Philips named this series after Beethoven's only opera Fidelio, which shows its high-end positioning. Fidelio X1 is a high-quality product that can really represent the standard of Philips flagship HiFi earphones, with luxurious materials, breathable velvet ear pads, and calf leather headband. The low frequency is warm and full, the voice is full of emotion, the high frequency is extended in place, the sound field is broad and profound, and the positioning is accurate. Meiya