Sounds like you either have the gain or bass boost turned up too high, kicking it into protect mode. Or you have it wired incorrectly.
Are the subwoofers dual voice coils, 2ohm per coil? How do you have them wired? How are they connected to the amp? Where is the gain and bass boost on the amp set? Is there a bass boost on your headunit? Where is that set to? What is the specific model number of the amplifier?
I can tell u now that sony amp an't 1 ohm stable unless they just released something new yesterday thats 10 times better than anything they have out right now LOL....