Last year I had the living room converted. Now, a surround sound system and a matching LED TV was needed! Of course, all with no visible cables. In conjunction with the AVR Denon X2000 I am then at Nubert speakers (postman already knew my name :-)) stuck. Setting: nuVero 3 Front, nuVero 7 Center, Nuline 32 Rear, 2x Nuline AW 500 Sub .. The X2000 played well so far on when was fine-tuned manually after calibration Audyssey. However, I always had the problem that the X2000 very very hot was, whether loud or soft. If I have the time turned up properly, the X2000 is turned off (protection circuit). My guess was the 4OHM speaker of Nubert. As is known, brings an amplifier yes more wattage at 4ohms. Well ... Here the decision to buy the X4100: Can be switched to 4 OHM, Audyssey XT32, second SUB connector with separate calibration SUB EQ HT. First impression: Switching to 4OHM, just Handwarm (5hrs.) :-)))! Calibration XT32 audibly better! All speakers are much better integrated. Subeinmessung super ... no roar, nice draft in the little things! In the X 2000, I had to readjust! For now strong buy recommendation!