The truth about caps

[talnlnky]

Originally Posted by Spades

but, the question would be, on a lower wattage system with a average cap where you were playing music with a consistent hit, that would require bursts of energy for the subs, would a cap be a bad idea? regardless of how it affects the alternator...because, the alternator WILL be taxed by lots of stereo goodies regardless of the alternator. i mean, you are still draining the battery.

i was under the impression all a cap was for was to reduce strain on your battery that causes headlights to dim as it sucks a large amount of amps with a quick bass note. a cap isnt meant to relive strain on the alternator, i thought it was meant to aliviate the battery.

technically, no matter how powerfull the alternator and the battery(batteries?) the alt is still going to have to charge the batteries at some point, you are still using the energy when you are pushing your amps to clipping...no matter how many caps you have, that alt will still be taxed.

i guess maybe i mis understood what manufacturers were claiming their caps could do. I always assumed that everyone understood a cap is for a faster harder hit of bass and would keep your battery alive longer and eliminate headlamp dimming. i guess i never heard of a company claiming their cap relived alternator strain.

A cap will help in a car that already has an alternator that can keep up, and still has a bit of headroom, along with a decent battery. HOWEVER, if there are any symptoms of an electrical system that can not keep up, then it will do more harm than anything else.

Symptoms could include, weird rpm fluctuations, dash or headlight dimming, slower than normal starts when you turn on your car.



There was another write up that was pretty good that I no longer find anymore, it showed the math behind the discharge of a cap... Basically It came down to a 1farad cap would only be able to power a 1000w amp for something like 1/10th of a second, and then its power is used up, and then becomes a drain on the system... That is where Richard Clark's article picks up. If a cap is being fully discharged, you've got bigger problems than a cap can fix.



To answer the question about headlight dimming... yeah, a cap will make it appear that your head lights don't dim as much. The reason for that is because your lights won't be getting as bright. They will stay dimmer, longer, and thus you won't see as big of a fluctuation, because there will be a constant drain on your electrical system.

[supmet]

Originally Posted by talnlnky

A cap will help in a car that already has an alternator that can keep up, and still has a bit of headroom, along with a decent battery. HOWEVER, if there are any symptoms of an electrical system that can not keep up, then it will do more harm than anything else.

Symptoms could include, weird rpm fluctuations, dash or headlight dimming, slower than normal starts when you turn on your car.

Well I've seen a cap PREVENT headlight dimming, and the only way it could account for slower starts is if you turn your car off in the middle of a bass hit(but if you care about your car you'd be turning your stereo off before turning the car off)

Originally Posted by talnlnky

and then becomes a drain on the system...

Please explain the mechanics of phantom energy to me. Where does this drained energy go? (besides resistance)

Finally, you should release these results to the thousands of stereo shops that recommend caps. Along with all those people winning stereo competitions. Oh the people making the caps will probably want to know too.

I think I'm gonna stick with the millions of articles that say caps work, rather than the ONE that says they don't.

[talnlnky]

Originally Posted by supmet

Well I've seen a cap PREVENT headlight dimming, and the only way it could account for slower starts is if you turn your car off in the middle of a bass hit(but if you care about your car you'd be turning your stereo off before turning the car off)




Please explain the mechanics of phantom energy to me. Where does this drained energy go? (besides resistance)

Finally, you should release these results to the thousands of stereo shops that recommend caps. Along with all those people winning stereo competitions. Oh the people making the caps will probably want to know too.

I think I'm gonna stick with the millions of articles that say caps work, rather than the ONE that says they don't.

I have yet to see a single SPL vehicle at world finals run any caps. They have crazy sponsorships that allow them to pick them up for cost. There is a reason why they don't run them.


All the non-believers can go to some actual car audio forums, elitecaraudio.com, and soundsolutionsaudio.com are two decent forums.

