250 ohms. It's the middle of the road in terms of resistance. So how do the 701's stack up? These are brand new Q701's. Like they were in the package 5 minutes ago. I'm listening to a hard rock song on an E9/E7 combo, and I have the volume on the E9 at just over 1/4 way and it's just under loud enough to start making me wince. I routinely listen to the DT880 at 1/2 to 5/8 volume to get the same level of sound. So there you have it. The Q701's are about 1/3 louder at the same volume setting than a 250 ohm headphone. I imagine my X-fi with no headphone amp could drive these to painful levels while on the 880 it was just barely 'enough'. While I'm on it, my initial, 10 minutes of listening to Q701. The only really good phones I have to compare with are the 880's. The first thing I notice immediately is these are colored. They color the mid range and the highs a lot. The 880's are pretty neutral and transparent but this is very different. I wasn't expecting it. I know that I have about a week of solid burn in ahead before they start to open up, but out of the box they aren't harsh or hard to listen to, so much as feeling like somebody's been touching my equalizer settings. Beautiful headphones though. Very well built, about as comfortable as the Beyerdynamics except for the headband, which isn't quite as comfortable on the top of my head. The Beyer's are squishy and soft, these are leather and stiffer. I expect that to relax once I break them in a little though. Two cables, one long, one very long. Can't complain, it's about the same thickness as the Beyerdynamic one but a little more plyable,perhaps because it's new plastic and hasn't started to age yet. I have a whole night of listening tests ahead. I'll check back in later with more observations. Edit 1 An hour later and I have the 880's in the 3.5mm and the 701's in the 6.5 which is supposed to be -6db compared to the smaller connector and the 701's are still louder. But having both headphones powered at the same time allows me to do a quick change, mid song and see the differences. In even an hour, the sound profile of the 701's have changed. I've never experienced this with headphones before, to have the sound change so much in an hour of break in. Some of the resonances and coloration have relaxed and they are starting to open just slightly. I'm listening to Gordon Lightfoots "If I could read your mind" and swapping back and forth. The mid range on the 701's is quite pronounced still but not as harsh as I first judged it. The 880's by comparison are black, no grain at all and silky smooth but detailed. Then again they have had 2 or 3 years of daily heavy use to open up. I don't notice much difference in soundstage yet on the 701's or much difference between their 'open' and the 880's 'semi open'.