Capacitor installation.

[TBlaar]

Hi everyone.

I'm new, and need some help.

My mate has just bought himself a 1 farad cap.

his amp was cutting out when the system was played loud.

we thought a cap might provide more stable power.

now, even with the cap, it does the same.

we are suspecting the amplifier, as he has just bought a brand new battery, and it's doing the same.

anyway, the question is this...

When installing the cap, we wired it directly into the system, as it should be. then afterwards, we heard and read about charging the cap first. when looking in the box of the cap, we found a resistor lying all alone in there. Now, how important is it to first charge the cap with the resistor, and secondly, could we have damaged it?

what do we do now? do we discharge it?

the wiring diagram that came with the cap is in russian i think.

do't you have to connect the resistor in a certain way, i understand a resistor also has a + and a _.

any input would be greatly appreciated...

T

Click to read more...

 

[boomanchu]

#1. Remove from package

#2. Find nearest trash receptical

#3. Place inside

#4. Turn the volume down !

 

[TBlaar]

ok. thanks for your input...

now tell me, what do you mean. do i throw away the cap or the resistor. how important is it to charge a cap before installing it?

i'm sure you guys can help, this is not a difficult question...

 

[KaeZoo 10+ year member]

The only reason to pre-charge a cap is that if you don't, the final connection will produce a big spark that can leave charred marks on terminals and occasionally blow fuses. Failing to pre-charge will have no effect at all on the cap's usefulness (or lack thereof).

Resistors have no polarity.

Even the proponents of capacitors wouldn't expect them to cure a situation where the amplifier is shutting off at high levels. You may have a poor ground, a voltage drop somewhere in the power line, or your subs may be wired for the wrong impedance. You need a multimeter to do any serious troubleshooting.

 

[Megalomaniac 5,000+ posts]

#1. Remove from package#2. Find nearest trash receptical

#3. Place inside

#4. Turn the volume down !

For only 98 posts this guy is a genius.

You should really consider ditching the cap,sell it or something. Is there a reason you have a cap?

Someobody tell you,you need them?

Bestbuy?Circuit City?

 

[gl0ck 10+ year member]

tell your friend he is a nubb.. and then beat him with the cap

 

[iceteebone 5,000+ posts]

probably the reason your amp is shutting off is do to insuffiecient current and adding a cap only made that worse. do a big 3 upgrade and a new alternator if you have to

 

[helotaxi 5,000+ posts]

Without knowing anything else about your system, I can pretty confidantly say that the cap has nothing to do with the problem. It is neither hurting nor helping at this point. Your amp is shutting down most likely because of an overcurrent on the output caused either by incorrect wiring of the subs leaving the amp with too low and impedance or the gain is set too high and the amp is clipping like a mother and tripping the overcurrent that way.

 

[wlmrs 10+ year member]

I just use mine to illuminate my trunk when the seats down,and oh yeah the voltage display.lol

 

[Megalomaniac 5,000+ posts]

I just use mine to illuminate my trunk when the seats down,and oh yeah the voltage display.lol

Lol, we rather use caps as a flashlight and a multimeterr,rather than its "meant to do" function

 

[TBlaar]

thanks for all the replies, guys.

ok, so i've thrown away the cap four times, i beat my mate with it, i've used it to illuminate his boot, i have used a multimeter, and i have turned down all the settings on the amp. none of this worked, except that from the beating my mate looks a tiny bit better.

The amp was a 2500W PMPO (christ jesus only knows what RMS).

The make was Ample-Tec (anyone ever heard of this?)

so, the amp was set to a +18 dB bass boost.

when we set this down, the cutting out dropped, but it still cut out.

so faarrkkk it, seeing that we live in south africa and make like no money at all, he decided to go out and buy another amp, a 450watt monoblock. this seems to run his sub fine, with absolutely no switching off.

common sense tells me the amp ****ed out amper too much loud banging....

now it's still good to drive some mids and shit... that shouldnt make them cut out...

thanks again, give more comments. some of you guys with the sarcastic commetns really make my day.

 

[S1n1sta]

Hey guys

You know, this forum isn't really meant for a lot of opinionated fools mouthing off and talking crap about things they seem to know absolutely nothing about.

A capacitor is a very good addition to any system that uses lots of power.

An amp needs a steady flow of power to operate at optimum effeciency. Most car batteries cant deliver that power, especially due to the fact that that one battery has to power other things like your headlights, or electrics in your engine.

Distortion created from a lack of power to your amp is MUCH worse than distortion gained from playing speakers too loud. A cap sorts that problem out and will give you better sounding bass and longer lasting speakers and amps.

