Loudspeakers

The proof of DALI’s ‘Wide Dispersion Sound Design Principle’ is revealed by its off-axis responses which are more uniform from 0° (on-axis) to ±15° and ±30° [grey and orange traces, Graph 1]. On-axis, the response errors are ±3.4dB and ±3.6dB, respectively, but this tightens up to just ±2.45dB (200Hz-20kHz) at ±30° as the 4dB dip at the bottom of the 35mm tweeter’s range (3-4kHz) starts to fill in. Heard ±30° off axis the Epikore 11 is ‘flat’ to within a tight ±1.3dB from 200Hz-10kHz. Moreover, the on-axis midband driver resonances are less apparent off-axis, delivering a far cleaner CSD waterfall [Graph 2]. Also, the grille is designed so that its fine fabric is stretched across the tops of the driver frames, minimising diffraction effects [blue trace, Graph 1].

Bass output is prodigious but complex to ‘model’ [green area, Graph 1] – both ports are tuned to a subsonic 18Hz while the woofers peak at 93Hz, although the upper pair rolls into the midrange at a lower frequency, with a ‘cleaner’ output, while the lower pair covers a wider 300Hz bandwidth and with low-level cabinet modes revealed via the lower port at 330Hz, 620Hz and 1.1kHz. The upshot is a corrected bass extension of 17Hz (–6dB re. 200Hz) and very low bass THD of <0.1% (90dB SPL).

Sensitivity, measured at 92dB/1kHz and 90.3dB/500Hz-8kHz, is significantly higher than DALI’s rated 89dB but this, and the awesome bass extension, are not ‘for free’ – the load is a uniform sub-8ohm above 100Hz, albeit with a modest 3.7ohm/805ohm minimum. However, while the minimum EPDR of 1.58ohm/68Hz is manageable, the sub-3ohm stretches through the low bass, the midrange and high treble will keep your amp on its toes. PM