Hey my friend has 2 audiobahn 1206ts in a sealed box powered by 2 a8000ts and he had his system on today and the cones on his subs were gettin hot, does anybody know why?
well they're going to get warm.. remember you're still dissipating a lot of power across those coils, even with a clean sinewave signal. That's why speakers have thermal ratings telling you how much heat, in watts, they can handle without melting. this is also why the motors are vented, to aid in cooling the coils.
remember also that only about 5% of the energy put out by the amplifier into the speaker actually results in acoustic work (sound) you lose 95% of the actual power to the inefficiency of how speakers work.