I agree with dubber02, ditch the capacitor.
Also, unless you have passengers in the back of the car all the time and are willing to spend extra money on them, I would recommend that you do NOT use rear speakers. A decent set of front component speakers is normally adequate.
I have never had any complaints from rear passengers when I've only used front end speakers.
From my experience, rear speakers tend to do drag the sound to the back of the car. Use the money to fund an even better set of speakers upfront. What you want depends on what your budget is and what type of music you listen to.
I hope I've helped.
Last edited by Sonic Boom : 04-10-2012 at 02:01 PM.