Agreed. I don't have the TH-600 anymore but they have excellent air and transparency. It is one of my favorite closed headphones but the mids can't touch the AD. I would say my own modded T50RP with the vents only slightly blocked sound more "open" than the AD. However, the AD is a step up above my own modded version which is darker in tonality. The AD's treble is clean and the bass tighter than my own mod. Imaging is on point with this AD. To my ears, the TH-600 is euphoric with it's U-shaped frequency response and the AD's neutrality makes the experience honest yet lively esp. with a good tube amp. Will eventually getting around to trying the AD on a SS amp. I could see there might be times I would prefer one headphone (AD, TH-600) over the other but money no object I might have both in the arsenal because their attributes complement each other. With the Decware Taboo which tends to be a transparent amp there is no congestion that I can hear in the AD. The AD doesn't scream treble energy which at times I may even mistake for transparency and air. I don't have the LCD-2 anymore but I recall that planar as not having a huge soundstage even though it was an open headphone. Like the LCD-2, the AD is an intimate experience and like many have mentioned we don't necessarily need to go super wide or deep in the acoustic presentation. AD seems just right for my listening habits (jazz trios). After a week with these ADs I am a happy planar camper.
Zowki, that's what I thought too. The AD sounds fantastic, one of my favorite hp's in fact, but it doesn't sound open to me. However, I heard no congestion, which is a problem for many closed cans. The only "closed" phones I've heard that sound open are the TH600/900. But they don't isolate as well as the AD, and I agree with above that they'll never be HD800 open, but then neither is any other hp.
Edited by WNBC - 10/17/13 at 7:07am