Does the underdrive pulley help out with the electrical systems? Or take stress off the alternater/battery?

I ask because I have 2 rockford 10inch He's subs and a pionner 760watt amp and a light is also hooked up to that power. Anyways I fried a alternater so I thought a cap would help, got one and fried another alternater. So I took out the sound system. But then that altenater went bad. So now im on my 4th one.

please help....

Will my Maxima ever injoy deep, loud bass ?

Will I be safe with a smaller Amp ?
Can it be a bad connection ?
Will the UDP help ?