what size / brand capacitor?

[Dave Ladely]

capacitors?

Caps do NOT let current "burn" better! Does not even make sense! Current does "burn" in any sense.
And Autobahnsho implies that the distance has something to do with how quick the current gets to your amps, mentioning that resistance is the culprit. Nonsense. As is his arbitrary estimates of how big an amp an alternator of such and such power can output. especially using the max power claims of the amplifiers.

1) Electrons flow at the spead of light and the speed of light is a constant. So a cap will NOT "speed" up current, and resistance does not slow current down, that is impossible! Check it out with a physics book.
Resistance causes voltage drop. It also causes the wire to heat up due to friction of the current. You dont want much of a voltage drop and you dont want the wires to get hot. Those are the reasons for justifying at least reasonably heavy wire, beyond reasonable, however is the American way!
2) the max power of amps is almost always highly overstated for marketing to ignorant customers. RMS is the only honest power rating whatever the hype.
To take the max RMS rating as the criteria for the minimum or desired alternator output is unrealistic in the extreme. The max RMS rating is rarely approached with music, and high RMS wattages are of very short duration. The average power consumed over time by the amp even when being played loud, is a lot less than one expects. The average wattage over, say 15 minutes or an hour is unlikely to be over 100 rms watts continuous over that period. At about 14 volts, that is around 7 watts RMS! When my stereo is running hard, my marine digital ammeter, which measures amps over about a second, so it does not measure millisecond peaks, rarely goes above 10 amps over short times, a matter of seconds. That is not much of a strain on my alternator. My starter battery shows an average of about 21 amps with all my lights on, including my Catz driving lights. So, the combination average amperage consumed over a period of minutes at a time is only about 31 amps when everything is really going hot. My batteries have never lost charge while I was driving. If I was to sit at idle for an hour or so, then I would expect some discharge as my alternator output at idle is about 28 amps, causing me to drain the battery at about 3 amps, assuming I had all my lights on and my stereo blasting. Having a deep discharge battery, with a marine type isolator in the trunk has allowed complete isolation of my stereo from my lights, etc., and so there is no dimming of lights, no shutting off of my stereo.
Those who think resistance slows current and that capacitors speed it up need to do some studying. Capacitors are useful in electronic circuts to filter ripple, etc, but huge capacitors in the power line are being misled and using the common "big is better" philosophy. Its predictable that people who are ignorant of technical matters are vulnerable to sales pitches which distort meanings and which ecourage the customer to buy something neither they nor even the salesperson eally understands. ****, most people are ignorant of the 3db power requirement increase problem!
Those who shink that an amp's max output rating is a continuous consumption at even max volume also need to study and reflect.

 

[autobahnsho]

And Autobahnsho implies that the distance has something to do with how quick the current gets to your amps, mentioning that resistance is the culprit. Nonsense. As is his arbitrary estimates of how big an amp an alternator of such and such power can output. especially using the max power claims of the amplifiers.

Sorry, I didn't think I implied that.
I did quote the stereo installer "do it yourself" for newbies from Crutchfield.com guide. I didn't say it was all correct, but most if it made sense to me.

I know that no matter how long your cable is, if the resistance is low, if you push one electron on one end, the other end pushes one out almost instantenously. (Speed of light.)

So all that light switch flicking on/off when I was a kid to see how long it took the light to come on after I flipped ths switch was in vain...

 

[Dave Ladely]

capacitor

Yes, electrons "bump" from one end to the other, another theory is that "holes", that is to say, the positive charges, can be considered to go the opposite direction, so, depending on which one, "flow" can be considered to go either way!
Kinda fun to read a good physics book about the nature of electronic behavior at the deepest level. Gives a person a foundation of knowledge which can help a person gain insight into what science is behind choosing solutions to problems rather than relying on marketing misinformation motivated by money and, that hidden motive, ego, especially male ego. Embarrassing when women make choices based on logic rather than ego, and might not be moved much by the capacitor sales pitch, especially when they are supposedly the ones who base decisions more on emotion. Ego is an emotion! Eh???
May not be glamorous to use something basic like a second battery, deep discharge type, with a marine isolator and maybe even have an alternator rebuilt for higher output instead of getting a multi farad flashy goodie with gold plating and a hot logo pumped by hip advertising, but one is closer to attacking the source of the problem rather than trying to justify adding a goo-gaw of minimal advantage for maximum cash. :****:

 

[Shoaz]

Caps do NOT let current "burn" better! Does not even make sense! Current does "burn" in any sense.
And Autobahnsho implies that the distance has something to do with how quick the current gets to your amps, mentioning that resistance is the culprit. Nonsense.

Distance to the power supply has a LOT to do with the effectiveness of a storage or bypass cap at a local device. The resistance of the cable does have an effect on the voltage drop and amount of loss due to the cable, but more importantly all cables/wires/circuit board traces also have some inductance associated with them. That inductance limits how fast the current flow can change rate. i.e., the system cannot go instantaneously from supplying 5amps to 10amps, it takes it a while to ramp up depending on the amount of inductance and capacitance in the system. If the local device (e.g., an amp) wants to draw current more quickly than that then it will suffer from whatever starvation effects will ensue. A local cap supplies the difference until the power supply can catch up. This won't work unless the cap is between the inductive element (in this case the supply cable) and the load device that is making the current demand.

1) Electrons flow at the spead of light and the speed of light is a constant. So a cap will NOT "speed" up current, and resistance does not slow current down, that is impossible! Check it out with a physics book.
Resistance causes voltage drop. It also causes the wire to heat up due to friction of the current.

Friction? Electrons have friction?

I think you'd be surprised at how fast electrons actually move in a typical system. They don't move at the speed of light, it'd be tough for them to do that since they have a measurable amount of mass. The effect of the electrical force can move at the speed of light, but the electrons can actually be pretty slow. A physics professor in college had us calculate the amount of time that it would take a single electron to get from the light switch to the overhead flourescent lamps in our classroom, given 110VAC, estimated length of the wires, estimated current draw for a typical set of lamps, etc. It was hours, and it was not a trivial calculation.

Those who think resistance slows current and that capacitors speed it up need to do some studying.

I'd offer two points here: First, I don't recall anyone here saying that resistance slows current and capacitors speed it up. Second, it's clear to me that your understanding of this stuff is more limited than your posts would imply. You might want to be careful who you say needs education.