Capacitors?!?!?!?
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New member Username: SqeeksPost Number: 2 Registered: Mar-05 | Can some please help.....I know that for every 1000 watts you need I farad! Im looking at buying the Kicker KX1200.1...this is over 1000 watts but I plan on running the amp At 2ohm which drops it to 600 watts rms...what size capacitor do I need...is 1 farad enough or do I go bigger? |
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KangarooJack Unregistered guest | sorry but i hate caps. as they could be lethal & could do more damage than good. See whether ya headlights are dimming when the bass hits b4 u go spending more $$. If it does change your stock alt. to a HO alt. (150 - 180amp) and change ya existing batt. to a deep cycle batt. So much better this way. Why buy the KX1200.1 when u only want to drive ya subs on 2ohms? U could buy smth else cheaper (600rms x 1 @2ohm) and still get the performance u want unless u want to add more subs in the future. |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 8246 Registered: Dec-03 | capacitors are a gimmick and don't help. if you want to improve current, get a bigger alternator |
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Treo?PPI? Unregistered guest | whatever!! Get a 1.5farad cap! It helps! |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 8280 Registered: Dec-03 | moron |
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Gold Member Username: Suleman36Maryland U.S.A. Post Number: 1630 Registered: Feb-05 | What about using a batcap 800 along with the HO alternator of lets say 200 Amps or a Capacitor ? Whould you even need it ? Im asking because in the owners manual to my CrossFire VR1000D they recommmend a designated battery for this amp as it says its recommended. |
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Silver Member Username: Eclipse2005Vicenza, Vicenza Italy Post Number: 174 Registered: Dec-04 | Would u use a cap durin SPL comp when u have to turn ur engine off? |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 8301 Registered: Dec-03 | capacitors do NOTHING for voltage rail issues. for SPL events you use a bank of deep cycle batteries to drive the audio system. battcaps are a gimmick as well due to the ultra-high ESR of the capacitance portion of the device. Also, you'd have to have not only a low ESR, but a distance of about 1' or less from the amps for a battcap to make any difference over a normal battery. even then all you'd do is lower propagation.. no effect on voltage aside from the battery itself. |
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Gold Member Username: CarguyPost Number: 3621 Registered: Nov-04 | You can't replace the need for HO alternator with any devices. A capacitor may help under very limited situation, that is about it. Trust me, I have tested it throughly. Unless your music contains very short bass beat with plenty of break in between, a cap won't help. What songs do you know that fall under that category? HO alternator will make caps and other devices useless. |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 8313 Registered: Dec-03 | the oltage of a capacitor follows the circuit voltage. if the voltage rails drop to 10 volts, so does the capacitor. thus, no help under any circumstances. |
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Gold Member Username: CarguyPost Number: 3626 Registered: Nov-04 | GlassWolf I hear you, but anyone that abuses their car/system so much that the voltage drops below 12.v is a moron. Anyways, the are situations where a cap can help. For example, if the songs you listen to contain steady short drums, it is just enough to be covered by the power stored in the capacitor. This can be negated if the user raises the volume beyond the reserved cap power. |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 8336 Registered: Dec-03 | the only thing the cap can do is decrease current demand response time, IF the alternator is already sufficient.. the misnomer is that a capacitor can help voltage issues when lights are dimming, etc.. which is completely false under any circumstances. Richard Clark has a very good article explaining this, over on carstereo.com I think it is. The capacitor(s) can also filter AC ripple, but most people don't even understand what that entails so that's sort of a moot point generally speaking. |
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Gold Member Username: CarguyPost Number: 3632 Registered: Nov-04 | Capacitor is like any other tool, it has it's advantages and disadvantages. If you know when to use it, it can be useful. With my HO alternator, it's not required, but I use it for different purpose. |
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Bronze Member Username: Audioguy22Post Number: 82 Registered: Jul-05 | Hi Isaac/Glass, whats the different purpose you speak of? I dont have a cap in my system but I do find it odd what folks say caps dont work or help in any way. If that were true that you'd also need to say that a second battery does not help either? What I'm saying is that a cap is much like a battery and the more the better? I wont aggree that caps are a rip off but I can say they dont help. When you get a better amp, there power supply has more caps(for more stored energy) so why wont having a bunch of caps help in some way? After all, it we removed are batteries are alternators would blow the first time you cranked your tunes(or burn up the brushes). As I see it, every little bit helps. Please tell me if I'm wrong on this. |
