Totem Acoustic Bison Monitor Loudspeaker Lab Report

Lab Report

While not quite the 8ohm specified by Totem, the Bison's minimum impedance modulus is still a very comfortable 5.4ohm/228Hz (warranting a 6ohm nominal rating) which, combined with equally 'easy' –39.7°/96.5Hz and +43.3°/1.09kHz phase angles, results in a minimum EPDR of 2.8ohm/52Hz. However, glitches in the impedance/phase curves at 420Hz, 770Hz and 920Hz presage a boost in the Bison's forward response of ~3dB at 800Hz-1.3kHz [see Graph 1] which, in turn, is reflected in resonance modes seen on the CSD waterfall plot [see Graph 2]. The latter are likely linked to the huge 76mm dustcap, or a cone/surround mistermination within the 133mm bass unit, but the overall response is otherwise very even, if slightly upturned towards the presence/treble. The grille produces a ~3dB drop in output at ~5kHz [blue trace, Graph 1]. Otherwise, pair matching is an exceptionally fine 0.4dB with response errors amounting to ±3.4dB and ±3.3dB, respectively, not including the 28kHz peak from the large (33mm) soft treble dome which pushes the Bison's HF response out to a respectable 34kHz (–6dB re. 10kHz).

Totem rates the Bison's sensitivity at 87dB but the 'bump' in response rather conveniently boosts the 1kHz figure to 87.8dB! However, figures of 84.8dB (500Hz-8kHz) and the IEC (perceptually)-wtd 83.0dB give a more realistic idea of perceived 'loudness'. Nevertheless, for a box of this size, impedance and sensitivity, distortion remains low at <0.7% (100Hz-10kHz re. 90dB SPL) while bass extension, aided by the 60Hz-600Hz (–6dB) woofer bandwidth and low 35Hz port tuning, reaches down to a respectable 41Hz (–6dB re. 200Hz) or 67Hz (–6dB re. 1kHz). 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

Totem Acoustic Bison_Waterfall_L_35dB

The main bass driver modes at ~1kHz are seen on the response [Graph 1] but presence/treble is clean

Sensitivity (SPL/1m/2.83V – 1kHz/Mean/IEC) 87.8dB / 84.8dB / 83.0dB
Impedance modulus: minimum & maximum (20Hz–20kHz) 5.40ohm @ 228Hz, 25.3ohm @ 2.59kHz
Impedance phase: minimum & maximum (20Hz–20kHz) –39.7° @ 96.5Hz, +43.3° @ 1.09kHz
Pair matching/Resp. error (200Hz–20kHz) 0.4dB / ±3.4dB/±3.3dB
LF/HF extension (–6dB ref 200Hz/10kHz) 41Hz / 34.7kHz/34.2kHz
THD 100Hz/1kHz/10kHz (for 90dB SPL/1m) 0.65% / 0.15% / 0.55%
Dimensions (HWD) / Weight (each) 850x171x243mm / 5kg
Price £2495

Totem Acoustic
Montreal, Quebec, Canada
Supplied by: Redline Scotland Ltd, Essex, UK
01268 858222