Is there any reason to buy a cap?

[biggbabysweetz1]

oh man, i give up. i try explaining what CAN happen the BENEFITS of using a cap, and i get bombarded with...

^ What are you talking about, pretty much everything there was very very bad and false information. And alternators dont throw voltage spikes nemore, thats what regulators are for.

wow... if ur alt breaks, you buy a new one... not a cap.

EDIT: just cuz u went to school, doesn't mean you're right, moron. i'm not saying i know everything, but many guys here would disagree with you, and i'm wiling to trust them b4 i listen to what u gotta say after that shit.

and other crap. im done if youve got money to throw out to get 2kw of stereo stuff you CAN afford to replace stuff IF it goes out
also AGAIN i was stating the generals, ALL cars ARE different

Doesn't a cap store power for you amp?

So does your battery, assuming your alternator can't keep up with the load, in which case you should get a better alternator.

how fast can your battery put out that 2,000 watts? i know it cant put it out as fast as a cap

if you would like to read on capacitors heres a link http://electronics.howstuffworks.com/capacitor.htm
you can find out what a capacitor does exactly

[Jet-Lee]

Originally Posted by biggbabysweetz1

oh man, i give up. i try explaining what CAN happen the BENEFITS of using a cap, and i get bombarded with...



and other crap. im done if youve got money to throw out to get 2kw of stereo stuff you CAN afford to replace stuff IF it goes out
also AGAIN i was stating the generals, ALL cars ARE different



how fast can your battery put out that 2,000 watts? i know it cant put it out as fast as a cap

if you would like to read on capacitors heres a link http://electronics.howstuffworks.com/capacitor.htm
you can find out what a capacitor does exactly

Being an electronics major, you'd know that a battery doesn't discharge watts, same for a cap. An alternator isn't expensive, mine was $120 - core($40) so I only spent $80 on a 120amp alternator. My amp cost me $85 from a friend, NIB. Maybe you need to go back to school to learn what puts out what and how much.

[biggbabysweetz1]

wow...




Do you need an explanation of how electricity works?
If you take Volts X your Amps, you get your Watts
Voltage = Volts, current = Amps, resistance = Ohms, power = Watts
with me so far???
Lets try a simple equation...
Your vehicle runs 12 Volts, ok with me?
Your alternator puts out 120 Amps, Remember your Amps equal current.
We multiply 12 Volts X 120 Amps and you get what???
Thats right you get 1,440 Watts!


Now you say your system is 2000 watts. This may be true, but unless you've got it cranked fully while your listening to it it is not drawing that full 2000 watts. Depending on whats hooked up to it of course.
For the sake of experimentation say you have one 2,000 watt amp Peak, that just means its capable of supplying that much power to peripherals (in this case Subs and Speakers) at any given time. If youve got two 500 watt subs hooked up to it chances are it wont be drawing anywhere near 2000 watts.
Most companys when they advertise their subs and speakers say the maximum power they can take, lets say 1000 watts for now (this is also known as "peak").
This same subwoofer's RMS (root mean square) wattage is 400.
This means that this is the average amount of power an amp can give and a sub can take, remember if the amp is rated for 2000 peak it can dish out that full amount for a short period of time.
So for normal listening (radio cranked to 35 out of 40) those subs are only drawing 800 watts on average. Compare this to your alternator output. It can fit perfectly in this range, but add another subwoofer of the same wattage into the mix and you may be looking at some power issues.
3 subs 3000 watts total peak, 1200 watts total RMS. Hit a hard note and theres gonna be a lack of power to give.


I will grant you this, you are right your battery and cap do not put out watts... unless there is a draw
If there is nothing hooked up to the battery you have no amps or watts,
basicly you could say those are just measurements of usage.

It is also TRUE that capacitors block DC current. Capacitors in most mobile stereo systems are rated for something like 11 volts or so which allows constant flow while providing backup power.

Heres another experiment. Discharge both a battery and a capacitor, youll note that the capacitor is able to drain energy faster than the battery and also regain energy faster than the battery.

Seriously though you should have learned at least the basics of electricity in 5th grade.

Next time anyone posts saying im "full of shit", I would at least like a short explanation as to why this is not correct. With a little more detail than "your full of shit".
Im done fighting I just ask that everyone who disagrees checks out that link I gave on one of my other posts.
another little add-on is this, the name of the thread is " Is there any reason to buy a cap? " not "what are alternatives to buying a cap?"

so to answer that question Yes and No,
if you have a low output alternator that is still in good condition you can benefit from using a cap.
If you've got a monster alternator under the hood of that car you really dont need one.
maybe i should have just said that, instead of providing some generaly informative material.