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Gold Member Username: InvainMichigan United States Post Number: 3212 Registered: Aug-04 | Think of a cap as a sort of second small battery that is able to supply quick bursts of current when there is a sudden very quick burst of demand. All power in your car still comes from the alternator. When your car is running, the alternator is supplying all the power, and recharging your battery, your battery just acts like a filter whent he car is running. When you have dimming lights, that meens you are pulling more amps then your alt. can produce, and your voltage drops. Low voltage is very easy to detect in lights, as very small dips make the lights dim. When you first add a cap, it is charged and ready to go. You play your system for a while, and it seem fine because your cap is supplying extra juice when your voltage rails dip, so you don't even notice the problem anymore. If your alt. is not big enough, your cap. will eventually be drained, and by that time your battery is probably close to dead as well. Caps add extra strain to charging systems, they don't help. When you add just a capacitor to a system with voltage problems, you are making the problem worse. |
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Bronze Member Username: Audioguy22Post Number: 85 Registered: Jul-05 | I reread that post and I'm not makin sence, let me correct it. I will aggree that caps are a rip off but I cant say they dont help. If we removed are batteries are alternators would blow. |
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Gold Member Username: InvainMichigan United States Post Number: 3217 Registered: Aug-04 | Honestly Benny, what in the world are you even talking about? If you remove the batteries, the car wouldn't start in the first place. The Alt wouldn't blow if the car was already running, because when your car's running all the juice is coming from the alt anways, the battery just acts as a filter. Your alt won't blow, everything else will. With no battery connected, you'd be running unfiltered pulsating current through all your electrical components, which will damage them. |
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Silver Member Username: Touche6784USA Post Number: 509 Registered: Nov-04 | uh dont think so benny. you wouldnt get the alternator working cause you wouldnt be able to start the car. learn to write better even that last post made no sense. |
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Gold Member Username: CarguyPost Number: 3645 Registered: Nov-04 | Read up on GlassWolf's post. If you're trying to replace the need for HO alternator then it won't work at all. However, if you use the cap as designed/intended, then it can be useful. The problem I've seen in most cases are, people use caps as a cheap way of replacing/ignoring the need for HO alternators. |
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Bronze Member Username: UcfsaxmanOviedo/orlando, Fl Post Number: 44 Registered: May-05 | It was my understanding that if you don't have any problems w/ your lights dimming and you're only running 1000 watts a capacitor and an optima battery might help but if you were to run more amps and 1000's of watts then you would need a HO alt. |
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Gold Member Username: InvainMichigan United States Post Number: 3223 Registered: Aug-04 | People need to learn to not just go by their lights. You should always check the voltage with your system running and the car on with a Multi Meter. |
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Bronze Member Username: Audioguy22Post Number: 86 Registered: Jul-05 | Hey! Joe, Good point. Make sure you get a cap with a volt meter built in. LOL! |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 8380 Registered: Dec-03 | ok I'm going to take a few of these comments apart to examine the misinformation that comes from advertising and a general lack of understanding on a few things like how a capacitor actually works, just to try to answer a few of these objectively. -whats the different purpose you speak of? a capacitor will reduce the response time for peak current demands between the alternator and amplifier, if and only if the alternator has enough current to maintain voltage rails, which means it is at or below the amount of current draw the alternator is capable of supplying. once the alternator is overdrawn, all bets are off. Also, a capacitor works to filter AC ripple caused by the alternator itself. Remember an alternator as the name implies, generates AC voltage, which is then rectified into DC voltage by a "voltage regulator" bridge rectifier. The DC voltage regulator isn't perfect, so the DC voltage can have an effect called AC ripple which basically means there's a pulsting to the voltage that shouldn't be there. A filtering capacitor can smooth that out to give a more constant 12-16VDC voltage rail. -you'd also need to say that a second battery does not help either? a second battery won't really help by itself if the alternator is too weak, while the car is running, correct. additional isolated batteries are used to increase runtime for the system when the car is shut off, and the alternator is no longer in play, so you can draw more current, for longer periods, before you kill the batteries. Also the isolator protects your starter battery from being drained by the stereo, so you can still start the car later. -What I'm saying is that a cap is much like a battery and the more the better? no. not raelly. a battery generates electricity through electro-chemical reaction to act as a power supply. technically if we still hand-crank started cars, we wouldn't even have a need for batteries in cars. A capacitor on the other hand, cannot generate current. It can only stor current for a brief period, and release that current in a burst as needed by the circuit it's in. A capacitor's voltage parallels that of the circuit voltage however, so if the alternator can't handle the demands, and voltage rails sag to say, 10 volts, guess what? Your capacitor will be at 10 volts as well, so it's not going to supply anything capable of boosting the voltage back to where it needs to be. Don't confuse current (I) with voltage (V). -When you get a better amp, the power supply has more caps (for more stored energy) so why wont having a bunch of caps help in some way? oh boy. ok, a power supply uses capacitors in a completely different way than you're trying to suggest. A capacitor in a power supply can have several uses, including filter capacitors, and current storage but remember in an amplifier, you're dealing with a regulated PWM circuit, with multiple voltage rails, ranging