Bookshelf Speaker Reviews

L/R Sensitivity: 87.5 dB from 500 Hz to 2 kHz

Center Sensitivity: 88 dB from 500 Hz to 2 kHz

Surround Sensitivity: 86 dB from 500 Hz to 2 kHz

This graph shows the quasi-anechoic (employing close-miking of all woofers) frequency response of the Zensor 5 L/R (purple trace), HSU VTF-1 MK2 subwoofer (blue trace), Zensor Vokal center channel (green trace), and Zensor 1 surround (red 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 Zensor 5’s listening-window response (a five-point average of axial and +/–15-degree horizontal and vertical responses) measures +2.52/–4.70 decibels from 200 hertz to 10 kilohertz. The –3dB point is at 53 Hz, and the –6dB point is at 38 Hz. Impedance reaches a minimum of 5.57 ohms at 230 Hz and a phase angle of –45.98 degrees at 98 Hz.

The Zensor Vokal’s listening-window response measures +2.15/–3.22 dB from 200 Hz to 10 kHz. An average of axial and +/–15-degree horizontal responses measures +2.41/–4.21 dB from 200 Hz to 10 kHz. The –3dB point is at 76 Hz, and the –6dB point is at 57 Hz. Impedance reaches a minimum of 5.54 ohms at 221 Hz and a phase angle of –46.66 degrees at 111 Hz.

The Zensor 1’s listening-window response measures +3.73/–2.59 dB from 200 Hz to 10 kHz. The –3dB point is at 90 Hz, and the –6dB point is at 63 Hz. Impedance reaches a minimum of 5.67 ohms at 224 Hz and a phase angle of –52.83 degrees at 120 Hz.

The VTF-1 MK2’s close-miked response, normalized to the level at 80 Hz, indicates that the lower –3dB point is at 25 Hz and the –6dB point is at 20 Hz. The upper –3dB point is at 150 Hz with the Crossover switch set to Out.—MJP