Not good for much really. Most people that push them are either idiots, or salesmen. Caps help smooth out voltage rails, and stupply quick bursts of current when there is a very quick high demand, so the voltage doesn't dip. But if you don't have an adequate Alternator and other electrical components, then the caps only gonna hurt you more. Even if your charging system is up to par, you really don't need one.
capacitors don't help voltage rails. that's a gimmick. they never tell you capacitor voltage parallels circuit voltage, so if voltage drops due to a weak alternator, the cap voltage dips too.
a capacitor does work as a filtering device for AC ripple caused by the AC produced from the alternator not being smoothly rectified to DC voltage by the voltage regulator.
the reason there's such a widespread myth about capacitors is due to the lack of understanding about how they work. people equate acapacitor with a battery since capacitors store current, and release it quickly. a capacitor only works when the current supplied is equal to the demand of the circuit though. when the demands excede the supply, you have problems no capacitor will fix.
Glass, I know caps don't act like batteries. I wasn't talking about using a cap with a poor charging system. My point was that if your charging system is up to par, it mainly fills very small quick dips in current voltage. If your alternator is supplying enough power, but your amp hits a quick note that demands a fast burst of energy that the alt and battery cannot supply that quickly, the voltage will drop and the cap will discharge for only an instant.
glass--1 last question for future reference. w/ the kicker cvr12 4 ohms dual voice. If I were to put an amp with 300 x 1 vs 400 x 1 would you be able to distinguish te sound from the subs right away. Or it wouldn't sound that much different. thxs alot for all your help
maybe 1dB difference? not much. you'd get +3dB with twice the power.. double the audible volume is equal to an increase of +6 to +1-dB, or four to ten times the power.
it takes a lot of power increase to audibly affect the volume.
Posted by Glasswolf: "capacitors don't help voltage rails. that's a gimmick."
Taken directly from Glass's website: " A capacitor WILL: -Stiffen voltage rails. If you experience very brief, momentary periods of high current demand that cause the electrical system to falter only at these rare, peak draw times, then a capacitor will supply the additional current needed (when bass hits) to keep your voltage rails stiff, and prevent damage to the car or audio equipment."
Honestly, some things Glass has said just don't add up...
How can a cap not help smooth the voltage curve. That's pretty much it's sole purpose? To supply quick bursts of power which helps the sub's transient response.
I think what GlassWolf was trying to say was, a cap can help smooth out voltage spikes as long as the alternator can supply the needed voltage. If it can't, then the cap will be useless cause, once it loses the charge, nothing will be there to recharge it. I have HO alternator, but I still use my cap for tighter bass response and to filter power. Lot of people use the cap to replace HO alternator. That is where the false sense of security causes damage.
capacitors store cutrrent, but if the voltage rails sag, the voltage of the capacitor follows suit. IF the alternator is of sufficient size to keep the voltage rails where they belong, the capacitor will work to decrease propogation delay by supplying current more quickly than the alternator can. I need to revise the article on the site. it was written a few years ago and I have some things to add to that when I get motivated to do so. I just have other things to do.
Joe believe whatever you want about capacitors, but until you have an EE degree, or do a lot of studying up on how capacitors actually work, please don't assume things about them based on product advertising.
I don't assume things about them based on product advertising, I assume partially from things written by highly respected Electrical Engineers, . That's exactly what my point was though, they only help if you have the proper charging system.
I'm not trying to argue with you Glass, and if you correct me, then I'll gladly accept what you say. Sadly I'm not becoming an electrical engineer, and I'm not a master installer (although I'd like to be).
I've been meaning to rewrite that page for a long time which is one reason I haven't linked to it recently.
anyway, you need a big enough alternator no matter what for driving. if its for SPL events, and the car is shut off, you ned batteries to handle the demands. caps make nice filters though
. That's exactly what my point was though, they only help if you have the proper charging system.