TEST BENCH

DOLBY DIGITAL PERFORMANCE All data were obtained from various test DVDs using 16-bit dithered-test signals, which set limits on measured distortion and noise performance. Reference input level is -20 dBFS, and reference output is 1 watt into 8 ohms. Volume setting for reference level was -6.5. All level trims at zero, except for subwoofer-related tests, and all speakers were set to "large," with subwoofer on. All are worst-case figures where applicable.

Output at clipping (1 kHz into 8/4 ohms) 1 channel driven: 189/270 W (22.8/24.3 dBW) 5 channels driven (8 ohms): 100 W (20 dBW) 7 channels driven (8 ohms): 88 W (19.4 dBW)

Distortion at 1 watt (THD+N, 1 kHz) 8/4 ohms: 0.02/0.03% Noise level (A-wtd): -75.7 dB Excess noise (with sine tone) 16-bit (EN16): 0.4 dB Frequency response: 20 Hz to 20 kHz +0, -0.1 dB

MULTICHANNEL PERFORMANCE, ANALOG INPUT Reference input and output level is 200 >mV; volume setting for reference output level was -5. Distortion (THD+N, 1 kHz, 8 ohms): 0.01% Noise level (A-wtd): -89.1 Frequency response: <10 Hz to 200 kHz +0, -2.3 dB

STEREO PERFORMANCE, DIGITAL INPUT Reference level is -20 dBFS; all level trims at zero. Volume setting for reference level was -4.

Output at clipping (1 kHz, 8/4 ohms, both channels driven): 150/245 W (21.8/23.9 dBW) Distortion at reference level: 0.02% Linearity error (at -90 dBFS): 0.1 dB Noise level (A-wtd): -75.5 dB with 96-kHz/24-bit signals: -79.1 dB Excess noise (with/without sine tone) 16-bit (EN16): 0.4/0.3 dB quasi-20-bit (EN20): 9.0/8.5 dB Noise modulation: 1.3 dB Frequency response: <10 Hz to 20 kHz +0.3, -0 dB with 96-kHz/24-bit signals: <10 Hz to 23 kHz +0, -0.3 dB (-6 dB at 26 kHz)

BASS-MANAGEMENT PERFORMANCE Measured results obtained with Dolby Digital test signals. Subwoofer-output frequency response (crossover set to 80 Hz): 24 dB/octave (approx.) above -6-dB rolloff point of 81 Hz High-pass-filter frequency response (crossover set to 80 Hz): 12 dB/octave below -3-dB rolloff point of 80 Hz Maximum unclipped subwoofer output (trim at 0): 5.2v Subwoofer distortion (from 6-channel, 30-Hz, 0-dBFS signal; subwoofer trim set to 0): 0.2% Crossover consistency: bass crossover frequency and slope were consistent for all sources and formats Signal-format consistency: consistent for all applicable formats Speaker size selection: all channels can be set to "small" Speaker-distance compensation: available for all main channels.

Yamaha's RX-V3900 proved exemplary on the test bench. Amplifier power was impressive, beating the 140-watt spec in stereo, showing roughly 2-dBW gains into 4-ohm loads without complaint, and maintaining 100 watts all around with 5 channels driven (and nearly as much with 7 channels stressed). Noise and distortion, and D-to-A linearity, were all virtually perfect. Only two anomalies showed up: Dithered noise with 96/24 PCM signals was a bit disappointing at -79.1 dBW, and analog domain noise at the multichannel inputs, though 10 dB better, was similarly a bit short of the best we've seen. (A bit of analog-domain contribution from the receiver's output circuitry was the likely culprit.) Our results still indicate a real-world dynamic range perhaps 10 dB better than typical loudspeaker systems can exploit, even in very quiet listening conditions, however. Curiously, the RX-V3900 cut off output of 96/24 PCM signals quite sharply above around 22 kHz in both Stereo and Pure Direct modes.