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. 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: 141/240 W (21.5/23.8 dBW)
5 channels driven (8 ohms): 98 W (19.9 dBW)
7 channels driven (8 ohms): 90 W (19.5 dBW)
Distortion at 1 watt (THD+N, 1 kHz)
8/4 ohms: 0.03/0.03%
Noise level (A-wtd): -76.4 dB
Excess noise (with sine tone)
16-bit (EN16): 0.7 dB
Frequency response: 20 Hz to 20 kHz +0.6, -0.1 dB
MULTICHANNEL PERFORMANCE, ANALOG INPUT
Reference input and output level is 200 mV; volume setting for reference output level was -3.
Distortion (THD+N, 1 kHz, 8 ohms): 0.02%
Noise level (A-wtd): -87.6
Frequency response: <10 Hz to 142 kHz +0, -2.4 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): 128/188 W (21.1/22.7 dBW)
Distortion at reference level: 0.03%
Linearity error (at -90 dBFS): 6.4 dB
Noise level (A-wtd): -77.4 dB
with 96-kHz/24-bit signals: -81.8 dB
Excess noise (with/without sine tone)
16-bit (EN16): 1.0/2.3 dB
quasi-20-bit (EN20): 13.4/13.9 dB
Noise modulation: 3.0 dB
Frequency response: <10 Hz to 20 kHz +0.9, -0.25 dB
with 96-kHz/24-bit signals: <10 Hz to 46 kHz +0, -3 dB
BASS-MANAGEMENT PERFORMANCE
Measured results obtained with Dolby Digital test signals.
Subwoofer-output frequency response (crossover set to 80 Hz): 24 dB/octave 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 81 Hz
Maximum unclipped subwoofer output (trim at 0): 8.1v
Subwoofer distortion (from 6-channel, 30-Hz, 0-dBFS signal; subwoofer trim set to 0): 0.03%
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.
Test results for Marantz's SR6004 A/V receiver turned out to be essentially identical to those of the SR6003 we looked at almost two years ago. That translates to substantial power: The SR6004 closely approached its 110-watts-per-channel ratings even on 5-channel tests and still delivered a very satisfying 90 watts with all seven amplifiers at their clipping points. Frequency response and distortion were generally very good as well; however, the SR6004 departed from its progenitor in showing a slight half-dB or so hump in response from 50 Hz to around 500 Hz. (I have no explanation for this but do not see it as significant, especially since it falls in the range where most systems will be integrating subwoofer output, with in-room levels ultimately determined by ear/to taste anyway.) Noise and linearity results again were a decibel or so shy of the theoretical limits to the negative, suggesting a least-significant-bit error of moderate magnitude in the digital-to-analog conversion system. This is might in theory reduce ultimate dynamic range by a couple of decibels, but it's almost sure to remain undetectable in real-world listening: I heard no impact, even via headphones on our audibility fade-to-noise tests and barely-audible tones, let alone real program material. -D.K.
