MASTER INDEX OF CSD / WATERFALL PLOTS THIS IS OUT OF DATE - I AM NO LONGER MAINTAINING THE INDEX (THE INDEX IS INCOMPLETE.) YOU WILL HAVE TO SEARCH THE THREAD OR GOOGLE. I WILL OCCASIONALLY POST SOMETHING IF THERE ARE REQUESTS OR PEOPLE SEND STUFF TO ME. Audio Technica AD2000 Dr Dre Beats Studio Coby Darth Beyer v3 Denon D7000 Koss DJ100 Koss ESP950 Fischer FA003 Sennheiser HD25 Sennheiser HD558 Sennheiser HD650 Sennheiser HD800-mod Grado HF2 Joe Grado HP1000 AKG K240EP AKG K270 AKG K340 AKG K601 Audeze LCD2r1 Audeze LCD3 Symphones/Grado Magnum Audio Technica M50 V-Moda M80 PERFECTION loopback Sony SA5000 STAX SR009 Grado SR80i-mod-cup Grado SR225 hure SRH840 Grado RS1 Beyerdynamic T1 Fostex T20RP Fostex T50RP-mod Sony XB700 --- ORIGINAL POST STARTS HERE I'm been meaning to do this for while now, but finally got off my ass and unpacked my measuring gear from storage. CSD plots tell us a bit more than FR graphs. Both are great visualization tools to help us find problems (at least that's what I use them for when I build speakers, not to self-pleasure myself that my headphones are amazingly completely flat from X to Y Hz.) Just a word of caution. Take these with a grain of salt. I did not perform these measurements in a laboratory quality environment, an anechoic chamber, or precisely controlled conditions. It is a serious pain-in-the ass while taking these kind of measurements to minimize reflections and artifacts. Anyone who is interested can PM me if they have any technical questions as to how I set things up. I would also advise against comparing these CSD graphs to other CSD graphs (I even feel uncomfortable comparing graphs from different measuring sessions!) There will be differences in environmental conditions, measuring methodology, and how the graphs are visualized. For example, the well-known LCD2r1 CSD graph gets cut off at -25db. These graphs go down to -50db - probably a little more than necessary - but I just wanted to see it. One of the reasons I performed these measurements was because I wanted to objectively see the effect of the "Jazz mod" on the HD800s. I used two layers of adhesive lined felt instead velvet for my HD800. I only covered the metal and plastic surfaces and did not cover the grill on my HD800s. HD800 (SN# ~10000) CSD: You can see that big ridge around the 5.5kHz area that many of us are aware of. That tiny ridge at 3kHz is looks like an artifact and is probably not audible. HD800 CSD with variation of "JaZZ Mod": It's hard to see because the wide range of the Y-axis on the graph, but this mod does tone down the treble region. It also does some funky stuff at the tail-end of the "problem" area. It shifts it lower in frequency a bit, broadens the peak, and kills that last tiny bit of resonance after 2ms. Probably a very slight beneficial result overall on that specific area. HF-2 CSD: Just for kicks.