Sad fact is alot of manufacturers do not post ESR values. They only display "low-esr" Repuitable companies like stinger clearly display the ESR of their caps (at least they used to haven't checked in a few years). *edit* just looked they no longer display it //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif Stinger caps used to have fairly low ESR.You can do the math yourself and determine the voltage drop across the cap for a given load I*ESR=voltage drop (which is simplistic way to look at it). ESR isn't a static value it's frequency dependent which makes things a little more complicated and harder to explain. The load also isn't static it varies so current also changes. Caps are put in parallel on an amplifier because its a cheap way to get an equavilent large capacitance low ESR capacitor. Not because a larger low ESR cap isn't available. Good caps are expensive and when you start talking about thousands of products every penny adds up. Then you also have supply issues. Specialty products may be easy to get one day and extremely hard to get another. Using easily available products is just good design practice.
The point at which caps are useful are the transients. The instant a bass note starts. Large instantanious current is required. As the diagram in the link posted clearly shows. They are not intended to supply current over long periods of time.
The neon light and voltage displays annoy the hell out of me, they serve no purpose.
As I mention previously if your lights "flicker" a cap would be useful and you have no reason to upgrade an alternator. If your lights dim and keep dimming it's time for a new alternator.
I didn't come here to teach a lesson which is why I didn't point any fingers. I gave up on that long ago. Post falls off and 20min later someone post the same question. And the same arguement continues. If you dont want to use them it doesn't bother me. But at least give correct information even if you can't explain the other side or don't want to spend the effort explaining. Caps work when they are used correctly they don't work when you use them as batteries.
No, actually they use an array of small caps exactly because they get lower ESR that way.
The lesson on transient power demands was fun to read, but hardly new material. Like we are gonna go "oh wow music is transient, never knew that... he's right caps have a purpose!" You reveal the age-old notion of what a cap is suppose to do for a stereo, as if we have no idea. We get it, you don't. The multi-farad, illuminated high ESR caps sold today serve virtually no real purpose. You agree with this notion pretty much, but then go on to imply 'misinformation' blah blah blah.
If your charging system is sufficient, there is no real need for an external capacitor. Lets look at the other things recommended to upgrade in the charging system: big 3, battery, alternator. Which, if any, of these upgrades would you place buying a cap ahead of? //content.invisioncic.com/y282845/emoticons/eyebrow.gif.fe2c18d8720fe8c7eaed347b21ea05a5.gif The correct answer is, none of them. Adding external capacitance will not make up for having insufficient wiring, an insufficient alt, or a worn out battery. So that leads to the idea that a cap should only be added once all those other things have already been addressed. And, once you have addressed those other, much more important components/areas, you will find your perceived need for external capacitance is gone.
Flickering headlights, add a cap to your stereo? Uhm, why? If the flickering bothers you, put caps on your headlights. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif Dimming headlights? Well that means you didn't upgrade the big 3, the battery, or the alt yet... and that you should.
As far as cheaper amps using less on-board capacitance... well... if you want to buy a Boss amplifier and then try to squeeze every ounce of fidelity out of it you want, sure knock yourself out and add a cap too. Heck add a couple. But the simple fact is if you bought an amplifier that
requires external capacitance, you bought an amplifier that requires being thrown away.
Now you are bringing math into the discussion (boooo!) and yet I still dont see you proving any real situation in which external capacitance is
required. Again you only seem to want to argue what has already been said, yet lay no real foundation for your own stance. You like to end all your posts with the idea that caps, when used correctly, "work". I guess you mentioning 'when used correctly' proves they have a real-world use? What is 'used correctly' exactly? On a cheap *** amplifier running off piss-poor wiring and a worn out battery... and your music taste demands perfect transients? Great point.
