David@FrankHarvey said:
Feed it a digital signal and you find out how good it's DACs are. Feed it an analogue signal and you find out how well it isolates it from all the unnecessary circuitry. Use a number of differently capable speakers and you find its limits (although what it can drive well in two channel mode isn't necessarily the same as what it can when all channels are driven).
I know my AVR is way down the pecking order compared to those in this group test, but I know my AVR's biggest failing is its analogue inputs. I think its DAC is surprisingly good, but when I fed my AVR using the analogue RCA outs from my CD, the difference was palpable. But feed my amp a good Bluray (audio only or a movie) and it can sound spectacularly good considering its original RRP.
My earlier point about which speaker packages used was mainly about synergy, and that sometimes an amp/speaker combo can sound greater than the sum of its individual parts just because they both play so well to each other's strengths; so saying that one AVR's sound quality is 'better' than another might just be because the amp/speaker synergy choice is poor.
Of course, with an AV receiver able to power so many speakers these days, a group test of this nature, including plugging and unplugging speakers and the set-up procedure can take many hours, so I appreciate doing a group test like this with multiple packages could be much harder (or practically impossible) than an equivalent 2-channel test. Still, if we knew what speakers were used, it would help.