The 9444A is a stout design and much better than the 9444B. It is rated 8 ohms in bridge mode (two 4 ohm channels) due to how much current it can move and cooling by heatsink at high power. If you overload the amplifier (any amplifier) and run it at low power levels, it will survive without any problems. However, try to run it at rated power levels and it will overheat and fail.