Triangle Magellan Cello 40th Anniversary Loudspeaker Lab Report

Lab Report

Measured midway between the TZ2900 horn tweeter and 160mm paper midrange cone or, indeed, directly on the horn's axis, the Magellan Cello's forward response shows a ~5dB dip in output at 1.5kHz [Graph 1] that's also reflected in a mode on the CSD waterfall [Graph 2]. We saw similar in the Alpha Signature [HFN May '15], possibly due to a mistermination at the mid's pleated surround. Either way, this is at the top of the mid unit's 350Hz-2.5kHz range before it crosses over to the (phase inverted) tweeter, and it contributes to the ±4.1dB and ±4.0dB responses errors alongside the ~6.3dB dip in output at 16.3kHz. The latter is just prior to the magnesium tweeter dome's primary resonance at 24kHz. These dips aside, the trend falls within far 'flatter' ±1.7dB limits, while the pair matching is a tight 0.6dB (all re. 200Hz-20kHz). The effect of the grille is particularly disruptive through mid and presence [blue trace, Graph 1] suggesting it should always be removed before 'serious' listening.

The 90.8dB/1kHz sensitivity meets Triangle's 90dB spec. but dips slightly to 90.3dB over a more representative 500Hz-8kHz range. Triangle's ambitious –3dB/35Hz bass claim is supported by those two 160mm 'sandwich' bass cones but their 57-230Hz bandwidth (–6dB), supplemented by a vigorous 32Hz port tuning, actually brings the extension in closer to 50Hz (–3dB re. 200Hz, or 32Hz/–6dB). This is still impressive, and achieved with ±50° swings in impedance phase through the bass and a sub-4ohm load from 85-350Hz, although the minimum 1.3ohm/89Hz (sub-4ohm, 68Hz-1.3kHz) EPDR is not especially tough for the sensitivity and bass extension on offer here. PM


Response inc. nearfield summed driver/port [green], freefield corrected to 1m at 2.83V [yellow], ultrasonic [pink]. Left, black; right, red; w. grille, blue


Cabinet modes are well controlled but a response mode, and harmonics, at 1.5kHz is clear

Sensitivity (SPL/1m/2.83V – 1kHz/Mean/IEC) 90.8dB / 90.3dB / 87.8dB
Impedance modulus: minimum & maximum (20Hz–20kHz) 3.3ohm @ 113Hz, 17.1ohm @ 64Hz
Impedance phase: minimum & maximum (20Hz–20kHz) –48° @ 100Hz, +51° @ 25Hz
Pair matching/Resp. error (200Hz–20kHz) 0.6dB/ ±4.1dB/±4.0dB
LF/HF extension (–6dB ref 200Hz/10kHz) 32Hz / 15.2kHz/16.3kHz
THD 100Hz/1kHz/10kHz (for 90dB SPL/1m) 0.2% / 0.25% / 1.3%
Dimensions (HWD) / Weight (each) 1140x425x370mm / 39kg
Price £11,000

Triangle Distribution France
Bordeaux, France
Supplied by: SCV Electronics Ltd, Herts
03301 222500