TRIANGLE SIGNATURE ALPHA

摘要

Triangle claims 92dB sensitivity for the Signature Alpha but our pink noise figure of 90.1dB suggests this is ambitious, although still sufficient to rank as above average. Nominal impedance is 8ohm but the specified minimum of 3.3ohm indicates a 4ohm rating is more appropriate, and our measured minimum modulus of 3.5ohm supports this. Impedance phase angles are sufficiently high to drop the EPDR (equivalent peak dissipation resistance) to a minimum of 1.7ohm at 90Hz - a typical result for a modern floorstander of this size and sensitivity. As the horn-loaded tweeter is located above typical seated ear level, initial frequency response measurements were taken on the axis of the midrange unit and then at a height mid-way up the front baffle. The responses [Graph 1, below] are for the former position and show a rise in output above 8kHz but the response through bass and midrange is flatter than at the lower listening height. Mid-way up the baffle, the high treble excess is curbed but a narrow dip of about 4.5dB is introduced at 2.2kHz. Response errors on the midrange axis were ±3.1dB and ±3.7dB respectively (200Hz-20kHz), and these figures could perhaps be improved slightly off-axis. Pair matching was less satisfactory at ±2.0dB but the largest disparity, at 1.7kHz, was quite narrowband. Without this, the error would have been a better ±1.3dB. Diffraction-corrected near-field LF measurements showed the bass extension to be 49Hz (-6dB re. 200Hz), again typical for this class of loudspeaker. Origins of the response ripples between 1 kHz and 3kHz are clear from the cumulative spectral decay waterfall [Graph 2] which shows two obvious resonances here.