I had been using the speakers as a part of a 5.1 HT package apart from stereo listening..I wonder if I overdrove the amp when doing so, as the 803 d3s need 8 ohms. The pair of surround 607s also need 8 ohms as does the centre speaker..perhaps it overheated?I have read people driving the new B&W D3 speakers with lesser receivers to party levels without issues on US forum. That AVR850 is still Arcams flagship model (Class G amp) so i would be intrested what type of volume levels he has used. This receiver is quite powerfull if comparing to others. In German review it benched 7channels continuosly 4ohm load 134w so it should have decent power supply.
2 channels driven, 20Hz - 20kHz, <0.02% THD - 120W (8ohm)/ 200W (4ohm)