EDIT: Marv's measurements start here: http://www.superbestaudiofriends.or...mpressions-and-measurements.5338/#post-178987 Zach was kind enough to lend me an Auteur for early impressions and measurements. He said this is the production tuning. They also sound pretty good! He sent them to me with two sets of pads, the Eikon perforated pads and the regular Auteur pads, also perforated. The Auteur pads have a larger opening, but otherwise they are fairly similar. Here's how they sound with each set of pads. Auteur pads: - Really, really nice low end. Cleaner, better defined bass than the HD600/650. Less mid-bass bloat, more emphasis on lower octaves. Great extension. Very powerful sounding but well integrated. - Very smooth, gradual transition into the midrange. Midrange as a whole is close to rivaling that of the HD650. - Treble area is brighter and rougher than the HD650, but still sounds pretty good. Not what I'd call bright or fatiguing. - Staging may or may not be a little more forward and less open sounding than the HD650, but they do have a nice 3D sense to them (i.e. stuff sounding like it's in front of you). Maybe a little more like the open Focal headphones in their presentation than the HD650. - Nice sense of detail and resolution. Sounds snappy and crisp. Low level details seem to come through. Relatively clear sounding. I haven't really been able to ascertain their speed, ultimate resolving ability, or any sense of dynamic compression, but they're at least on par with the Eikon and Atticus, if not better. - Really engaging sound overall. (Spoiler alert: I prefer these pads, but if I owned an Auteur, I would use these pads with a wee bit of additional front damping to smooth the treble a bit more.) Eikon pads: - Similar bass and midrange as the above. A little more forward sounding, so not quite as clear sounding. - Overall darker tone. Treble sounds really good on these pads. - Staging is a little more forward. Even more so like the Elear or Utopia than the Auteur pads. - But there's something that trips me up. There's this sort of midrange aggressiveness with these pads that really bothers me. Fans of the HD600 might like this. - Otherwise, there are no earth shattering differences between the pads. Overall, I think this is a little more what people were looking for in the Elear. That, and the headphones are gorgeous. Zach did a really great job with these! These very quickly became one of my favorites.