• L/R Sensitivity: 87 dB from 500 Hz to 2 kHz

• Center Sensitivity: 89.5 dB from 500 Hz to 2 kHz

• Surround Sensitivity: 85.5 dB from 500 Hz to 2 kHz

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

The Four's listening-window response (a five-point average of axial and +/–15-degree horizontal and vertical responses) measures +0.75/–2.67 decibels from 200 hertz to 10 kilohertz. The –3-dB point is at 42 Hz, and the –6-dB point is at 35 Hz. Impedance reaches a minimum of 5.24 ohms at 145 Hz and a phase angle of –69.50 degrees at 61 Hz.

The Three C's listening-window response measures +0.96/–1.98 dB from 200 Hz to 10 kHz. An average of axial and +/–15-degree horizontal responses measures +1.26/–1.86 dB from 200 Hz to 10 kHz. The –3-dB point is at 76 Hz, and the –6-dB point is at 63 Hz. Impedance reaches a minimum of 4.57 ohms at 14.8 kHz and a phase angle of –42.20 degrees at 92 Hz.

The Three's listening-window response measures +1.05/–3.68 dB from 200 Hz to 10 kHz. The –3-dB point is at 69 Hz, and the –6-dB point is at 55 Hz. Impedance reaches a minimum of 4.77 ohms at 143 Hz and a phase angle of –48.61 degrees at 76 Hz.—MJP