Ok I am going to go into the best detail I can here..
I am running 2 Sony Xplode 12" subs, a 1000w amp running at about 800w RMS @ 2 ohms, and a 1 farad capacitor.
Now my problem is, with the capacitor hooked up I cant hardly turn up my system at all, the volts go way down and my amp shuts off, (I'm guessing due to lack of power) with out the capacitor on it works ok. I have a 125 amp alternator and this is all in a 95 Chevy s10 ext cab. Now my question in, is my capacitor fired? Did I buy a 100$ voltage meter? Any help will be greatly appreciated!
There's a chance that your cap could be dead (highly unlikely). What you can do is test the cap for shorts. If it has a built in volt meter, then disconnect it. Mine had it but it came damaged. Try the cap by itself. Use a DMM and see if it has a short or if it could sustain a charge. Check to see that you didn't accidently reverse the polarity.
I figured out the problem, the wire that came in the kit (4ga. batterie cable) was bad, I tested it after testing everything else and replaced it with aother one i had laying around, it works fine now. I did notice that the subs hit harder with the 8ga. wire I was running though, any clues on why that is?
What you posted about 8ga vs 4ga doesn't make any sense. Not possible in electronics. Perhaps maybe the 8ga has better contact with the battery/ground over 4ga, thus yielding more current.
Just leave the cap off if it works better without it. Capacitors do absolutely nothing to help your charging system anyway, so yes I guess you could say it's a $100 voltmeter, lol.
Could be, but try this. Think of 8ga as 1" pipe, 4ga as 2" pipe. Now if you had those pipes going into your shower, which do you think will give you more water/pressure?
Just leave the cap off if it works better without it. Capacitors do absolutely nothing to help your charging system anyway, so yes I guess you could say it's a $100 voltmeter, lol.
This is true but a power cap CAN serve a purpose. If its equivalent resistance is sufficiently low and the cap is located close to the amp(s) it can help out transients where amplifiers have suddenly high current demands. However, in practical use most caps don't have a low enough Req to provide much help.
Using Isaac's pipe analogy imagine a ficticious city's water system where (in this case)a water tower(the cap) with a limited volume(capacitance) at a good height overhead is utilized to provide water pressure(voltage) and instant volumetric flow(current, funny how thats like a river huh). A good size pump(alternator) is used to fill the water tower. Well one day all of the sudden everyone in town flushes their toilets(massive kick drum hit). A pump alone would have a very hard time keeping up with the sudden loss of water pressure(voltage drop), but thank God for that water tower. It manages to adequately provide a lot of water(current demand) in a short period of time.
In reality most caps can be compared to a water tower with a very small outlet pipe(high equivalent resistance) and do little good, but theoretically there is a cap out there somewhere that will help things along in a car audio system.
-Fishy
P.S. Water pipes aren't really the perfect analogy. A short section of pipe doesn't really model a short section of thin wire well. If that were the case fuses would absolutely kill current. A better comparison would be "necks" in a pipe and the actual resitance of a complete run of wire.
Oh and continuing the analogy Power, P=I*V, is represented by volumetric flow times pressure. This in fact is actually how power in a water system is determined. Pretty neat huh?
Most won't fall asleep, they will start drooling and walk away cause they didn't understand a word you said. But that did help me, after figuring everything out everything works fine with the cap. I know I need a bigger alternator now after going trough some stuff, which kind of surprised me being it is a 125amp alternator. But it will help in the long run since I will be running 2 JL 12w7v2's and 1 or 2 1000/1 JL amps, unless I can find a better amp for a decent price.
Oh and to put things into perspective. I've been designing a system for my "new" Explorer. I've got 3 Audison amps, a Clarion DRZ-9255, a set of SEAS Refernce Lotus components, and a JL Audio stealth box sittin in my room waiting to be installed. There's an awful lot of money layin there, and the funny thing is I don't see a single power cap, hehe.
I wouldn't waste my time or money on one, at least not any that are readily available to us consumers. Good amps with really good power supplies have very low ESR(equivalent series resistance) capacitor banks built in. I'm not an amp expert, and I believe their operation is a bit different, but basically a good amp should be able to handle those transients no problem as long as there's a decent alternator powering them.