[dave92cherokee]

Bigbaby and Jetlee you two need to stop the bitchin. Both of you are right. Jetlee on newer model vehicles simply buying a higher than oem output alt. will take care of everything. On older vehicles where the higher output alt. isn't available then they make caps. Bigbaby is completely right about how power works, how caps work and how systems work. I have a bachelors in electronics and own and run my own car stereo business. When a customer comes in with a 2003 suburban wanting 2 15's and a 3000 watt amp then I ALWAYS recommend a higher output alt. AND at least 1 farad cap to ensure that there will be no power problems. If same customer comes in with a 78 el camino and wants a pair of 10's and a 750 watt amp then I recommend bigger alt OR cap as both are not necessary. So in the end both of you are right there are instances where a bigger alt. fixes everything and there are instances where a cap is needed. Take my car for example I have gone one better and bought 2 additional batteries solely for the system AND 2 100 farad cap as I have 4 Hifonics XX Goliath 5k watt amps pushing 2 Kicker SoloX 18's in an entirely custom built fiberglass enclosure. So there ARE reasons for caps and not "just cuz people will buy them".

[biggbabysweetz1]

Thank you, and i must say i think you explained everything better than i did. i appoligize for bitching and arguing on an open forum.

[ngsm13]

Originally Posted by dave92cherokee

Bigbaby and Jetlee you two need to stop the bitchin. Both of you are right. Jetlee on newer model vehicles simply buying a higher than oem output alt. will take care of everything. On older vehicles where the higher output alt. isn't available then they make caps. Bigbaby is completely right about how power works, how caps work and how systems work. I have a bachelors in electronics and own and run my own car stereo business. When a customer comes in with a 2003 suburban wanting 2 15's and a 3000 watt amp then I ALWAYS recommend a higher output alt. AND at least 1 farad cap to ensure that there will be no power problems. If same customer comes in with a 78 el camino and wants a pair of 10's and a 750 watt amp then I recommend bigger alt OR cap as both are not necessary. So in the end both of you are right there are instances where a bigger alt. fixes everything and there are instances where a cap is needed. Take my car for example I have gone one better and bought 2 additional batteries solely for the system AND 2 100 farad cap as I have 4 Hifonics XX Goliath 5k watt amps pushing 2 Kicker SoloX 18's in an entirely custom built fiberglass enclosure. So there ARE reasons for caps and not "just cuz people will buy them".

Pics?

NG

[ngsm13]

Also, biggbaby...you're logic is flawed. You're just a bigbaby and won't admit it. What should happen, and what actually happens with car audio stiffening capacitors is different.

They are a band-aid for a weak electrical system, that's it.

Proper Electrical upgrades:
1) Big 3, using 1/0 wire
2) Replace stock batter with deep cycle ,such as Optima Yellow Top
3) Upgrade Alternator
4) Add another deep cycle battery in parallel

A capacitor is only ANOTHER strain on an already weak electrical system. Also, they are USELESS on long...hard...drawn-out bass. They recharge and discharge quickly...but if a song has a near 30-40hz tone for an extended period of time...it'll be just like that capacitor wasn't even there.

So, as stated before...the only use for a capacitor is to smooth out ripples in AC voltage.

NG

[Jet-Lee]

Originally Posted by dave92cherokee

Bigbaby and Jetlee you two need to stop the bitchin. Both of you are right. Jetlee on newer model vehicles simply buying a higher than oem output alt. will take care of everything. On older vehicles where the higher output alt. isn't available then they make caps. Bigbaby is completely right about how power works, how caps work and how systems work. I have a bachelors in electronics and own and run my own car stereo business. When a customer comes in with a 2003 suburban wanting 2 15's and a 3000 watt amp then I ALWAYS recommend a higher output alt. AND at least 1 farad cap to ensure that there will be no power problems. If same customer comes in with a 78 el camino and wants a pair of 10's and a 750 watt amp then I recommend bigger alt OR cap as both are not necessary. So in the end both of you are right there are instances where a bigger alt. fixes everything and there are instances where a cap is needed. Take my car for example I have gone one better and bought 2 additional batteries solely for the system AND 2 100 farad cap as I have 4 Hifonics XX Goliath 5k watt amps pushing 2 Kicker SoloX 18's in an entirely custom built fiberglass enclosure. So there ARE reasons for caps and not "just cuz people will buy them".

