In my car a cap would fit better though =/ hmm

 

If you want to see what a second battery is going to do, hook a good set of jumper cables up to your buddy's car (with it turned off of course) and see if it helps or not.

 

My truck is a Diesel so it has 2 batteries out of the factory =]
I haven't hooked anything up in my car yet, but I might try that one day by hooking it to moms van

 

that is the best suggestion i have heard here in awhile!
i would never had thought to try connecting to another vehicle to test.

thnx for the idea!
im sure it will come in handy when i get the sub in..

 

Some great suggestions here folks. Dukk, thoroughly impressed by your improvisational skills. If I remember correct you had some suggestions on covering tweeters for me as well. I'll be doing another run of 0/1 for the negative. I'll hook it up with jumpers and see if it makes a difference. Just goes to show me how much I still have to learn, I thought the HO Alt would have been needed for sure. We'll see how it goes anyways and i'[ll post the results here afterwards.

 

for the average car enthusiast a cap is perfect, i used a 1 farad cap for 1200watts and it got rid of my dimming headlights, you could run a 2nd ground to the frame, also HO alternator would be a necessity for that much power...Watts=amps x volts

 

a capacitor has a quick rate of current discharge, and most "caps" dont have enough capacity to warrent their use. The dimming of lights is mainly because your battery voltage hasnt dropped enough to initiate charging from your alternator. As your battery voltage recovers from the pulsating draw from your stereo, your lights become brighter.
A cap discharges quickly when you play at high volume and demands to be recharged by your battery til its full so really your battery is under constant load meeting the demand of the cap....this causes voltage of the battery to drop and because it doesnt recover voltage, the alternator now begins the charging cycle.

Your alternator will charge for longer periods of time and eventually burn-out. The only real way to utilize caps in your audio install is to have enough capacity to not completely drain out within minutes of use with your stereo. to supply a 1000 watts of output, you will probaly need about 100 farads of capacity backed up by the vehicles battery.
That would be expensive and inefficient use of space, you would be better off adding a second battery with its slow output, but the combined capacity of 2 batterys would better control voltage drop, reducing dimming of headlights and relieving stress from the alternator by not having to charge constantly.

If were speaking of caps in an spl scenario, we want as much current possible upon demand for the duration of a "burp" yet without enough capacitance, our voltage drops too low causing potential damage to equipment. Some competitors use multicell capacitor banks aka "batcap" in our spl install, but rarely would we use them without additional acid type batterys for the perpose of maintaining stable voltage while providing gobbs of current to our amps.

 

That proves caps have their uses.... A capacitor does the same thing for the very amplifiers we are powering as it does for the charging system.... For smaller systems a second battery would be like killing a fly with a shotgun. It does the job beyond expectations, but isn't necessarily practical So those systems can better benefit from a small 1 or 2 Farad cap. In the case of the OP's car, a cap could suffice, but at the load he's presenting the charging system, a second battery is most definetly the better way to go. In competition, caps make sense, hence "batcaps". A cap doesn't need to be trained to quickly discharge and recharge in short bursts, it's built that way. That makes them more predictable. Predictability = reliability and repeatability, key in comps. An acid type battery is meant for (generally) a slow drain (we are talking in an electrical context here) compared to a cap designed to charge and discharge very quickly. How long does it take to recharge a discharged cap vs a discharged battery??? Seconds vs minutes. Food for thought...

 

Much if this is incorrect. I don't mean to single you out as it is also popular opinion - many people have said similar things on here. A capacitor does not empty like a water bottle and then demand refilling. It sits at the same voltage that your battery does. Also, a capacitor discharges and recharges virtually instantaneously. If you consider the way the PWM power supply on an amplifier operates, how a capacitor functions, and how they relate to the charging system, you will understand when a capacitor is useful and when it is not.

 

Well I managed to get a smokin deal on a 5 farad Stinger cap. Intention was to run it to see what, if any effect it would have on my system. My intention it still to run a 0/1 negative to the battery. I was pleasently surprised to see that the cap has prevented the majority of my dimming lights. Quick fix or band aid aside that is a good thing in my books. That being said my subs are 500w a piece and the gains are down. If I end up getting a couple Icons and adjust the gain higher the cap would have limited impact and I would have to be looking at second battery and/or HO alternator. However, in the meantime I atleast can utilize the potential of my subs.

On another note, I took DUKK'S advise about jumper cables. It had no/very little impact. Which definetely leads me to believe the HO alternator would be a better solution.