Loudspeakers

Measuring a speaker like the Iota Xplorer poses the difficulty of which axis to use. With its upper bass-midrange driver and tweeter angled upwards from the horizontal, this unusual speaker has a variable listening axis according to how far away from it you sit. I performed our measurements, as usual, 1m away on the tweeter axis but we have to take account of the fact that it will rarely if ever be listened to in this way [see Graph 1]. Below this axis we can expect the prominent treble output to fall away but so will the upper end of the bass-mid output, so integration of the two will never be the smoothest. The shelved-up then peaked, then precipitous, treble results in rather high response errors of ±5.1dB and ±5.6dB for the pair (200Hz-20kHz), and also raises the pink noise sensitivity to 89.6dB, 2.6dB above Neat's specification. But you can see from Graph 1 that 87dB is about the sensitivity of the bass-mid driver, and for that reason it is a justifiable figure.

Pair matching over the same frequency range was a little disappointing at ±1.7dB but the responsibility for that lies not with Neat's own P1-R3 bass/midrange driver – below 3kHz the pair matching is ±0.8dB – but with the rather wayward AMT tweeter. Our measured bass extension of 75Hz (–6dB re. 200Hz) may seem disappointing too, for a speaker using isobaric bass loading [see Isobaric Loading sidebar], but in practice boundary gain from the floor and wall behind will add significantly to the LF capability. Impedance is quite amplifier-friendly with a minimum modulus of 4.3ohm and minimum EPDR of 2.4ohm at 54Hz. The CSD waterfall [Graph 2] shows a clump of treble resonances between about 3kHz and 9kHz. KH

Sensitivity (SPL/1m/2.83Vrms – Mean/IEC/Music): 92.1dB / 89.6dB / 89.0dB
Impedance modulus min/max (20Hz–20kHz): 4.3ohm @ 20Hz / 39.3ohm @ 1.9kHz
Impedance phase min/max (20Hz–20kHz): –55° @ 3.8kHz / 45° @ 814Hz
Pair matching/Response Error (300Hz–20kHz): ±1.7dB / ±5.1dB/±5.6dB
LF/HF extension (–6dB ref 200Hz/10kHz): 75Hz / 19.5kHz/19.1kHz
THD 100Hz/1kHz/10kHz (for 90dB SPL/1m): 1.3% / 0.2% / 0.1%
Dimensions (HWD) / Weight: 740x299x220mm / 18kg
Price: £3495