Should I add the Capacitor?

[rusty959]

Some of the responses in this thread I just LOL. Don't use the cap, it is a waste. Cap only work if you can maintain voltage. Once you start to drop what voltage do you think the cap is at? If you aren't dropping voltage with a cap, you won't be without it either.

This is starting to be the correct answer. The reason so many people bash the cap is because they misinterpret its purpose.

A capacitor keeps voltage continuous. What that means is the voltage across it can't change instantly. (hopefully no one tries to say anything against what I just said... its in the formula for a capacitor)

That being said if the capacitor is small enough it may still appear non-continuous. Get a large enough capacitor and you will start to see the difference. Where will you see this difference? Definitely not in long bass lines... the capacitor has plenty of time to discharge. This is where you need something like a battery/more powerful alternator. Quick bass hits? Sure, you might notice the voltage not dropping as low. You may have heard the term "stiffening capacitor" before. Precisely.

Here is another place it can help. Power is a form of average across time. If an amp wanted to (hopefully it never would to this degree) it could try to draw say, 1000 amps for 10 ms and no current for 90 ms. If it did this it would average 100 amps across time. 100 amps may not be so bad but you are pretty much definitely going to get some voltage drop from 1000 amps. While a normal battery/alternator system couldn't deliver this 1000 amp load a capacitor could. Maybe not for long, but 10 ms shouldn't be a problem assuming it is large enough capacity. Then it can charge up during the other 90 ms.

As stated hopefully no amp would ever do this. To this degree. That being said the load doesn't have to be constant. It can fluctuate a bit. Not going to lie I am not sure exactly how much it can.... I need to get out the oscilloscope and do some testing. But, say you are playing a 40 hz note at decent power. There is a good chance the amp could be fluctuating how much power it is drawing 40 times a second depending on how it is built and a capacitor would "stiffen" up the voltage supply. Again, I should get out and do some testing. Would be a good time.

Moral of the story. You probably won't notice a difference if you put it in. But, it shouldn't hurt anything. Ive never understood how people get the idea a capacitor causes the alternator to have more load. Someone feel free to explain it to me.

[AMI CUSTOMS]

If you don't have drop then the cap won't hurt a thing, but if you do have voltage drop and add a cap thinking it will help, all I can say to that is LOL, not gonna happen. If you drop below the set point of the voltage regulator hot or cold, the alt starts to increase output, a caps efficiency is based on what? Voltage. So if your voltage drop and discharges the cap, is more of the current not going into the cap to charge it instead of the amp? Yes it is. So what is the point of running a cap, to flatten out ripple that is it for a DC environment. Get a bigger alt and battery if you got voltage problems, not a cap.