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Two channels driven continuously into 8-ohm loads: 0.2% distortion at 25.6 watts 1% distortion at 28.7 watts

Two channels driven continuously into 4-ohm loads: 0.2% distortion at 28.9 watts 1% distortion at 34.2 watts

This graph shows the quasi-anechoic (employing close-miking of all woofers) frequency response of the ST-670 satellites (purple trace) and ASW-670 subwoofer (blue trace). The passive loudspeaker was measured at a distance of 1 meter with a 2.83-volt input.

The ST-670's listening-window response (a five-point average of axial and +/–15-degree horizontal and vertical responses) measures +3.64/–0.98 decibels from 200 hertz to 10 kilohertz. An average of axial and +/–15-degree horizontal responses measures +4.61/–0.78 dB from 200 Hz to 10 kHz. The –3dB point is at 136 Hz, and the –6dB point is at 115 Hz. Impedance reaches a minimum of 7.12 ohms at 299 Hz and a phase angle of –38.86 degrees at 170 Hz. Sensitivity averages 81.5 dB from 500 Hz to 2 kHz.

The ASW-670's close-miked response, normalized to the level at 80 Hz, indicates that the lower –3dB point is at 50 Hz and the –6dB point is at 44 Hz. The upper –3dB point is at 134 Hz with the Crossover control set to maximum.

Crosstalk at 1 kHz driving 2.83 volts into an 8-ohm load was –70.45 dB left to right and –68.72 dB right to left. THD+N from the amplifier was less than 0.030% at 1 kHz when driving 2.83 volts into an 8-ohm load. The signal-to-noise ratio with 2.83 volts driving an 8-ohm load from 10 Hz to 24 kHz with "A" weighting was –93.19 dBrA.—MJP