Loudspeakers

As per standard DALI practice, the Sonik 9’s off-axis directivity is engineered to deliver the flattest mid/presence response when firing straight down the room, leaving the listener 10-20° off the main axis [blue trace, Graph 1]. The forward response has a 5dB step up once the dome tweeter gets into its stride from 3-10kHz but this is exaggerated further if you listen directly on the HF axis or, slightly less so, just above the top mid/bass axis [black/red traces, Graph 1]. In either case the response errors amount to a modest ±3.3dB and ±3.5dB, respectively, with a very tight 0.6dB pair matching. Incidentally, you really don’t want to use the grille for anything other than keeping dust at bay [grey trace, Graph 1]. The mid/presence dip also means that DALI’s 90dB sensitivity rating is not met in practice – so 87.8dB/2.83V/1m (re. 1kHz) and 88.5dB (re. 500Hz-8kHz) are more realistic figures.

That said, DALI’s specified 4ohm impedance truly reflects the 4.18ohm/135Hz minimum (it does dip to 4.05ohm from 14kHz-20kHz but there’s limited signal content here). Moreover, the principal swings in impedance phase occur between 10-500Hz ensuring the minimum EPDR – the ‘toughest’ drive – occurs at 2.0ohm/97Hz. DALI’s ‘2.5+0.5 way’ denomination reflects the 2.1kHz crossover to the 29mm dome tweeter and 14kHz to the planar super tweeter while, at 400Hz, the lower of the three mid/woofers rolls away, leaving the upper two cones with a boosted 500-2kHz output. Bass evidently has some ‘oomph’ – the three ports are tuned to 31Hz, while also exposing a strong 700Hz/1.4kHz quaterwave mode, but together with the woofer trio they deliver an impressive 32Hz bass extension (–6dB re. 200Hz). PM