Sennheiser HD 660S2 vs Sony WF-1000XM5

The Verdict

These headphones serve fundamentally different audiences and use cases. The Sennheiser HD 660S2 is a wired, open-back audiophile reference monitor designed for studio work, mixing, or critical listening at a desk. Its 300-ohm impedance demands a dedicated amplifier or DAC, making it a commitment to serious audio enthusiasts willing to invest in ancillary gear. The handmade German construction and replaceable components justify the $499 price for that niche. Sony's WF-1000XM5 tackles the opposite end of the spectrum: portable, wireless earbuds with sophisticated active noise cancellation, 8-hour battery life with ANC enabled (24 hours total with case), and support for hi-res audio via LDAC. The integrated Processor V2 and QN2e noise-cancelling processor deliver measurable real-world performance. At $299.99, the Sonys offer considerably more flexibility, offering multipoint Bluetooth pairing, Speak-to-Chat features, and IPX4 water resistance for gym or commute use. The Sennheisers lack portability, require wired connection, and demand equipment investment, while the Sonys sacrifice the soundstage and tonal accuracy of open-back reference monitors for convenience. Choose Sennheiser if you have a dedicated listening space and amplifier; choose Sony if you need wireless versatility and active noise cancellation for daily use.