What the hell, I might as well post the comparison I wrote between the K1000s and HD800s here too:
Today, kelvinz came over so we could have a little headphone shootout. We had two beta 22s, a Lavry DA10, and a Buffalo Sabre DAC. Because kelvinz' HD800s have the stock cable, we did most of the comparisons using the quarter inch adapter I have for my K1000s.
Being a music maker, I like to audition equipment with my own mixes. If you're curious to hear the music passages I discuss below, you can download my last album for free at the site linked to in my signature.
My first point of interest was bass performance. The K1000s are notorious for their roll off. I realize that there are amps I could get to improve their extension, but only to a point. They're never going to go as low as the high end Denons do. To test the HD800s, I first listened to a new track I'm working on with a synth bass line built to push my MD5000s as low as they can go. Much to my pleasure, the HD800s gave me all of the sub bass I knew to be there, going as low as the Denons. Its bass didn't have as huge of an impact, but it was noticeably more articulate than that of the MD5000s. It didn't seem to suffer at all from one note bass. Listening to that same sub bass line with the K1000s, I could hear the attack of each note, and then silence. But that attack was even more articulate than what I heard on the HD800s.
Next, I moved on to the second track on my last album. It's a melodic piece made with sampled wine glasses and metal wind chimes. The HD800s handled it marvelously. Throughout the piece there's a warm sounding chime instrument in the center of the mix, pushed back a little bit. Only with the most articulate speakers and headphones does it really feel fully separated from the rest of the mix. The HD800s did so equally as effortlessly as the K1000s. I also really liked how the 800s handled the song's big percussive events. They were clear but deliciously impactful, perhaps thanks to the 800s' ability to present sub bass.
The third track is a gu zheng* based piece with some hybrid synth/acoustic bells thrown in for good measure. Again, the HD800s were equally as able to separate the bells from the gu zheng as the K1000s were. Later in the song there are some high frequency synthetic noises that only very detailed headphones can fully articulate texturally. Both seemed pretty equally able to display them. The K1000s are very noticeably brighter, and thus, might have been slightly more detailed with these digital textures. I'd need more time to say fully.
The fifth track is a much more typical electronic song with a somewhat danceable beat. The last section of the song is a good place to test a system's ability to handle complex passages. The mix is packed with a jumble of percussive instruments that span the frequency spectrum. It was really hard for me to say which headphones handled it better. Every time I though one pair revealed something the other didn't, I found the same detail equally apparent on the other pair. My sense is that the K1000s seemed very slightly faster, but I'd need more listening time to say for sure. That sense might simply be the result of the K1000s' brighter signature. The song does feature a sub bass drum at the start of every measure. Not surprisingly, the HD800s handled that much better.
Like many others have said, I didn't have any "wow" factor when I first put the HD800s on my head. Being used to the horizontally expansive soundstage of the K1000s, the HD800s' seemed small by comparison. But I did find it to be equally cohesive. There was certainly no hole in the middle of the stage. The space between instruments was proportionally a bit smaller, but equally articulate. I didn't have a chance to specifically focus on imaging precision. But I never noticed one pair presenting it more clearly than the other. If I get the chance to compare the two again, I'll give the first track on my album a run though. It has cascading bell scales whose position in the stereo field is particularly tricky to get right.
As mentioned earlier, the K1000s are noticeably brighter. That makes them sound more up front, and more susceptible to sibilance. But I really appreciated that when the recording called for sibilance, the HD800s gave it to me. They sounded warmer too, a bit like how I remember the HD600s. Of course, they don't suffer from the diffuse, inarticulate sound that I hated about the 600s.
Impact, detail retrieval, and imaging precision do improve substantially when I connect my K1000s via XLR instead of a quarter inch jack. I hope that the HD800s make similar gains with a balanced connection. If so, I'll consider them the real deal since comparing them both unbalanced, the HD800s seem to match, or damn near match, the K1000s at their strengths. Given that they also have appropriately balanced bass with outstanding extension, I'm inclined to say that the HD800s are a better all round pair of headphones. For those out there who want a single pair that does everything well, these might be it. For those looking to mix on their headphones, these might be it. I still want to hear how well they articulate small EQ tweaks before I recommend them for such use. But it sure would be nice to monitor textural details and sub bass with one pair.
* a Chinese stringed instrument