Loudspeakers

The man behind Purifi’s range of innovative drive units, Lars Risbo, is not only the brand’s co-founder but also the designer of the legendary TacT Millennium amplifier, one of the first genuinely digital Class D amplifiers to emerge in the 1990s and forerunner of the Lyngdorf models of today. Turning his hand to improving the mechanical and electromagnetic parameters of the classic moving-coil driver, Lars’ left-field thinking, and not a little computer modelling, has been realised in these small-cone, extended-stroke woofers. Called Ushindi (Swahili for victory), these drivers combine a deep magnet, voice-coil and suspension with the exceedingly novel ‘NeutralSurround’ to ‘exceed the bass performance of a large-cone/short-stroke driver’.

This new surround profile endows the Ushindi’s smaller cone with a longer, more linear throw – also extending its reach into the midrange – while working with the suspension spider to prevent the voice coil position from modulating the motor’s force factor. Low THD and IMD are promised as a result [see PM's Lab Report]. Specifically, one PTT4.0X04-NLC-02 woofer is deployed in the Clarity 4.2 supplemented by two matching PTT40PR-NL2-03 passive radiators, specially modified here with slightly heavier membranes to push the tuned resonance frequency that bit lower. PM