Test Bench: Yamaha RX-V1800 A/V Receiver
Yamaha's RX-V1800 yielded the fine technical performance usual from the firm's A/V receivers. Power exceeded its specs by a good margin and bettered 100 watts all around, even with 5 channels driven. The unit's power supply appeared to run out of current when 2 more channels were added, however, since the 7-channel result dropped by nearly 3 dB, to 55 watts-a non-issue in the real world., where program signals never demand this level of stability. Yamaha equips its receiver with a software setup switch for speakers of 6-ohms or lower, which effectively limits power to about two thirds.
Frequency response, distortion, and D/A linearity were uniformly excellent, and crossover responses were all bang on the numbers, with nicely accurate slopes-not always the case. PCM and Dolby Digital noise were very good, if a dB or 2 shy of the best we've seen, although S/N on the analog-multichannel inputs was truly superior. I note that the analog input was a good bit more sensitive than the digital ones (re: our reference levels of -20 dBFS or 200 mV for 1 watt output), so listeners who switch from the latter to the former without adjusting the volume could be in for a roughly 10 dB surprise. While this sounds like a lot, most characterize it as only about subjectively "twice as loud" or so.
DOLBY DIGITAL PERFORMANCE
All data were obtained from various test DVDs using 16-bit dithered test signals, which set limits on measured distorting 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. All level trims at zero, except for subwoofer-related tests, all speakers were set to "large," subwoofer on. All are worst-case figures where applicable.
Output at clipping (1 kHz into 8/4 ohms) 1 channel driven: 158/281 W (22/24.5 dBW)* 5 channels driven (8 ohms): 103 W (20.1 dBW) 7 channels driven (8 ohms): 55 W (17.4 dBW) Distortion at 1 watt (THD+N, 1 kHz) 8/4 ohms: 0.02/0.03% Noise level (A-wtd): -73.4 dB Excess noise (with sine tone) 16-bit (EN16): 0.9 dB Frequency response: 20 Hz to 20 kHz +0, -0.2 dB
MULTICHANNEL PERFORMANCE, ANALOG INPUT
Reference input and output level is 200 mV; volume setting for reference output level was -14. Distortion (THD+N, 1 kHz, 8 ohms): 0.008% Noise level (A-wtd.): -90.1 Frequency response: <10 Hz to 166 kHz +0, -3 dB
STEREO PERFORMANCE, DIGITAL INPUT
Reference level is -20 dBFS; all level trims at zero. Volume setting for reference level was -3.
Output at clipping (1 kHz, 8/4 ohms, both channels driven): 150/237 W (21.8/23.7 dBW)* Distortion at reference level: 0.02% Linearity error (at -90 dBFS): 0.2 dB Noise level (A-wtd): -74.8 dB with 96-kHz/24-bit signals: -85.4 dB Excess noise (with/without sine tone) 16-bit (EN16): 0.6/0.8 dB quasi-20-bit (EN20): 13.3/12.1 dB Noise modulation: 0.6 dB Frequency response: <10 Hz to 20 kHz +0, -0.3 dB with 96-kHz/24-bit signals: <10 Hz to 44 kHz +0, -3 dB
*With receiver's software setup switch at 8 ohms. With switch at 6 ohms, power was limited to about 90 and 160 watts (19.5/22 dBW) into 8 ohms and 4 ohms respectively.
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 80 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): 6.8v Subwoofer distortion (from 6-channel, 30-Hz, 0-dBFS signal; subwoofer trim set to 0): 0.3% 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.