Some may recall that I track with Beyer DT-770 Pro cans, because I like the isolation, the heavier bass that lets me hear the kick and bass nice and loud, which makes cutting guitars and keys easier for me. But of course, you really can't check a mix with them, because the bass is exaggerated. So they're quite useful for some things, not so much for others, like most studio tools, right? Before I got my 8816 summing mixer, I used Grado HP1000s. But despite how lovely they sounded, the impedance was way lower than the recommended minimum impedance, and the Neve dealer suggested it would be a better idea to find phones that met the 60 ohm minimum. So about a week ago, I went on a headphone hunt; the minimum requirements were, besides impedance, a flatter frequency response than the Beyers, an accurate midrange, but unlike my old Grados, I decided I wanted good isolation because sometimes I track acoustic stuff in my control room. As luck would have it, I think I found a good answer: Ultrasone 650 Pros. Closed back, so not much leakage; 75 ohms, sounded good in the store. I bought a pair and took them home to give them a whirl. I'm impressed! First impressions: These come in a nice case, with spare earpads, and two sets of cords: one coiled, one straight, each about 3 meters long. The cords are terminated with a TRS at one end, and screw into the headphones, metal-on-metal, so the connection is very strong. Everything feels nice and solid. It's nice to have a spare cord, we all know how stuff gets screwed up in the heat of a session! I may order another spare cord just to have one extra, in case. Comfort is equal to the Beyers, which I like. They fit nicely, aren't too heavy. Sound: Well, they have this S-Logic thing, that I think is basically drivers set up so your pinnae (outer ears) actually participate in the experience of listening. This helps you to naturally locate sound. And let me tell you, when I put on the test CD that comes with the set, and played back the very first track, with a solo clarinet coming out of left field, I was so startled by the realism and feeling that I was hearing something in the room, that I thought I had accidentally left my studio monitors on, and literally yanked the headphones off my head to see where the sound was coming from! But it was coming from the cans. That was amazing. So after a week of breaking them in, what can I tell you about other important aspects? The frequency response is excellent for a set of closed back phones (they also make a nice looking open back model for those who don't like sealed back phones that's also damn nice sounding; it's true that a sealed back phone makes bass reproduction a bit more difficult). The bass is very deep, very solid. Kick drums sound like kick drums and basses sound like basses, not farts or booms. If there's a slight hint of bass tilt, it isn't much, and the midrange is very realistic, and reminds me of the mids on my old Genelec 1031As. High end sounds accurate, not papery. A very good sound. So these are accurate, to my ear, and sound good. The enhanced ability to locate sounds in space means that you can indeed check your mixes with phones (I always do this, for obvious reasons), and listen for potential problems that may not show up on your monitors. Sometimes I work in studios that I'm not as familiar with as mine, so I can take them along to have a familiar reference. Finally, a claimed advantage of this design is that you can use lower levels, still hear clearly, and not endanger your ears during long sessions. I found this to be true. I am listening with them at lower SPLs, and it's working just fine. They're a bit on the expensive side - I've seen them going in the $275-300 range - but even at that price, I think they're a very strong buy. Ultrasone makes a big deal out of the fact that they're a German company, but I noticed they build these in the far east. No matter, the quality of fit and finish, assembly, solidity and sound works fine. Me like.