Getting tired of cables I decided to convert some of my cans to 3.5 jack since I already have good (sibilant free) cables. All other gear never showed even a glimpse of sibilance, also I tried to choose no sibilant hp's for my collection.
Disassembling Takstar Hi2050 I decided to rip both inner filling and outside sponge and thick and dense felt cover covering all speaker grill. Since I have an experience with “unveiling” sound signatures, I replaced huge inner insertion by a piece of medium dense smooth felt.
Trying on I found a positive change in soundstage, all became sharper. Much brighter, but not harsh. Not a solution for treble haters, but many songs now sound very open and airy. Getting free space inside cans also added a bit of body to lows and slightly improved the punch.
All mentioned changes for me were pure positives, but listening for some of test tracks I found a horrible sibilance in voices and instrumental part.
Returning original felt cover removed sibilance, but also returned a correct but dull and lazy sound.
My wife found in her collection another piece of wool felt. Twice thinner and with lower density. Much lower I should say. Trying cans again I found sound more cleaner, sharper and airy. Problematic tracks now sound “clinical”, but no sibilance, or better say on the edge of being sibilant.
Since putting denser and thicker cover will kill the vibrant sound again, at the moment I decided to keep them as-is till I’ll find some other materials to try.
Sibilance is under control now, but treble is clinical, not for lazy-dazy music hearing.
So I'd love to soften them a bit for everyday use, but right now they truly deserve the name of the studio/monitor/reference cans.
Also I’ll give 3 tracks which became heavily sibilant (the first one was a 100% surprise for me).
1. Bananarama – Venus
2. Edith Piaf – Padam… Padam
3. Emerson. Lake & Palmer - Fanfare For The Common Man
Some time ago I was looking for sibilant tracks in other places and found that many persons mentioned that guitars in Nirvana’s – "Smells like teen spirit" are sibilant. But even stripped Hi2050 showed me nothing in this song.