Actually I have both (I just got the Szalayi very recently while owning and loving the Mk2/Reborn for many years). My first impression comparing these two is: If you are a fan of the Oriolus house sound, then they complement eachother very well. I would describe both of them as full, very wide and euphoric sounding, they
clearly share the same DNA. With both, focus is more on conveying emotions than on analysing the music in every little detail (though they are no sloughes in the detail department either). Bass with both of them has slower decay and gives you that really rumbly and quite physical feeling, while it seems very well separated from the rest, almost as if bass instruments are further away (I find that effect quite special and know only a few earphones that do it in a similar way).
Just the Szalayi has an even more elevated bass, it`s actually quite mighty (but not overdone!). That changes the tonal balance and perception of mids and treble a bit. Mk2 is obviously more centered arround mids/vocals, while Szalayi seems to extend a bit further to both ends and keeps the vocals in line. In other words, Mk2 shines especially with vocal based tracks while Szalayi is perfect for electronic music. I am super happy that I own both now!
(Just I don`t like the look of the Szalayi...looks terribly like a toy from a bubble gum vending machine...imo.
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