i may word this wrong, but, im wondering and wanted to test this, say i have an amp that is rated at 1000 watts rms ok, this is all in theory and im wondering to test it with my jbl1200.1, ok well, the amp is 1000 watts rms allright, it has 3 30 fuses ok, well is there a way i can restrict its power, say i make it 2 30's and a 25 fuse, and make the amps then rms like 950 watts rms, or like 3 20's and make it like 700 watts rms, is this possible, is there a way to test it, a graph representing on what to do, anything?
Subfanatic, you can't restrict an amp's power like that to limit it's output power. That won't do anything but blow the fuses. Besides, you have to replace the fuses with SAME size. If you really want to put a limit on the output power, try with the input signal. You could put a limiter there so that the amp never gets it's required voltage. For example, if you set the gain to 4v, and you supply 2v, then it'll never give you 1000w.
I would try using a resistor to limit the output rca voltage. Measure the HU's output voltage first. Then using mathematical formula, find the resistor ohms required to drop the voltage to the desired value. You can also try using a variable resistor.
here's the simple answer: that amp puts out 1200 watts or so at peak output with a resistive, non-inductive load, and a signal generator. you're never going to run the system at that high of an output, so you're never really going to give the sub an actual 1200 watts. remember every time you audibly perceive the volume doubling, you're using four to ten times the power to achieve that audible increase. that means as you reduce the volume of the system, you're reducing the actual power the amp is putting to the sub substantially.
if you want to attenuate the output to the sub, the way to do it is by using an electronic crossover that has a level adjustment on it, or by using the sub-out level setting on the head unit that controls your sub amp. set the amp gain properly. remember that gain adjustment as NO effect on the amount of power the amp puts out. turning down the gain only means the amplifier has to use the same amount of power to amplifier a weaker signal, so you actually use more power to achieve the saem volume level. turning the amp gain up just causes the amplifier to clip, which will destroy your subs.