Loudspeakers

There are various ways to bend the rule of loudspeaker physics which says that small speakers are insensitive. You can increase cabinet internal volume, lower impedance or curtail bass extension. With the Diamond 11.1, which has a high sensitivity for its size of 87dB (the specified figure and exactly what we measured on pink noise, 200Hz-20kHz), Wharfedale has opted for quite low impedance and has curtailed bass extension too. The 11.1 is specified as '8 ohms compatible' – a meaningless phrase – but with a minimum modulus of 3.5ohm its nominal figure should be 4ohm. Impedance phase angles are quite high but sufficiently well controlled that the minimum EPDR is 1.9ohm at 162Hz, a little higher than we measure from many modern loudspeakers, although a further dip to 2.0ohm at 656Hz compromises that. So the 11.1 doesn't classify as particularly easy to drive.

Because its reflex port vents though a narrow gap between the cabinet proper and its integral plinth this isn't the easiest speaker to which to apply the nearfield bass measurement technique, but our diffraction-corrected result shows the bass extension to be a high 87Hz (–6dB re. 200Hz), so boundary gain will certainly be needed to add heft. The on-axis frequency response [Graph 1], measured on the tweeter axis shows a mild shelving-down of the presence band and excess treble in the highest audible octave. But the response errors are modest at ±3.2dB and ±2.3dB respectively. Pair matching error is a little high at ±1.5dB, the largest disparities occurring above 2.9kHz. The CSD waterfall [Graph 2] is clean but for a resonance at 3.2kHz, absent from the other of the pair. KH

Sensitivity (SPL/1m/2.83Vrms – Mean/IEC/Music): 87.8dB / 87.0dB / 86.5dB
Impedance modulus min/max (20Hz–20kHz): 3.5ohm @ 284Hz / 21.0ohm @ 87Hz
Impedance phase min/max (20Hz–20kHz): –50° @ 125Hz / 47° @ 875Hz
Pair matching/Response Error (200Hz–20kHz): ±1.5dB / ±3.2dB / ±2.3dB
LF/HF extension (–6dB ref 200Hz/10kHz): 87Hz / 30.0kHz / 38.0kHz
THD 100Hz/1kHz/10kHz (for 90dB SPL/1m): 2.1% / 0.4% / 0.3%
Dimensions (HWD): 310x194x285mm
Price: £270