Car shops make money on them, they make all their money on accessories.. Decks and speakers bring them almost no profit, its connectors, caps, and wiring that they get their profit from. Why stop selling a product that pays the lease on your building?

there are also articles, RECENT ones that say likewise, Also, it takes NO education, not even a highschool diploma to open a audio shop, or to be the head installer. Try talking to an electrical engineer who has actually studied the science behind the problem, and is familiar with car electrical systems. If nothing else, adding a cap to the electrical system adds two more connection points which add resistance, and thats before you even add in the internal resistance of the cap itself. STORAGE MEANS NOTHING if the power plant can't keep up. Eventually the storage will run out. CAPS are storage... and a very small storage at that. Anything more than what is built into the amplifier is overkill, and will not help you at all unless you already have a power plant (alt) that can keep your storage (bat) 100% full 99.9% of the time already. If you fit that situation... then you won't have significant voltage drops at all, but you will still have very minor fluctuations (talking in the range of a tenth of a volt or less). In that situation... yes, a cap will help stabilize the voltage the way it is supposed to.

But, is +/-.05v worth $100 or more per farad? People who have light dimming are most likely seeing dips of 1.5v or more already, just for refrence.

For those who swear caps stopped their lights from dimming... did you have volt meters recording your voltage real time? Did you have light sensors watching the output of your lights... did you do A/B comparisons?

If not, then admit that your "real world experience" is very possibly incorrect, and flawed with bias.

I can't think of a better quote to describe this situation other than...

"We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology."
-Carl Sagan

[talnlnky]

Originally Posted by camelll

My thoughts exactly about you saying caps don't work.

The cap can only be charged to the max voltage of the alternator, so if your alternator is already strained then it can become an extra strain on the system. If you listen to music that is just one continuous bass note then yes a cap is no good. This is not the norm for end users. For a car audio competition then yes a cap would be useless, that is why they don't use them. For the everyday average user a cap is beneficial, you can never have enough capacitance.

You are living in the late 80's early 90's on your stereo advice. Most new caps have a ESR (Equivalent Series Resistance): < 0.0015 ohm, figure that into your equations.

I don't need a volt meter or a light sensor to know that my lights are not dimming since I installed a cap. For the record though I do have a volt meter that is hooked up in the car in the form of scangauge. Your thinking is what is flawed and very biased. I have given multiple instances of proving caps work, you have provided a Richard Clark test that was done probably 10 or 15 years ago, done with a audio competition cd that is continuous bass throughout the hz frequency range.

As far as your comment about they only reason they are still selling them because they are bread and butter, that is b.s. Show or tell me of some products that don't work but have been around since 1782.
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Thats what I thought!

http://www.caraudiomag.com/technical...ors/index.html

"Whatever you want to call them, EDLC, stiffening, supercap, or ultracap, it appears that they aren't of much help for the SPLer, except to stabilize the system voltage for the head unit and signal processors. However, for clean audio and improved transient power, these capacitors can extend the battery and improve the audio performance, including reducing harmonic distortion in the low frequencies." NUFF SAID.

I suppose the people at car audio magazine don't know what they are talking about either, maybe they are getting kick backs from the bread and butter shops make for selling the caps!

the 1 farad cap hasn't been around since the 1700's...and especially not marketed for the car audio industry. There are plenty of items that exist that don't work, but sell. There are thousands of "lose 4 inches off your waist in a week" products out there, as well as beauty products which claim to reduce the effects of age on a woman's face.

From my experience, most people with subs in their cars have at one time or another taxed their electrical system too much. Most people who have subs fall in the category of 16-24 yr old males, and too often than not, try to put as big of an amplifier as they can in their car without doing any math to see if the car can handle it.

For people running less than 600rms TOTAL in their car on a stock electrical, yeah, a cap probably won't hurt. But i've met more people who run more than 600rms to their sub(s) alone, than not.



Oh yeah... and about your statement about caps not being a load on the system... why is it then that if you leave a cap for a day they lose their charge mysteriously... You charge something, and instantly its already losing its charge, even without using it.


My statement remains, caps are the icing on the cake, upgrade the alt, all cables, and battery before even thinking about a cap.