digital capacitor

yes that is what it is for, to wire multiple amps. u say its a 3 farad cap. u figure u need only 1 farad per 1000 watts

im not sure but i think that model is a 2 farad cap but your still ok, alot of people dont like caps but personally i think there good for smaller systems, y would these big companys sell them if they didnt have some positive effect in a system, also look into upgrading the big 3

"y would these big companys sell them if they didnt have some positive effect in a system" They are an easy sell with a huge markup. Marketing!

first let me point out that i said they are good for SMALL SYSTEMS. they do have a positive affect with eliminating alt whine,engine noise, and headlight dimming. i definitly wouldnt use it when building spl system, however sure its no different than saying that your car needs zmax or duralube but it doesnt hurt to, yeah the affects are minimal but they do have positive affects.i guess what i was trying to say is that they are not selling something thats gonna hurt or damage your sytem (if installed propery).

Capacitors are a huge hot-button topic and it's largely the industries fault (marketing, bottom line, etc.) A long time ago some smart guys decided that using a giant capacitor would help filter the input to an amp and help keep the supply voltage at a constant 14.2 volts or whatever their alternator were putting out. Just because an alt can put out a lot of current, doesn't mean it can react quickly enough to keep an amp happy. These smarter guys also learned that you need the capacitor to not only be big, but to also discharge and charge quickly enough so that it can indeed supply the amp with the voltage when it needs it (I.E. cap can't be as slow or slower than the alternator, or what's the point in having it?). Manufactures noted that this was another object they could create hype about and sell to everyone they could bamboosle into thinking they needed. So people with no knowledge of how they function wrote marketing crap to sell them to other people who have no knowledge of how they function (most customers). Couple that with dishonest or naive sales staff throughout the world and you have a slew of misconception and misapplication propagating ridiculous claims that don't pan out. Cap facts: Capacitors can only store and discharge energy. They cannot create energy and due to the laws of entropy, will actually waste some energy in doing what they do. A capacitor must have a very low ESR or it will not do any good and only serve to separate you from your money. Additionally the wiring between the capacitor and your amp should be as short as possible and very low resistance or again, it's going to be pointless. I've seen installs where the cap is in the engine compartment by the battery and the amp is in the trunk and that is essentially pointless. I don't know of the technology used by these newer 3, 20, and 40 farad caps, but honestly I doubt unless some miracle, alien reverse-engineering type technology I don't know about has replaced conventional electrolytes, that these monster caps will discharge fast enough to do any good. 8 years ago that technology did not exist, I know for fact. Getting big Faraday numbers is easy, getting a cap to charge and discharge quickly at them is not. Those digital deals on top of the cap? Marketing department! Who honestly cares what the voltage is at that point? If the read out switched at the speed of the actual voltage fluctuation, you wouldn't be able to read it. To keep the readout steady, they use a resistor. Sometimes these devices increase the ESR of the capacitor (typically .002ohms or less in a quality unit) to the point where it does no good (like .25 ohms or more in a cheapie unit). If you're truly buying the cap to use it (rather than for show), the digital read out should be avoided. Back in the mid nineties I knew a guy who cut apart capacitors and most were only half or 3/4 full of foil (stinger was one of the worst). There are also different types of foil and as already mentioned, electrolyte as well. All this affects the ESR and actual capacitance of the unit. Since the machine necessary to test the capacitance of even a one farad cap will cost thousands of dollars, manufactures know they can sell you about anything and you'll be forced to believe them. Most failed cap installs are the result of either a bad install (too much resistance between the amp and capacitor) or a "cheap" capacitor (too high an ESR to begin with). In either case the addition of a capacitor will do nothing to help the system. Also, caps should not be relied upon to replace an alternator! If your alt puts out 50 amps and your system draws 60, the cap ain't gonna do you any good! A capacitor is a supply voltage filter, it will smooth the incoming voltage level at the amp and that's all it can do (if the above criteria are met so that it actually can) do that. A capacitor will not place a substantial increased load on your alternator because it is not the item drawing it down in the first place. The exception is the mention of entropy above, I don't know how much energy a cap wastes, but if it's a super-low ESR unit (and it had better be) then it can't be enough to hardly measure, more or less worry about. Too much capacitance won't hurt, but is pointless.