Pics and or list of other mods, please.
Thin Creatology foam works better. As few gaps as possible. As exact as possible. Using tissue paper and markering it out and glueing it on foam to cut it out works for certain parts. Pads massaged, wrung between fingers to better conform to ear. Foam insert too. Seems to increase linearity and extension. Wear gloves to avoid massaging in hand oil. Sharp scissors. I lined all the black plastic and the silver damping mesh. Foam is softened a bit by crumpling and crumpling, to make it pliable. That should make it a little more porous. Felt/cloth caused a 5k spike, damping everything except the worst resonance. I scrubbed the backside of the earpad with a stainless steel brush, for better diffusion of sound. Applicable to all parts except where the sound is travelling directly out of the driver. Polish with a microfiber cloth, etc, fine, reflective wax/surfactant. I pushed the back damping foam so it curved and exposed the magnet a bit. There is still damping to restrict the air, but the reelection from the foam happens later, so treble is a bit more linear and extended, at expense of worse slightly worse decay, but better FR and impulse.
When I added foam or microfiber and didn't cover hard surface, simply taking up space and obstructing diffusion and causing earlier refelctions---I caused earlier reflections. Resonance at couple certain frequencies. It is higher resolution--as per faster decay every where else. But FR sucks real bad. I tried free foam, less dense, and that helped decay, but hurt FR by roll off at both ends.
This of course, is tentative, what ever works for you.
Covering the plastic surfaces of the inside of the grill seems to work, but I need to test that again. I tried puncturing and abrading the surface of the foam to increase surface area, but I need a way for it to be controlled and repeatable. I used a screwdriver and steel brush. The steel mesh itself is removable, if you push right close to the edge, and you can fit foam/putty in the crevice, before/after you glue it back. Stock glue is like hot glue-ish. Thickish viscous drops.
I brushed the steel surface on the inside. I put some foam in those cylindical holes on the grill cover and in the headphone backside.
Putting foam in the front of the headphone, where the plastic is--that's tentative still. I tried it a couple times, but I want to focus on backwave damping first, where the cavity volume is far bigger so I will induce less resonance by obstructing the sound waves.
I did brush it. I covered the driver opening with tape first, to protect it. If you make the back side of the headphone fairly hermetic, as with the foam, you rish crumpling the membrane from the suction when removing it. It's mildy harmful, but I didn't notice any terrible effects. Still sounds similar. Might sound different. But burn in and the other mods and mod removal make it hard to strongly causate.
I tried putting foam underneath and inside the lower part of the grayish headphone bolster thing. It helps high treble but is probably a tertiary thing for you to try. Also lining the mesh on the front of the headhpone, making sure not to obstruct the driver that is covered by the mesh. So theres the area of the driver opening and then there is actually twice the radius of membrane surface behind the mesh, obscured. Weird--in that it contradicts our popular notion "don't obstruct the driver". Senn apparently needs it. Bass propagation surface.
So, principles:
1. cover hard surfaces with more compliant material to absorb spurious waves that reflect and add non-signal noise to the dri
ver. You need hard surfaces. Bass. But you need some reservoir to absorb extra energy that doesn't float into free space. And even a free space driver--you've heard them (take out the driver and hear it in free space, though your own risk cause the wires are stupid (not really stupid though) small) have little bass and mids sound smothered. Kinda like that popular Koss. Linearish. But decay still sucks.
2. make no irreversible mods
3. keep cavity volume as high as possible
4. make most hard surfaces irregular to scatter sound
5. mod one side first to experiment and compare with stock
6. do both sides at the same time, to ensure the same sonic result in both sides
7. felt, cloth, more porous foam kills bass, harder less compliant is conducive to bass
8. "bass" "mids" "treble" are not necessarily exclusive. Bass notes pop in with treble and have timbre in mids. Linearizing and helping the decay of the latter can help you hear the former. Treble notes can start in mids and evolve all the way up. Cymbals are kinda like white noise and need linearity to sound full and good decay/attack to not sound like noise or mush. And mids by god, are each individual instrument's tones across the spectrum, and would really like you to have everything in FR
9. check with sine sweeps and a variety of songs. I use retro video game songs because of their simplified, synthetic timbre and soundstage allows to more easily pick out sounds and also treble peaks/broad humps (megaman wily stage, Katamari Damacy etc). Youngblood brass band for precussion and timbre and soundstage complexity and instrument placement. Depth. Decay. I used to use daft punk, too. But it was kinda annoying in the repetition and musical structure--but early on that repetition was what I need to pinpoint sonic characteristics. Then the good stuff, well mastered stuff. But only after it passes the previous tests.
10. tonality and technicality together will sound sweet and full and impactful and you won't need to strain to hear every instrument. You'll just hear it. On the way to getting there, I felt the mids popped out, but the treble was in the background--mids spike. Or the mids and treble both popped out but the bass was lacking--mid and treble broad hump. Or that the bass was really strong and mids were full but I got a headache--bass bump w/o extension and lower distortion. Or that it was airy but not really--non linear treble, a dip in the middle. Or that everything sounded so alive but lacked full body--last couple octaves of treble linear but high mids spiked or sucked out.
11. tools were shozaburo white steel scissors, which are high-quality fabric shears, and husky precision screwdriver set to place the foam, when fingers get glue and refuse to release. Used 3m ones and couldn't cut to the size I needed.
12. you'll make a mess and smell of plastic and organic compounds and tarish stuff, so take the audio headaches, time, frustration, and exclusion from the rest of you life accordingly
13. done well, you'll eventually realize what Anax says when he values technicalities and micro-resolution more than FR. And it'll jive with what you've done trying different tonalities to get the info better revealed by technicalities. Presence of an instrument is being able to hear finer and greater range of delineations in pitch and dynamics.
14. small little sub milimeter pieces of foam and covering matter. I hope you'll be able to be able to hear their differences in helping the acoustics.
15. dynamics, when damped better and better, lose grain and reveal resolution deeper than planar or stat. Planar and stat have a choral effect with sounds. Its a matter of number of singers, more # with stat.
16. when you smile listening to music, when it gives you no earaches, when you can take off the headphones and not feel real life audio now sounds off or weird, when you can turn it up, when each recording has totally different
soundstages and mastering and you can hear it, when headphones allow you to get by with 2-3 hours less sleep a night because the music is good enough to calm you down that much, you're done. I'm not there yet. Tried, got there with another headphone (a planar), messed it up, and now I'm at a platform with greater potential and far better comfort.
17. softer earpads and headpad better fit it to the head. comfort and sound increase.
