All art, instructions, material selections and information in this post and following posts (collectively the "SuperBAF HD800 Community mods") are covered by the Creative Commons Attribution-Sharealike 4.0 international license. Any derivative work may be sold as long as instructions and art are distributed freely and correct attribution (mention of the name of the mods, SuperBAF, and a link to this thread) is maintained. So I got my HD800 back yesterday with the SBAF mod outlined here. As is, it is an excellent improvement over the current swath of mods and I find myself able to listen to the HD800 with ease. It is very much comparable to the Anax 3.0 mod, and I find the new organic material that @zerodeefex picked out to be better at doing its job. I do plan on attempting to add/change a few areas based on what I've played with in the past and what others (who have not published their mods) have suggested. This will be a more methodical approach (both by measurement and by ear) to headphone modifications that seeks to isolate each specific tweak and quantify its effect, and ultimately find a combination that gives the best result. I expect this will be an ongoing process. Coming from dead stock let's list and review all the things we can change: --- Dust cover: Take it out. It sounds worse --- Absorber: We first saw people using the shelf liner in the Anax 2.0 mod in an attempt to cure the extra reflections that would be bouncing around the silver screen that makes up the HD800's large enclosure. The silver screen is necessary to maintain our bass response, but it creates the diffuse treble effect. At this point, the thicker absorber shown in the SBAF mod v1 is an excellent choice. Its effect is seen as reducing the 1k-4k depression which makes this overall sound more even. It does not, however, do much to counter the 6k peak, although it might play a part in reducing treble energy above that region. --- Resonator: This refers to any sort of tubing you might choose to place inside center of the HD800's driver. As of now, there is the z28 Resonator and Dupont Resonator that aim replicate the same HD800S design trait. As we learn more about what the HD800S is actually doing, we can try different materials and geometries in this position. The resonator mod directly effects the 6k peak and might be our strongest tool to combat it --- Ring: This refers to the metal ring that sits around the HD800 driver. The original HD800 mods aimed to place damping material here. Now that we (presumably) have a larger "absorber" that overlaps the metal ring region, any additional damping on the ring might have questionable effect. I will attempt to unravel if there needs to be a material here --- Trapezoid: This refers to the black plastic region that lies over what is the connector housing inside the cup. The question here is similar to the ring one in that now we have an absorber covering it, it is of questionable effect.