I might be wrong, but I thought all earphones produced some sibilance by the nature of the sounds in the music, and that excessive sibilance was the problem? Sorry if that is not correct. I too am sensitive to the higher frequencies (the main reason I use EQ) and have rated the phones according to my tastes. With the ZS6 there was a trade-off between reducing sibilance and retaining detail using EQ that I didn't find with the others. Although many would call them 'budget', I wouldn't want to spend $100 on earphones (although I did buy the B&W P5), but I was lucky to find the N1 for $30 in a Nullaudio flash sale the same day I saw them recommended (on reddit), so I was fortunate to get a bargain. Most of my listening (and all of it for recent comparisons) is done on a Lenovo laptop using 250+bps mp3 files via the APO/PEACE equaliser program. Tips used are: ZS6 - triple silicone; N1 - triple silicone; CM5 - stock silicone from ZS3.