Bookshelf Speaker Reviews

L/R Sensitivity: 90 dB from 500 Hz to 2 kHz

Center Sensitivity: 90 dB from 500 Hz to 2 kHz

Surround Sensitivity: 87 dB from 500 Hz to 2 kHz

This graph shows the quasi-anechoic (employing close-miking of all woofers) frequency response of the GTC77 L/R (purple trace), GTC77 horizontal center channel (green trace), GTC55 surround (red trace), and GTC Sub 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 GTC77’s listening-window response (a five-point average of axial and +/–15-degree horizontal and vertical responses) measures +1.65/–3.14 decibels from 200 hertz to 10 kilohertz. The –3-dB point is at 49 Hz, and the –6-dB point is at 39 Hz. Impedance reaches a minimum of 5.39 ohms at 511 Hz and a phase angle of –30.13 degrees at 96 Hz.

The GTC77’s listening-window response in horizontal mode measures +1.49/–3.39 dB from 200 Hz to 10 kHz. An average of axial and +/–15-degree horizontal responses measures +1.63/–2.93 dB from 200 Hz to 10 kHz. The –3-dB point is at 49 Hz, and the –6-dB point is at 39 Hz. Impedance reaches a minimum of 5.39 ohms at 511 Hz and a phase angle of –30.13 degrees at 96 Hz.

The GTC55’s listening-window response measures +1.29/–3.64 dB from 200 Hz to 10 kHz. The –3-dB point is at 49 Hz, and the –6-dB point is at 42 Hz. Impedance reaches a minimum of 5.70 ohms at 3.3 kHz and a phase angle of –43.22 degrees at 111 Hz.

The GTC Sub’s close-miked response, normalized to the level at 80 Hz, indicates that the lower –3-dB point is at 22 Hz and the –6-dB point is at 20 Hz. The upper –3-dB point is at 143 Hz with the Sub Filter control set to maximum. —MJP