The new Yamaha RX-V4600 willl drive any load without a problem. Some however have reported that the same can't be said about the RX-V1400, RX-V1500 and even the RX-V2500. Look for the review at Audioholics on the RX-V4600 as they talk about the power in the RX-V2500 when it comes to tougher loads.