Just received my pair today, and straight out of the box they very clearly have the same problem in the right ear cup and/or driver that I hear lots of others complaining about. Crinking sound when I move and a 90% drop out in sound when I turn my head to the right? Bizarre. Sad....the weight still feels like I've strapped 2 bricks to my head.
This has been discussed numerous times, ever since HiFiMan and Audeze restarted the Planar Headphone Age.
Every single planar driver exhibits this issue, but the degree to how much this is perceivable is different per headphone and per person.
The issue is to do with seal and air pressure between your ears and the planar driver, and is exacerbated with closed back designs predominantly.
Essentially, if the seal is too good, especially on both EL-8 CB (2015 or 2016 models) and EL-8 Titanium, and you lightly touch the earcups, or move your head more than moderately, then you will hear this 'crinkling' sound.
Even
Z Reviews mentions this, and he had the Audeze El-8 open back (very likely the 2016 model).
On the EL-8 series, if you don't seal too much (allow some external air to pass between the pads and your head), the crinkling noise should dissipate.
However, in rare cases (from the 2016 versions), if the crinkling occurs with extremely minor movement, or with a poor seal you still hear this noise, contact Audeze customer services immediately.
Here's the video of the Z Reviews review of Audeze EL-8 (I think the 2016 model); watch from around the 6 mins mark and the reviewer will mention the crinkling noise, or as he describes it,
"crunch crunch":
