GoldenEar T66 Loudspeaker Lab Report

Lab Report

While our measured sensitivity(s) for GoldenEar's T66 of 89.6dB (500Hz-8kHz) and 89.8dB/1kHz are shy of the rated 91dB, the forward response [see Graph 1] is commendably flat from bass to midrange. There's a slight dip in the upper midrange before a strong recovery in the treble that contributes to the high ±4.0dB and ±5.2dB response errors, respectively, just as pair matching is also slightly wayward at 1.7dB (all re. 200Hz-20kHz). Off-axis listening will suppress the boosted treble but we've seen the closely-spaced ripples before [HFN Jun & Nov '19], caused by a reflection within the speaker and seen as a peak in the impulse response at a delay of 0.5msec, equivalent to a path length of 17cm. Associated resonances are also visible on an otherwise 'clean' CSD waterfall [see Graph 2] – GoldenEar's trademark fixed, curved, perforated grille remaining the chief suspect here.

The T66's impedance rises from 3.5ohm/140Hz to 17ohm/20Hz (and 20ohm/5Hz) as the active subwoofer takes over but remains sub-7ohm from 140Hz-100kHz. The 3.05ohm/360Hz minimum means the T66 meets GoldenEar's 4ohm specification but the big negative swing in phase angle of –54°/85Hz adds to a slightly tougher EPDR of 1.3ohm/128Hz (the active bass xover). Meanwhile, this active bass section further reduces distortion (sub-0.1% at 90dB SPL) in what is already an impressively 'low distortion' speaker design, the two 5x9in 'quadratic' woofers peaking at 72Hz and working with dual ABRs, tuned to 31Hz, to deliver a deep, diffraction-corrected 28Hz bass extension (–6dB re. 200Hz). The lower active woofer also utilises boundary reinforcement with the floor to achieve this result. PM


Response including nearfield summed active drivers/ABRs [green], freefield corrected to 1m at 2.83V [yellow], ultrasonic [pink]. Left, black; right, red

GoldenEar T66_Waterfall_L_35dB

The cabinet is well behaved at LF but various driver/structural resonances are seen >3kHz

Sensitivity (SPL/1m/2.83V – 1kHz/Mean/IEC) 89.8dB / 89.6dB / 88.4dB
Impedance modulus: minimum & maximum (20Hz–20kHz) 3.05ohm @ 360Hz, 17.0ohm @ 20Hz
Impedance phase: minimum & maximum (20Hz–20kHz) –54° @ 85Hz, +17° @ 1000Hz
Pair matching/Resp. error (200Hz–20kHz) 1.7dB/ ±4.0dB/±5.2dB
LF/HF extension (–6dB ref 200Hz/10kHz) 28Hz / 30.9kHz/31.0kHz
THD 100Hz/1kHz/10kHz (for 90dB SPL/1m) 0.08% / 0.2% / 0.25%
Dimensions (HWD) / Weight (each) 1241x300x432mm / 27kg
Price £6249 (+£250 red finish)

The Quest Group (dba GoldenEar Technology)
Supplied by: AudioQuest UK
01249 848 873