Tower Speaker Reviews

HT Labs Measures
L/R Sensitivity: 91 dB from 500 Hz to 2 kHz
Center Sensitivity: 89 dB from 500 Hz to 2 kHz
Surround Sensitivity: 88 dB from 500 Hz to 2 kHz

This graph shows the quasi-anechoic (employing close-miking of all woofers) frequency response of the Motion 40 L/R (purple trace), Motion 30 center channel (green trace), Motion 15 surround (red trace), and Dynamo 1000 subwoofer (blue trace). All passive loudspeakers were measured with grilles at a distance of 1 meter with a 2.83-volt input and scaled for display purposes.

The Motion 40’s listening-window response (a five-point average of axial and +/–15-degree horizontal and vertical responses) measures +2.25/–4.34 decibels from 200 hertz to 10 kilohertz. The –3-dB point is at 48 Hz, and the –6-dB point is at 40 Hz. Impedance reaches a minimum of 3.48 ohms at 111 Hz and a phase angle of –44.04 degrees at 69 Hz.

The Motion 30’s listening-window response measures +2.70/–3.86 dB from 200 Hz to 10 kHz. An average of axial and +/–15-degree horizontal responses measures +2.68/–4.75 dB from 200 Hz to 10 kHz. The –3-dB point is at 86 Hz, and the –6-dB point is at 71 Hz. Impedance reaches a minimum of 3.94 ohms at 53 Hz and a phase angle of –33.69 degrees at 41 Hz.

The Motion 15’s listening-window response measures +1.54/–2.84 dB from 200 Hz to 10 kHz. The –3-dB point is at 83 Hz, and the –6-dB point is at 69 Hz. Impedance reaches a minimum of 3.78 ohms at 2.0 kHz and a phase angle of –61.05 degrees at 136 Hz.

The Dynamo 1000W’s close-miked response, normalized to the level at 80 Hz, indicates that the lower –3-dB point is at 23 Hz and the –6-dB point is at 20 Hz. The upper –3-dB point is at 131 Hz with the Crossover switch set to Bypass.—MJP