In the hd600 there isn't any peak, they are one of the flattest pair ever made. The hd600 doesn't have any big flaw, their sound is dedicated to mid lovers like me, the stage is just perfect to an intimate listen, the bass is tight and musical but not distracting from the voices. their rhythm is engaging and I can feel an ethereal image floating all around me with an unrivaled sense of presence. The dynamic and the transients are astounding: the wow factor is there. listening to Jonas Kaufmann Verdi Album (one of the best classical voice recording) is a private concert: from the first time the gentle notes are really gentle, and the full volume of his voice has the harmonic complexity of my live experience in front of him; Haken - Virus is presented as intended, a well distinct wall of sound. there are Not reverberations, no fake details, no overdone frequencies. You can't call flaws these wonderful features.
Maybe some find THE masterpiece a little boring, but not me. Music at his intended state is not boring, it's true. HD560s (from oluv's demo comparison against THE queen of flatness) adds fake details and a bigger stage making them more engaging at first. Wow factor reached for a day. Other manufacturer did the same operation in the past: Philips with the shp9500, Audio Technica with a lot of models (while the r70x, being a pro oriented model, seems to have more hd6x0 resemblance), Beyerdynamic with all the dt serie, Sony adding bass until it's too much. I have a good hearing from 20 to 18,500 hz, so I can easily hear lifts from 1,5 db in all frequencies from the standard (hd600).
Oluv measurement and test are pretty accurate. The difference in the mid treble zone, due to the angled drivers, is gigantic for my tastes. The perceived graininess sometimes comes from the lumpiness of that precise region. Yes, you can call it detail.
The extended bass lessen the perceived kick of upper bass and the body of a Baritone voice.
The width of the stage isn't related to the most important aspect of the image (for me): the depth. I prefer to perceive more layers than a super wide image.
But It's me. As a lover of mid to hi-fi I'd prefer to see a more controlled hype. The hd560, like the hd650 and the 58x before, were created to give to the consumers what they wanted, but Sennheiser knows very well that in few days the 560 will be clearly in the 100-140 street price league, just under the x2hr and the dt880, as a non professional, music lover customer oriented because, as Beyerdynamic very well knows, the 4 to 7 khz must be flat or recessed to compensate the concha gain, and the brilliancy for the highs enthusiasts (or old eared people) must be positioned from 8 khz to the end of the hearable. This must be clear to 5 khz sensitive guys who are searching more sparkle/stage/bass than their hd600. There is a model who can do this a lot better than the 560: the AKG K712 pro, ah hidden masterpiece dedicated to hi-fi enthusiasts who love a spicier reproduction. I desperately am in search of good a pair, but it seems that the Slovakian factory has a bad quality control. I ordered them three times and every pair had a hair behind the membrane (!!!) creating an unbearable vibration in the lows. Other well done flat closed pair? the AKG K371, Shure SRH940, Beyerdynamic DT250 250 OHM. The first has weak screws on the headband, the second is made of the worst plastic in the world, the third has seal issue on the left cup that create a severe L/R unbalance. So the entry level market of open cans has a hole in it, and the hd6xx have their negative aspects (price in Europe).