anywhere from 5 volts to 65 volts. You're really oversimplifying things for two reasons in this argument. one is to make your case, and the second is due to a lack of understanding about how electronics and amplifiers function. I can help you understand a little bit about amplifiers, if you have the patience to read a primer I wrote on their basic functions: http://www.wickedcases.com/caraudio/amplifiers.html -After all, it we removed are batteries our alternators would blow the first time you cranked your tunes(or burn up the brushes). As I see it, every little bit helps. Please tell me if I'm wrong on this. you're wrong on this. otherwise think about this.. when you have a dead or damaged battery, and someone jumpstarts your car so you can get home, or to an auto parts shop, why doesn't your alternator blow up as soon as you disconnect those jumper cables? The battery is in parallel with the alternator, and while it does filter voltage, keep in mind a few things: -a battery is only used to crank the car till the engine is running, to turn the starter. -once the car is running, the alternator puts out a higher voltage than the battery above idle, in order to put the battery into a charging state. -before we had alternators, cars had generators. we haven't always had alternators. -When you first add a cap, it is charged and ready to go. You play your system for a while, and it seem fine because your cap is supplying extra juice when your voltage rails dip, so you don't even notice the problem anymore. not quite the case. What actually happens is the capacitor masks the symptoms of the overstressed alternator by smoothing the spikes in demand for current. In other words instead of the lights dimming when bass hits, your lights will just be dimmer all the time, but by a lesser amount, because while there still isn't enough current for everything, the capacitor is hiding those spikes that let you see the problem. end result, you still kill your battery and alternator, your amplifiers still clip and fry your speakers and damage teh amplifiers, and you still end up replacing a lot of expensive parts.. but you now get to sit there and wonder what happened, because you thought your magical capacitor fixed all of your woes when it stopped the lights from dimming when the bass hits. |
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Silver Member Username: Dominirica012Charlotte, North Carolina US Post Number: 517 Registered: May-05 | damn glass nice post you send alot of people to school to do some more research  |
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Bronze Member Username: Audioguy22Post Number: 87 Registered: Jul-05 | Thanks GlassWolf. Big help in jogging my memory on how all this stuff works(I knew more as a kid that I do now). Too much DietCoke? By biggest problem is not watching the screen when I type, I sometimes change my line of thought and keep typing. This can make me appear to be more of a moron than I am. For the record, I dont have a cap installed but my put the one in that was givin to me a few days ago. Its kind of weird,it does not look like any cap I've ever seen. All it reads is The CAP by Alumapro? these anygood? its 5 Farads. I'm not an SPL dude and only have two VGA400.2's in the truck and a 80 Amp alternator, I just thought a cap might help keep my sound that much cleaner? I'd never buy one but I've now got one so what the heck. Once the cap is installed and I charge it with a bulb, is it cool just to leave hot all of the time? why does Alumapro require a hugh relay? Benny  |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 8394 Registered: Dec-03 | that cap you have is an older design, and as i recall, had a fairly high ESR, so not really useful.. but they look neat at least either way its not really going to hurt anything if ya want to run it |
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Silver Member Username: Mikechec9Chicago/atlanta Post Number: 523 Registered: May-05 | hey glass, don't mean to beat a horse but i have a soundtream SC-5CA cap. i have a 220(170) HO alt, o/1 cable, and 2 vga 1600.2's at 3000watts. 1) should i go ahead and install a kinetic 2400 battery (i understand that optimas are not optimal (npi) for high current audio systems due to resistance issues. yet i notice you run optimas. just curious if they will work in my app, or do i need the 400.00 kinetic? 3) Do you know the ESR on the cap? otherwise i will wait until monday. but the battery will be installed tomorrow if i need it, so i appreciate the input. thanks (it sure is purty)  |
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Gold Member Username: GlasswolfWisteria, Lane USA Post Number: 8405 Registered: Dec-03 | never had any issue with optimas, and who told you the optimas weren't well suited to audio systems? someone trying to sell you a $400 battery by chance? no idea what the actual ESR is for the cap RTFM is my suggestion or ask alumapro, if you can get any kind of customer service from them.. they suck at customer support.. especially trying to get them to cover warranty issues for Rainbow, whom they distribute in teh US exclusively now. |
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Silver Member Username: Mikechec9Chicago/atlanta Post Number: 546 Registered: May-05 | thanks. prob just saved over a couplehundred |
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Silver Member Username: Kd7nfrMontpelier, ID United States Post Number: 452 Registered: Apr-05 | I always used caps because they looked cool. Only reason I ever run one... I usually get one with a digital voltage display so I can watch the voltage too. And you would be amazed how much I can sell a used on for to someone that doesn't know any better... "You have a cap? How much did you pay for it?" HAHAHHA!!! |
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Bronze Member Username: Audioguy22Post Number: 88 Registered: Jul-05 | Nice Guy. But your right! When it comes to the dumb ones, I go for the street signs, I tell them its against the law to remove that sign but now you own it!LOL. |
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