Me? Bitchin? No.......

I hate it when people boast about their "degree's" like they're some hot shit.

I do, however, appreciate your post clarifying both sides.

But, to add, ngsm is still right in that caps are useless in storing energy for a deep strong playing system.

BigBaby, I read about 10 lines of your post to notice you're trying to tell me what I learned in 5th grade.

[biggbabysweetz1]

BigBaby, I read about 10 lines of your post to notice you're trying to tell me what I learned in 5th grade

lol that was the idea. im done man. sorry for being a little bitch about the issue too

[PaulD]

Since most car stereo guys are bassheads .... not too much reason to buy one. Since these caps are a pass-thru, the + power cables are connected to the same tewrminal, I am not sure how much protection it would afford your stereo equipment. Most are only rated at like 20V, and some as love as 16V. I am guessing a heavy spike will only damage/destroy the cap


P.S. (in case no one said this already) Caps STORE energy, batteries "CREATE" energy thru a chemical reaction.

[jibbijib]

What about the people who cant afford all this other crap. Not everyone is made of money. Lets just say I want to run a 600 watt sub off of a 200 watt amp. Would it be necessary to get a cap? I have a new alternator installed on a 92 Mustang. It's not high capacity. Also, the head unit puts out 45wX4. Would I have to run a large gauge wire from the battery to power this, or can I get away with the regular wire, and run a large gauge from the head unit to the amp? There, all of you figure it out that way. Instead of trying to put 2kw systems together and trying to explain how capacitors won't work, or will work. The guy who asked the question probably only has a small system anyways. You have to focus on whether the small system needs one or not. So Igave an example. Don't get pissy about it either. Oh, by the way, I was told by many car audio professionals that you don't need a high wattage amp to get good bass out of your subs. You don't need to run at peak power to knock walls down. I have a friend who ran 4 10in subs off a 100 watt amp, and it pounded like crazy. Now he's runnin two mtx 12's and a 600 watt amp, and it hits even harder. So theres a wrench in your spokes for ya.

[Jet-Lee]

Your amp won't typically give your sub enough power. But a 200W amp shouldn't overdraw your system.

[CBFryman]

200w amp should have no more than 30-40a draw at the MOST. we are talking low eficency class AB Amps there. Most monosblocks are class D and most easily reach efficencies at or above 70%. Most car alternators have anywhere from 20-50a of extra current avalable.

Bigbaby, your idea that a 120a alt can only supply current for a 1440w is retarded to say the least. and here is why:

-Charging voltage is generally around 14v, since you are so good at ohms law ill let you figure out why this is significant.

-Amplifier efficency is not 100%, this is why amps heat up

-Most cars take at least 20-30a to run the coils, ECU, excetera

-Alternators are rated at crusing RPM at charging voltage. Once agian i will let you figure out why this is significant

-Once the alternator can no longer supply the needed current the battery begins to supply some of the current, this causes a total system voltage drop. since you have all these degrees and understand ohms law so well enlighten us to why this happens.

-As for caps being worth the money, the are not. lets say yo uget 2 2 farad caps. that will easily cost you $200 in most cases. for $200 you can have done big 3 and be well on your way to a Mean Green HO alt.

-Capasitors used in the way the car audio industry dont store energy for the amp, they give the electricity a place to go to maintain potential difference. Dumping all thoes electrons back down to the (+) side of charging system desrtoys potential difference and causes voltage drop. Of course you knew this because you are a physics expert

-Capasitors add resistance to the path for current. This may not be a big deal in daily apps but anyone who compeats or knows about compeating knows that a tenth of an ohm makes tenths of a difference on the Mic which what matters. If youve ever been to a competition and had a chance to get a close look at compeditors vehicles in high classes fuses arent used at all. even a massive ANL fuse as more restistance than the copper wire unbroken.

-Capasitors used for any other reason than to smooth minor voltage spikes will only show results on fast paced music for bass and on componet amps. if your componet amp is drawing so much current that it is causing voltage drop you either 1.) Are running a True Solid State Class A amps or a True Tube amp of 2.) Are Deff or 3.) Have some very inefficent mids/highs.

[biggbabysweetz1]

first off i do remember saying it was an example second not all cars are the same third i never claimed to be an expert at anything, i was noting that i do have an associates degree in modern electronics not a PHD.

im done arguing, so bash on my info all you want.
my message to everyone who reads this, AGAIN "take it or leave it"

[alphalanos]

Just goes to show that any fool can get a degree. Even me

Do the Big Three and Alternator.