HD 800 S

The HD 800 S is a measurement tool first and an entertainment product second. The 56mm ring-radiator drivers — Sennheiser's own engineering, not a refinement of the older HD 600 dome — produce a soundstage and imaging precision that's genuinely class-leading. Headphones don't usually do soundstage well; the HD 800 S does.

Tonally it's dry and accurate. Closer to a studio monitor than to the warm-and-musical headphones aimed at the consumer audiophile market. The bass is honest rather than emphasised, the mids are uncoloured, the treble extension is the most extended at any price — sometimes pushed too forward, depending on amp and recording. This isn't a fatigue-friendly headphone for casual listening; it's a reference.

The 300Ω impedance demands proper amplification. A phone won't drive it. A basic DAC won't drive it. You want a proper headphone amp — Topping, Schiit, RME — feeding it from a clean DAC. Treat the chain as part of the headphone, because the HD 800 S will reveal every limitation you put in front of it.

That's the reason to buy it. Most flagship headphones flatter the source. The HD 800 S exposes it. Recordings you thought were excellent turn out to have a noisy bus mix. Streaming bitrates that sounded transparent reveal compression artefacts. It's the headphone you buy when you want your system, not your headphones, to be the limiting factor — and you're prepared to upgrade everything else to deserve it.