Although I have a 7100, I've driven the 7 channels into a combination of 4 (and maybe lower) and 8 ohm, inefficient speakers without any problems, and with the unit getting only moderately warm. Luckily, I now have a 7.1 system with newer, more efficient 8 ohm speakers, and after several hours of listening to music and/or movies, it barely gets warm. With its added power, I'm sure the 7125 will perform even better.