out it was the peak at 4khz. This is far less harmful than a peak in the upper treble anywhere around 8-12khz. It adds some presence to stringed instruments and some snap to percussion, as well as some other things, "F" sibilances will be a little emphasized compared to the usual "S" and "SH" sibilances that you would hear on other headphones.
I never heard a null at 2khz, and this will most likely be benign for other people. For what it's worth, the null at 2khz is probably why I like this headphone quite a lot. Through my experiences I've found that too much 2khz can make a headphone sound plasticy and fake, while a slight reduction of it gives the instruments a much more "live and warm" sound.
Overall I would categorize this headphone as near neutral with slight warmth.
