Capacitor? Is It Usless>>?

[Boon]

40F+ of capacitor is kinda useful, it can help keep the voltage at the amp terminals high for a moment longer.

1F is only useful as a ripple filter attached to your headunit...

[wildbeast15]

i use a 2 caps and they help a little to keep the voltage constant...

[Sable Nave]

Caps are good when used properly, not a solution for a bigger problem

[tacomabanga1986]

caps work just like a smaller battery if u CHARGE em first, i ran a mtx 500d @ 1ohm with 2 mtx 4500 1544's at full tilt my voltage was 14.6 so ya it works a hell of alot, just not for alot of power, a cap will work with up to 1000w, but i wouldn't use one over 600rms really, i ran a cap in my truck for about a year n switched to a battery and workes better, but a battery takes longer to charge, and will not dispurse as fast as a cap will, my voltage would drop from 12.0 to 11.5 with car off but would jump right back up perfect to 12.0 again, caps help in smaller systems to keep up current flow better, but when u go from 1500+watts rms a secondary battery comes into play to help out for the amp draw, so in ur case ied just run maby 2 extra battery sence u got 4 1000w amps

[neuspeedescort]

caps are commonly used as bandaids to larger issues. granted they have there place in the game but no used as often as they should be.i have not ran a cap in 8 years. the last couple i used where batcap400's they are a nice hybrid setup.

NEUMAN

[Rags2Bitches]

you might as well be running you power wire into a big smelly fudge dragon. It accomplishes just the same with that kind of voltage drop.

I've always been told performance batts (such as a yellowtop) is the equivalent to a 100 farad cap. Whether that's true or not, I'm not sure, but it sounds not too far off from the truth judging from past experience.

[finkster]

didnt snafu school everyone last year on this topic? its a sticky in the RF section...

Heres what he put....

Holy Cow there's a bunch of mis-information in this thread about caps. Caps work - period. But how? Simple . . . capacitors do TWO things:

1. Store charge

2. Oppose changes in voltage

Now, both of those things sound mighty nice to me. To understand how a cap benefits a car audio system, one has to first understand that there are TWO separate voltage plateaus available in an automobile:

1. Running - With the alternator charging, voltages will typically be from 13.8 to 14.4 VDC

2. Not running - With the alternator IDLE, voltages will typically be from 12.0 to 12.6 VDC

I'll take the higher of the two any day. For UNREGULATED amps, this allows them to draw MORE current therby making more power. For REGULATED amps, this allows them to draw LESS current to make their rated power. Either way, it's a WIN for you. So, how do we ensure the higher of the two?

Again, simple. With the vehicle running, consider the DELTA between what the alternator can make and what the nominal voltage the batteries can provide is. For this example, lets assume 14.4 VDC - 12.6 VDC = 1.8 VDC. When we exceed the current output capability of the alternator, it's voltage output is compromised. In some cases, heavy demands of amplifiers can far exceed the current capability of the alternator, leaving us with only the reserve of current within the battery. But, car batteries weren't intended to power amplifiers . . . they were intended to start cars [battery = Load with vehicle running.] A really fresh car battery can do this for a while, but given that we're exceeding the output capability of the alternator, it's charge isn't getting replenished quickly enough - need about 13.0 VDC minimum to allow charge to flow back into the battery.

A properly sized capacitor will change the rules. With the vehicle running, it stores charge at the higher voltage plateau - 14.4 Volts. As the amplifiers demand current, it will flow from the place of least resistance . . . Ohm's Law tells us that happens to be the place with the highest voltage. That will be in order:

1. The capacitor (closest)

2. The alternator

3. The battery

Ideally, you've selected the correct size capacitor for your system's needs. And . . . that "30F" cap that sells for $59 in a blue velvet box with chrome and a big blue LED readout is just a glorified volt meter These devices have ZERO benefit. There is a reason why quality capacitors cost money, and ours are no exception. These are the facts:

1. A 1 Farad capacitor can store and release 72 Joules (watt*second) of energy at 12 Volts.

2. Said capacitor can charge and discharge hundreds of times faster than an automitive battery of any kind.

3. Capacitors present nearly no load to a properly set up charging system.

4. Automotive batteries require 7 to 10 amps of current EACH to allow charge to flow into them.

5. Capacitors work GREAT for every day street systems.

6. The benefits or capacitors are negated in SPL competitions.

For best results, I recommend locating capacitors within a foot of the amplifier - as in, no more than 12 inches of wire between the capacitor and the amplifier. The further away from the amp they are, the less of a benefit they offer.

I have used them my systems for a very long time . . . since about 1986.

Edited March 8, 2009 by finkster

[Sable Nave]

One Farad per 1kw

[Kicker Guy]

^^haha thats funny. caps have their place just like anything else. they have to be used right. do you thing rockford fosgate would make a completely usless product? even steve ran or maye still is running a pair of 40 farads in his civic. it honestly depends onwhat your trying to get outta your system

Yes, all company's do.... thats how they make money.

[ISO]

Shit Snafu's post didn't sway me one way or another on the capacitor issue.

It was the almost brand new 50 farad CPCC1 hybrid capacitor that I got off of Ebay for $75.00 because the guy didn't know how to label his auction propperly and no one else really saw it. After I got it I found out that MSRP was like $650 so maybe around $500 retail.

I used it for about a year before Snafu put that up and like alot of people on here I hated caps too untill I learned how and why to use them.

Now I'm upseat because I'm not going to beable to fit that big bastard into my next install.