Now, smartasses. All you guys who said to throw the cap away and all that bs, give me some insight into your deluded opinions, or rather just keep quiet.

 

[Mike yayo 10+ year member]

LOL at u for thinking these people dont know what there talking about(even though some dont like me), some of the people on hear know more than my local shops.lol^^ Didnt u just read when the guy said he added a cap and it did nothing..... From what i hear most people who know alot about car audio say caps are just for sho and then people at like cc or bb say they are a must so u figure it out/ I dont really know the exact reason im sure someone will post them though. But i think the cap is so small it has to be keep being recharged and it puts strain on the electrical system... Do the big 3 is wat most say will be better.

 

[KaeZoo 10+ year member]

Hey guys
You know, this forum isn't really meant for a lot of opinionated fools mouthing off and talking crap about things they seem to know absolutely nothing about.

A capacitor is a very good addition to any system that uses lots of power.

An amp needs a steady flow of power to operate at optimum effeciency. Most car batteries cant deliver that power, especially due to the fact that that one battery has to power other things like your headlights, or electrics in your engine.

Distortion created from a lack of power to your amp is MUCH worse than distortion gained from playing speakers too loud. A cap sorts that problem out and will give you better sounding bass and longer lasting speakers and amps.

Now, smartasses. All you guys who said to throw the cap away and all that bs, give me some insight into your deluded opinions, or rather just keep quiet.

If you're really comparing capacitors favorably to batteries for "a steady flow of power", then it appears you're also talking crap about something you know nothing about. There is no comparison at all between a battery and a capacitor in terms of how much steady current they can provide. This is incredibly easy to see for yourself: take a headlight bulb and connect it to a charged capacitor. Time how long it takes for the bulb to go out. You'll find that the capacitor is completely discharged in a matter of seconds. You won't have to bother doing the same test by connecting the bulb to a battery; obviously the battery can provide steady power for a much, much, much longer period of time.

Now, from reading your post it seems likely that you, like many others, think the battery is the main source of power for the vehicle electrical system. If that were true, then capacitors wouldn't even have a theoretical benefit, because a capacitor does not create power. It can only store it. It can never hold a higher charge than the voltage source it's connected to, nor can it have a lower charge than the voltage source it's connected to. The instant the capacitor drops below the battery's voltage (which would happen as soon as any load is placed on the cap) current begins to flow from the battery to recharge it. So the cap might as well not be in the system, since the battery can hold its charge for a much longer time than the cap can under any load.

However, the battery is not the main power source for the system. While the vehicle is running, the alternator is the power source. This is where the capacitor, in theory, becomes a benefit. The alternator produces a higher voltage than the battery, and the capacitor can charge to that level. So the battery doesn't provide any current at all while the engine is running, until the point where so much current is being drawn that the alternator reaches its limit and its output voltage drops. Once the voltage level drops below about 12.8 volts, the battery starts to discharge. So the benefit of the capacitor is that it can release its stored charge after the voltage drops below what the alternator usually provides, until the point where the battery starts to discharge. Once the battery begins discharging, the capacitor has used up its benefit: it CANNOT produce current at that point. It becomes useless, and if the load doesn't change, the battery will eventually drain.

The capacitor may have some benefit for the amplifier in this case: if there's a sudden, very brief demand for current beyond what the alternator can provide, which doesn't last so long that it drains the capacitor and the battery has to take over. Remember that a capacitor doesn't really store very much power! If the demand on the alternator continues for any length of time, the capacitor is useless. We're talking about lengths of time under 1 second here. Now, very short-term demands for current do exist when playing music, so in theory the capacitor can have some value. But it's highly debateable whether it makes an audible difference. I do know that lots and lots and lots of marketing money goes into selling capacitors, yet I've never seen a cap manufacturer invest in a real, controlled test that shows an audible difference when using their product. If someone knows of such a test, please link it.

Some people will promote capacitors as a way to reduce the strain on the alternator. I had a customer with an audio system under 1000 watts, and her alternator failed. I doubt the system had anything to do with the alternator's failure, but whatever. She had it replaced, and the shop that she bought it from refused to provide a warranty unless she added a capacitor to the system. That shows that even vehicle electrical system "experts" are muddled in their thinking about capacitors, because as you can see from what you've read above, a capacitor does nothing at all UNTIL the alternator is already overloaded! If the alternator can hold its normal voltage level, there's no current provided by the cap. It's only when the voltage drops, because of a high demand on the alternator, that the cap begins to do anything at all in the system.

 

[Megalomaniac 5,000+ posts]

no bass boost sir