Finally got around to modding my 58x… I did the K240 felt mod to the driver and rolled pads to Dekoni Elite Velour and wow I really like what this has done to the sound.
There was never anything wrong with the sound to begin with, but before the mod I thought the sound was a little too similar to my 6xx to justify me actually keeping the 58x in my collection, 9/10 times I would always grab my 6xx over these for listening sessions. Now I actually have a reason to hold onto the 58x and use them more often. The felt mod has effectively increased clarity and detail (especially upper mids and highs) but reduced bass, The Dekoni pads add more bass which cancel out the reduction from the felt mod (just slightly more bass than stock now) and cuts down the treble a tad. Plus they are infinitely more comfortable now.
Might try the furniture pad driver mod next instead of k240 felt to see how it does, also thinking about some dekoni hybrids next time they come around on massdrop or maybe Yaxi pads…