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 -1.5.
Denon's AVR-4308CI impressed, with very good power results, and virtually perfect noise and linearity performance. Power with stereo channels driven handily bettered Denon's 140 watts spec, and performance with 5 channels driven was only a scant half-dB shy of that mark, at 126 watts.
Meridian's G95 measured excellently in every test. Power was just about spot on its 100-watt spec, though the unit fell a bare 0.8 dB short of this level with all 5 channels driven. True to its high-efficiency Class D nature, the G95 remained at virtually the same temperature (warm, but not hot) whether it was left idling all day, or driven to the verge of clipping for long periods.
As seems usual for Onkyo, the TX-SR605 showed just how technically accomplished mass-produced electronics can be today, with perfectly flat frequency response and perfect D/A linearity to -90 dB (and beyond). Both are as good results as I've measured, and while my memory isn't infallible, I believe this to be the first time these two particular aces have been drawn by the same unit.
The Onkyo TX-SR804's overall performance was fairly typical of mid-range receivers today, which is to say astonishingly good in most respects: Noise, distortion, and frequency response were generally very good.
I've come to expect stellar bench results from high-echelon Onkyos (and lower-echelon ones, too, usually), and I got them. Noise and distortion measurements were uniformly state of the art. Frequency response was excellent as well, though the TX-SR875 exhibited a very small rolloff, of about 0.5 dB per octave, above about 10 kHz in all playback modes.
Pioneer's latest A/V receiver produced uniformly excellent bench results: linearity and S/N were close to perfect on both PCM and Dolby Digital signals, while distortion and frequency response were nearly as good (the latter, in particular, on 96/24 PCM).