Yeah i see your point but also if you listen with your speakers off then you will actually get more power cause the inpit voltage can vary without varying the output which can be nice. Form what ive read in testing (i know people are saying that is bias) but it pumped out 90 watts into a stright resistive load and will almost double its power when driving a reactive load like a speaker. That is just straight test numbers. In a reactive 4 ohm bridged load it put out 230 watts x 2. I think you would have to compair it to the arc 4050 and not the 4150.