Test Report: Anthem MRX 700 A/V Receiver Page 4
I loved almost everything about Anthem’s maiden AVR effort: its audio, its video, its outstanding usability. But $2,000, or even $1,500, will buy several other excellent-performing and more heavily equipped A/V receivers. They may not have Anthem’s high-end-A/V pedigree, or be designed in North America, but one or two may well look and sound just about as good. But it’s more than likely that many who encounter the new Anthems will also fall in love with their just-different-enough Canadian approach. See? It can indeed be done.
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 -10. All level trims at 0; 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: 147/216 W (21.7/23.3 dBW)
5 channels driven (8 ohms): 94 W (19.7 dBW)
7 channels driven (8 ohms): 71 W (18.5 dBW)
Distortion at 1 watt (THD+N, 1 kHz)
8/4 ohms: 0.02/0.04%
Noise level (A-wtd): –75.8 dB
Excess noise (with sine tone)
16-bit (EN16): 0.7 dB
Frequency response: 20 Hz to 20 kHz +0, –0.1 dB
STEREO PERFORMANCE, ANALOG 1 (stereo) INPUT
Reference input and output level is 200 mV; volume setting for reference output level was -10.
Distortion (THD+N, 1 kHz, 8 ohms): 0.03%
Noise level (A-wtd): –84.0
Frequency response: < 10 Hz to 21 kHz +0, –0.1 dB
STEREO PERFORMANCE, DIGITAL INPUT
Reference level is –20 dBFS; all level trims at zero. Volume setting for reference level was -10.
Output at clipping (1 kHz, 8/4 ohms, both channels driven): 137/182 W (20.4 /22.6 dBW)
Distortion at reference level: 0.02%
Linearity error (at –90 dBFS): -6.1 dB (see notes)
Noise level (A-wtd): –77.6 dB (see notes)
with 96-kHz/24-bit signals: –84.5 dB
Excess noise (with/without sine tone)
16-bit (EN16): 0.5/0.2 dB
quasi-20-bit (EN20): 13.0/12.9 dB
Noise modulation: See notes
Frequency response: < 10 Hz to 20 kHz +0, –0.05 dB
with 96-kHz/24-bit signals: See notes
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 84 Hz
High-pass-filter frequency response (crossover set to 80 Hz): 12 dB/octave below –3-dB rolloff point of 89 Hz
Maximum unclipped subwoofer output (trim at 0): 7.8v
Subwoofer distortion (from 6-channel, 30-Hz, 0-dBFS signal; subwoofer trim set to 0): 0.02%
Crossover consistency: bass-crossover frequency and slope were consistent for all sources and formats.
Speaker-size selection: all channels can be set to “small”
Speaker-distance compensation: available for all main channels
The Anthem MRX 700 evidenced a couple of head-scratchers on the test bench, but its performance was otherwise exemplary. Frequency response from all digital sources save one was essentially perfect, and distortion was consistently very low. Power delivery was generous: The MRX 700 very nearly doubled output into 4-ohm loads (in stereo mode), which is rare for a receiver, and also delivered a very healthy 94 watts with five channels driven simultaneously, which is far above average.
The oddities encompassed our unique tests of digital-to-analog linearity and “noise modulation,” which examine D/A behavior at exceedingly low signal levels, and an oddity of 96-kHz/24-bit playback. Taking the latter first: On a stereo 96/24 frequency-response sweep, the Anthem’s output remained perfectly flat to roughly 5 kHz, beyond which point it rolled off at about 2 dB per octave, reaching -6 dB at 32 kHz, where output essentially disappeared. I’m completely at a loss to explain this anomaly. Returning to the low-level stuff, the MRX’s D/A linearity showed virtually perfect response to signal levels as low as -80 dB (re: 0 dB full-scale), but was 6 dB negative (too small) at -90 and unlockable at -100, which suggests a least-significant-bit flaw, or a math error at some point in the conversion or resampling processes. S/N on both PCM and Dolby Digital signals also measured about a decibel “too quiet,” which tends to support this idea. On the same track, our “noise mod” test, which requires the converters to track a midfrequency tone that repeatedly sweeps amplitude between “very low” and “very, very, very low” signal levels, failed to execute fully since the receiver would not resolve the 251-Hz tone over its full level sweep, which extends well below -100 dBFS. Noise mod results above that point looked fairly good, though obviously incomplete. — DK