Castle Windsor Series loudspeakers are born and bred in Britain

Castle Windsor Series loudspeakers are born and bred in Britain
(Image credit: Castle)

This is British Hi-Fi Week on What Hi-Fi?, and what better way to kick off than with some new loudspeakers that are designed, developed and manufactured right here in Blighty?

The Castle Windsor Series is a new range of loudspeakers that comprises the Duke and Earl models. They're the first Castle speakers for many years to be UK-made – taking advantage of parent company IAG's new 9000 square foot production facility in Huntingdon – with every critical part developed and manufactured in-house. But that doesn't mean they've cut any corners.

In fact, they're designed by world-renowned speaker designer Karl-Heinz Fink and his Fink Audio team. Yes, the same Karl-Heinz Fink who we awarded the Outstanding Contribution Award at the What Hi-Fi? Awards 2022, and who we called "today's most influential speaker designer".

The Windsor Earl is slightly smaller than the Windsor Duke, but both feature very similar insides, including mid/bass cones made from a polypropylene-based material. This is precision-cut into strips, woven and then bonded together to form a solid foil, which is then pressed into shape and cut to size, producing a material with different properties of rigidity at different directions between the voice coil and the surround. This helps minimise resonances, creating a flatter response curve.

The cones' surrounds are made from low-hysteresis rubber which won't deteriorate over time, while the voice coils are made from glass fibre bonded with high-temperature resin, a material with a rigidity close to aluminium but without generating eddy currents to maintain signal purity.

The mid/bass drivers' magnet system also includes an aluminium compensation ring, which minimises impedance variations. Castle claims this will create an open and expressive midrange.

Castle Windsor Earl

(Image credit: Castle)

There's some clever engineering elsewhere, too. The treble unit's voice coil includes a copper cap which reduces distortion and intermodulation, creating more detail, while the cabinet's MDF panels are separated by a thin layer of specially engineered acoustic glue to dampen resonance in the midrange.

Rigidity at lower frequencies is achieved by point-to-point cabinet bracing. Both Windsor models use a 4th order LKR (Linkwitz-Riley) crossover which prevents distortion.

Finally, the wood-veneer finish is a hallmark of Castle's speakers. The Windsors' cabinets sport walnut or mahogany veneers sourced from sustainable timbers – only deep-figured slices are used, cut from real trees rather than reconstituted wood. 

The Castle Windsor Earl cost £3850 per pair (£4250 with stands) while the Windsor Duke are £4500 (£5000 with stands). Internationally, they only ship with stands with the Windsor Earl costing $5250 / AU$8000 and the Duke retailing for $6250 / AU$9250.


Read our British Hi-Fi Week 2023 news, features and reviews (so far)

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Joe Svetlik

Joe has been writing about tech for 17 years, first on staff at T3 magazine, then in a freelance capacity for Stuff, The Sunday Times Travel Magazine, Men's Health, GQ, The Mirror, Trusted Reviews, TechRadar and many more (including What Hi-Fi?). His specialities include all things mobile, headphones and speakers that he can't justifying spending money on.