I recently tried Marantz and Denon receivers both rated for 80w per channel with MS Avant speakers. Marantz sounds great at the volume of -10, but Denon has to struggle at the volume of 00 to produce the same loudness, also suffers lack of detail and loosing weight. So why those receivers with the same wattage don't have same loudness ability? Denon AVR-1905 & Marantz SR4500