What is it?
Ollo Audio made serious waves with its initial S4 headphones, taking on existing players such as Sennheiser, Audeze, Beyerdynamic and Slate Audio. It also developed designs in closed-back (S4R), open-back (S4M) and immersive mixing versions (S5X). But now it’s all change, as both the S4 and S5 open-back designs have been replaced by the new open-back X1.
