So let's assume that OP uses Ohm's law to calculate what voltage it should take for that amp to make the "rated" 2000W into his nominal impedance. Then what? Which method do you think would blow it up faster, backing off a click of the volume knob when it starts to audibly distort or trying to turn up the gain until he sees 45V?
Naught for nothing, but if your amp is on fire you don't know everything, and if you don't really know what you're looking for, you should probably avoid "deals" on electronics to avoid problems like this. There's 100 junk brands out there. As people catch on to poor quality and untruthful claims these companies simply slap a different brand name on things, change the heatsink and fool a new round of suckers who believe that they're going to get something for nothing.
Best to verify that the gound is firmly connected to the amp, the terminals are well secured, and you have selected a good spot on the frame of the vehicle and sanded it down shiny to connect the other end. If you have verified your ground is good there's a problem with your amp.
