I've modded another pair of pads, without the annoying velour this time. Yes, velour doesn't improve the sound and makes them "scruffy".Decided to keep the foam damper. Still has pad vents, but in large holes, not a pattern. This, along with the foam, keeps the pads stiffer and higher.Trimmed the mounting tape to not cover the holes in the back of the plastic.No venting yet, as they're real close to neutral sound. I'll try with smaller amount of venting.8k "blip", surrounding wiggles and 14k dip are definitely caused by the back metal grille. Removing it removes this issue, but I'll need something quite transparent to dustproof.Likewise the front dust cover is not transparent, eats 2 dB of mids and highs, starting with 1kHz.--Yep, small back bottom vent (2 strips of electric isolation tape per channel, 4 times each) improved this without introducing a 4k peak and a huge 2k dip.
It seems that removing the foam circles from the pads causes the 4k peak and 2k dip. Maybe your original pads didn't have that?The back vents generally lift treble up or reduce bass - full ones as described in the mod, by ~4 dB - 1.5 mm thick - makes them way too bright if the dust cover is removed, but correct with the dust cover. These tiny slit ones lift only by 1.5 dB. The slit is 0.4mm thick and narrower due to the use of only 2 layered pieces of tape per channel.Removing the dust cover increases treble above 7k like a 2 dB/oct parametric equalizer, except it doesn't boost the 10k part. Vents work slightly lower, above 5k, so the sound is a bit different.Cutting large holes (or many small ones) in the back of the pads smooths out 6k dip and reduces bass resonance - cupped feeling to the sound - but you already know that.Removing back grille (and dust cover) removes small wiggles in the 5-9k range as well as the huge 8k dip. Reduces the 14.5k dip as well. Makes the sound yet more open.Just trying it is trivial - use a flat screwdriver to remove the holding rings, then remove the grille. Easy to replace.Velour top mod causes a large midrange (500 Hz-1.5k) dip with a minor subbass drop. Also velour is nasty and abrasive. Adhesion mod never worked right for me, unglued after a time - I'll try again with a stronger adhesive.Now I'm trying to figure out a way to protect the headphone against the dust without damaging the sonic qualities, as well as a way to remove the remaining 14k dip (~3 dB) and the slight 1k-2k dip.In general, very similar to Jergpad 1+2, with different hole structure (large holes in the middle instead of more slightly smaller ones), smaller slits and no frontal dust cover. Jergpad 1+2 still had some remaining highest end cut. I didn't attach them with tape just yet, only the pads to the mounting rings. I've also attached the pad to the mounting ring with some extra tape at the "large slits" parts without covering any - so that the pad never falls off the ring.